Free Communications, Poster Presentations: Chest, Abdomen, and Pelvis

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-81.

A Severed Kidney As A Result Of Blunt Trauma In A High School Football Player

Abstract

A 15 year old, junior varsity, high school football player was running with the football when an opposing player tackled him from the left side. The athlete was down on the field in apparent pain. As the certified athletic trainer approached the athlete on the field, the athlete got up and walked toward the certified athletic trainer. The athlete complained of significant pain at the abdominal area and moderate pain at the left flank area. The certified athletic trainer instructed the athlete to lie down in order to be evaluated. After lying down, the athlete complained of difficulty breathing and an urge to urinate. The athlete communicated these complaints in a calm manner with no signs of distress. At the time of initial evaluation, all of the athlete's vital signs were normal. No signs or symptoms of muscle rigidity, rebound tenderness or sharp pain were present. At this point, the athlete did not complain of low back or kidney pain, however, he was point tender at the left flank and abdominals. The athlete was transported to the hospital immediately by the on-site ambulance. In the ambulance, the athlete exhibited hematuria, urinating approximately 250 cc of dark red urine and blood. Initial differential diagnoses included thoracolumbar spasm, abdominal pain, kidney contusion, and renal laceration or fracture. At the hospital, a computed tomography (CT) scan was administered, and it was at this point that the athlete's vital signs rapidly deteriorated. The CT revealed a severed left kidney, which was hemorrhaging considerably. Through emergency surgery, a left nephrectomy was performed to remove the hemorrhagic severed left kidney. The surgical procedure was completed without incident. The athlete recovered fully and was cleared by his physician three months later to compete on the high school's varsity basketball team. The athlete, however, was no longer allowed to participate in football. Since his nephrectomy, the athlete has not had any complications. This case was unique for various reasons. The athlete was taking beta-blocker medication for another systemic condition. The emergency room physician concluded that the athlete's deteriorating vital signs were masked at the time of injury and during transport to the hospital due to this medication. Consequently, an accurate diagnosis could not have been made for this life-threatening injury without the CT imaging. Also, the physician concluded that the athlete's kidney was severed most likely due to the fact that he had a very low body fat percentage and lack of internal kidney support (mesentery). In most instances, when a single blunt force to the posterolateral portion of the upper lumbar and lower thoracic region occurs, resulting in signs and symptoms of pain and point tenderness in the contact area along with the desire to urinate, a kidney contusion is often suspected. However in this case, the athlete's physical attributes along with the manner in which the force was applied lead to a severed kidney, creating a life-threatening situation. The athlete was first suspected to have a minor injury exhibiting muscular spasm and pain, but the signs and symptoms later suggested otherwise. This clinical case report reflects the importance of scrutinizing the signs and symptoms of seemingly minor injuries, especially when the potential for organ involvement exists. In fact, these minor injuries may be more significant than they seem, and may even be life threatening.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-81–S-82.

Chest Pain In A Female Collegiate Swimmer

CK Ames ¹, JM Hauth ¹, MR Miltenberger ¹

Abstract

An 18-year-old female college swimmer (wt. 128 lbs. ht. 67 in) reported to the athletic training clinic complaining of sharp pains on the left side of her chest. The athlete has had intermittent pain for approximately 9 months (high school swimming season). The athlete's pain was said to be dull for a period of about three weeks but recently became sharper and more disabling. The patient's history revealed no previous chest or cardiovascular pathologies or anomalies; however, she was seen in high school for a similar complaint. Tietze's syndrome (costochondritis) was suspected at that time. Evaluation of this athlete was completed by the family's physician approximately 72 hours after a visit to the emergency room and referral from the athletic training staff. Physical examination revealed a “dull, heavy” pain along the top of the chest and into the sternum. At times the pain was sharp and was followed by a “burning” sensation. Less discomfort was reported in the morning hours; the pain did worsen throughout the day. The pain was worse immediately after practice, reaching an 8 out of a 10 on a standard pain scale. Pain increased upon inhalation, and palpation revealed nickel sized hard, painful lumps over the athlete's ribs and chest. Point tenderness during palpation was noted along the ribs from the axillary region to the sternum. No crepitis, nausea, headache, ecchymosis, shortness of breath or radicular symptoms were reported. The athlete's heart rate and blood pressure were within normal limits. Diagnostic testing to rule out the following were executed or prescribed: Orthopedic - Rib fracture, pectoral strain, sternum fracture, costochondritis Cardiopulmonary – asthma, heart attack, allergic reaction, respiratory infection, pneumothorax. During an emergency room evaluation, EKGs, radiographs and MRIs were negative for any orthopedic or cardiopulmonary pathologies. Seventy-two hours later, the athlete followed up with her family physician who suspected Tietze's Syndrome. After a three month period of decreased activity and due to the continuing/recurring complaints, the athlete was referred to an orthopedic surgeon for evaluation and a second set of radiographs were ordered. These too presented negative for any pathologies and a diagnosis of costochondritis (Tietze's syndrome) was confirmed. The clinical course for this athlete included initial treatment with high doses (800 mg) of NSAIDS and ice before and after bouts of exercise. The symptoms resolved during a three-month off-season/conditioning period, however, when the athlete began intensive preseason workouts, similar symptoms returned. The physician referred the athlete to the athletic training room for treatment and rehabilitation. The treatment regimen consisted of therapeutic heat and massage over the sternum and pectoralis muscle region. Treatment / rehabilitation sessions were concluded with cryotherapy. The program included a regimen of theraband strengthening exercises for the shoulder and chest musculature. The treatment plan has been successful in modulating the patient's pain and allowing her to participate fully in intercollegiate competition. This case is unique because the initial onset and diagnosis occurred while the athlete was in high school. Tietze's, a sternocostal joint inflammation (costochondritis), is uncommon in this age group. Painful palpation directly over and into the joint is a key sign. The syndrome will commonly mimic cardiac pain and the pain may even radiate down the arm on the affected side. Tietze's usually affects the 3^rd or 4^th ribs, affects men and women equally and usually affects individuals between the ages of 20–40. Physical activity and sudden movements aggravate Tietze's; however, it is normally classified as idiopathic. In this case, Tietze's syndrome recurred due to overuse and the associated increase in activity during the preseason training period.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-82.

Differential Diagnosis Of Insidious Hematuria In A Collegiate Male Lacrosse Player

JR Scifers ¹, JA Manners ¹, JL Gleisner ¹

Abstract

The athlete is a 20 year-old male lacrosse player who reported to the athletic training room in October 2001 with complaints of blood in his urine. The athlete denied any history of trauma or any other possible mechanism of injury. Further evaluation revealed no flank pain, dysuria, high blood pressure, or infections. The athlete did report a history of recurrent hematuria once or twice a month with no associated conditions beginning in 1997. In July 2000, the athlete suffered a head injury and was treated at the emergency room where he was found to have microscopic hematuria. The athlete was then referred to an urologist where it was determined an intravenous pyelogamy (IVP) should be performed to rule out a kidney stone or other blockage of the urinary tract. Radiographs were within normal limits and the athlete had no further gross hematuria until 2001. After seeing the athletic training staff in 2001 for this repeated episode of gross hematuria, the athlete was referred to the student health center. The student health center in turn, referred the athlete to see a nephrologist. The initial impression of the nephrologist was a rare condition known as IgA nephropathy or Berger's Disease. IgA nephropathy occurs when there is inflammation of the renal glomeruli and deposits of IgA (immunoglobin A) protein in the kidney. This condition is characterized by episodes of hematuria and proteinuria with no other symptoms of a kidney disorder. The hematuria most commonly occurs during an upper respiratory infection. With this condition, there is no known etiology or treatment. In some cases, a low protein diet may be recommended to prevent chronic renal failure. With this athlete, the nephrologist performed a urinalysis, which detected trace protein but no other abnormalities. An abdominal sonogram was then ordered to assess the condition of the kidneys, liver, pancreas, and spleen. These test results also came back within normal limits. Next, a twenty-four hour urinalysis was ordered to assess the level of protein and creatinine in the urine. High levels of either substance can indicate a problem with kidney functioning. This test was also negative. The nephrologist then recommended a renal biopsy. This could potentially confirm IgA nephropathy by demonstrating the buildup of antibodies in the glomeruli. The biopsy was completed in March 2002 to the lower left kidney. The surgical intervention was complicated by a large retroperitoneal hematoma that extended from the anterior left kidney to the anterior descending colon. The athlete was hospitalized for several days until the hemorrhage was controlled. No antibodies were found in the kidney from the biopsy and IgA nephropathy was ruled out. The athlete was monitored for several more days to assure no other surgical complications would arise prior to being discharged from the hospital. The nephrologist's final impression was that the athlete was simply “spilling red blood cells” as a result of heavy exercise. The athlete was cleared to begin both an aerobic and strengthening program. He completed this program during the summer of 2002 and competed during the 2003 season. Although the athlete occasionally experiences bouts of hematuria, he continues to train and compete without further incident. This case demonstrates a unique course of diagnostic testing and treatment in an athlete with insidous onset hematuria.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-82.

Acute Abdominal Pain In A Collegiate Soccer Player

RB Smedley ¹, ML Boquiren ¹, SM Zinder ¹

Abstract

A 19-year-old Division I female soccer player, with no prior history of abdominal trauma, presented on the field with acute abdominal pain and shortness of breath following contact with an opposing player's knee. On initial examination, the athlete displayed minimal abdominal rigidity despite some guarding, no obvious edema, ecchymosis, or gross deformities. She complained chiefly of severe general abdominal pain and moderate to severe pain during inspiration. Physical examination showed general point tenderness over the entire abdomen with exquisite tenderness over the upper right quadrant. Her pulse was strong and elevated, but within normal limits due to her recent physical exertion. Blood pressure was not tested. She was carried off the field and into the locker room for further examination. A detailed examination approximately five minutes after the initial insult revealed that the athlete's pulse had weakened and her dyspnea increased. Due to the diminished vital signs and continued tenderness over the upper right quadrant, it was decided to transport the athlete to the emergency room. The differential diagnosis at this point included diaphragmatic spasm, traumatic pneumothorax, costochondral trauma, and internal abdominal pathology. On admittance to the hospital, the athlete was given a chest X-ray that ruled out any costal fractures or lung pathology. Blood work revealed a slightly decreased hematocrit suggesting the possibility of an internal hemorrhage. She was then administered an abdominal C-T scan which showed a large, complex laceration of the posterior segment of the right lobe of her liver. Surgical intervention was deemed unnecessary as the outer membrane of the liver was not compromised. The athlete was admitted to the intensive care unit for observation and intravenous pain medications. She remained in the ICU for 48 hours and was released to a regular hospital room for the next 24 hours. On release from the hospital she remained home with her parents for five days where she was restricted to complete rest. After return to school, the athlete was re-evaluated by the physician and was progressed to a gradual return to activities of daily living. At eight weeks post-injury the athlete was allowed to resume light, non-jarring physical activity (bike, swimming, etc) with progression to light jogging. Initial jogging bouts revealed slight abdominal discomfort, progressively resolving over the next two weeks. Twelve weeks following the initial injury she was fully released for competition, and has suffered no residual complications. Injuries to the liver are relatively uncommon in athletics, however, they should always be part of the differential diagnosis when evaluating abdominal trauma.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-83.

Ureteropelvic Junction Obstruction In A Collegiate Lacrosse Player

R Liddle ¹, K Lundquist ¹, J Walter ¹

Abstract

A 22-year-old male collegiate lacrosse player reported to the Emergency Room in the middle of the night with severe right abdominal pain. The athlete denied any trauma to the area. He was seen by an Urologist in the Emergency Room, who ordered a sonogram. The sonogram revealed an enlarged right kidney secondary to Ureteropelvic Junction (UPJ) obstruction. UPJ obstruction involves a congenital defect in the joint between the pelvis of the kidney and the ureter; this defect can lead to a backup of fluids in the kidney. This blockage will cause inflammation and thus enlargement of the kidney. Due to his enlarged kidney, the athlete was at a high risk of rupture if he sustained trauma to the area; he was therefore unable to participate in contact activities until the inflammation resolved. The athlete was treated with pain medication while in the hospital and rest for several days. A sonogram was performed three days later and showed no inflammation of the kidney. The Urologist cleared the athlete to return to play as tolerated. Approximately one month later the athlete had another “attack” prior to a lacrosse game. The athlete reported to the Athletic Training staff with a “sick” feeling during pre-game treatments and quickly progressed in symptoms. The athlete appeared pale and clammy, and complained of severe right flank pain and nausea. Within minutes the athlete began vomiting. The athlete was immediately taken to the Emergency Room, where a CT scan was performed and confirmed an enlarged kidney. The athlete was given pain medication while in the hospital and was released later the same day. The Certified Athletic Trainer followed up with the athlete the following morning and the athlete stated that he felt much better. The Certified Athletic Trainer contacted the Urologist at that time, who stated that as long as the athlete continued to remain asymptomatic he was cleared to play for the remainder of the season. The physician also stated that he recommended surgical intervention after the season to resolve the UPJ obstruction. The athlete completed the remainder of the season with no further problems. He is currently not participating in any athletics. He has not had any more attacks and has not yet received the surgery. Differential diagnosis may include the following conditions: renal disease, renal failure, kidney stones, urinary tract infections, bladder infections and low back pain. UPJ Obstruction is quite rare in collegiate athletics; it is typically found in children. The condition is different from typical “low back pain” and other illnesses an athlete might experience, and the Athletic Trainer must be aware of the signs and symptoms of this condition. Due to the significant risk of kidney rupture, it is vital that the athlete be withheld from participation in contact activities while the kidney is enlarged and the athlete is symptomatic.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-83.

Umbilical Pain In A Collegiate Football Player

PN Manwaring ¹, KB Pirog ¹, TJ McCarthy ¹, RS Waskowitz ¹

Abstract

A 22 year-old Division I football offensive lineman complained of pain and irritation to the umbilical area during double session practice. The athlete noticed a small amount of clear fluid draining from the umbilical area after performing individual football drills. He was able to continue with the remainder of practice without any discomfort. Upon initial physical examination, the athlete presented with pain and point tenderness to the umbilicus and surrounding tissue. There was localized erythema measuring approximately 10cm in diameter. The athlete did not present with an elevated temperature. After a 24-hour period, the athlete returned to the athletic training facility and presented with a small pustule located on the inner surface of the umbilical wall, which was enlarged to the size of a marble. The area of erythema had increased to approximately 15cm. All tissue surrounding the umbilicus was warm to the touch. At this time, the athlete was unable to participate with any contact related activities. Differential diagnosis: Contusion; hematoma; umbilical infection; umbilical hernia; appendicitis; diverticulitis; umbilical abscess. Blood work revealed a minimally elevated white cell count. The CT scan revealed a fluid collection immediately below the umbilicus, with the underlying fascial layer intact, no obvious hernia; no intra-abdominal pathology. The athlete was taken to the emergency department at the local hospital for evaluation. Examination by the general surgeon was significant for mild cellulitis and tenderness at the peri-umbilical region. Also noted was a reddened bridge of skin encapsulating a brown fluid-filled cystic space. After reviewing the CT scan results, the physician's diagnosis was an umbilical abscess. The surgeon excised the umbilical skin bridge allowing the purulent fluid to drain. A small sampling of fluid was cultured for identification of bacteria. The cavity of the superior umbilicus was packed with beta dine-soaked sterile gauze and covered with a sterile dressing. The athlete was placed on 500mg of Ancef antibiotic for 10 days. He was restricted from athletic related activity for 2 days and instructed to report back to the hospital for follow-up care and wound evaluation. The athlete was reevaluated 48 hours later in the emergency department by the general surgeon for a dressing change, which included packing removal and cavity irrigation. Also, effectiveness of the antibiotic was determined to be appropriate as the swelling, redness and pain had subsided significantly. He was able to return to football the next day without any difficulties. Superficial and cutaneous skin infections are not an uncommon finding in athletes. Commonly the presenting findings are sensitivity, mild pain and erythema and a localized skin reaction consistent with dermatitis. This case represents one of several different skin reactions that we have seen in our football players at our University. We are practicing and playing on the latest generation of synthetic field surfaces (“Field Turf”) installed in the stadium this past year. Because of the increase in skin-related issues, we are now more focused on evaluating skin reactivity in our athletes practicing on this surface.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-83–S-84.

A Survey Of Coaches' Knowledge, Attitudes, Skills, And Behaviors Regarding The Female Athlete Triad

JW Lassiter ¹, CA Watt ¹

Abstract

This survey research investigated women's sports coaches' knowledge and attitudes related to the female athlete triad and skills and behaviors that might impact prevention and intervention efforts with their female athletes. Surveys were sent to 14 western New York public schools and 80 coaches responded sufficiently for analyses. Only 38% of coaches correctly named all 3 components of the female athlete triad. Although coaches indicated comfort discussing the triad with their athletes, they stated that more knowledge about the triad would significantly increase their ease. Coaches reported participation in prevention and educational behaviors related to weight and nutrition more than behaviors specifically related to the triad; intervention behaviors related to weight and nutrition as well as the triad were lacking. Comparisons found that female coaches had more knowledge and communication skills than males. Similar results were found in coaches with a history of an eating disorder and those with previous specialized training on the triad. Knowledge, attitudes, skills, and behaviors of coaches differed very little when examining years of coaching experience, type of degree, level of education, and type of sport coached. More education is necessary to prepare coaches to participate in prevention and intervention. While almost all coaches could benefit from education, targeting male coaches, those who have no previous training on the subject, and coaches of at risk sports may prove most beneficial. Supported by a grant from the NATA Research & Education Foundation Osternig Master's Grant Program.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-85.

Twenty One-Year-Old Male Loses Consciousness After Running In The Cold

AJ Zaino ¹, LD Johns ¹

Abstract

The purpose of this study is to report a unique incident involving a 21-year-old male college student. The affected had participated in athletics for years, including Division I lacrosse. However, the athlete was participating as a recreational runner at the time of incident. Following a moderate to fast pace 2 mile run on a cold night in April (29°F), the runner experienced body itchy sensations followed by swelling in the facial and lip regions. The athlete had experienced approximately three incidents previous to this case, of cold induced wheals. However, he had not sought out medical attention because of the low severity. The individual had been prescribed Clarinex, on an as needed basis primarily for hey fever. On the day of the incident, the pollen count was reported to be significantly elevated; however, the athlete did not feel a need to take Clarinex that day. Roughly 2 miles into his jog/run the affected began to experience bodily itchy sensation. The sensations intensified over a roughly 2 minute span. Next, extreme facial and lip swelling began followed by hypotension and dyspnea. The symptoms worsened, and the individual was forced to place himself on the ground with his lower extremities in a slightly elevated position. At this point the college's nurse was contacted. Upon transfer to a wheelchair (to transfer to the medical health center on campus) the involved lost consciousness, and remained unconscious for approximately 20 minutes. The individual was transported to Yale New Haven Hospital by ambulance. Upon arrival he had diffuse erythema in the skin with hives; the eyelids had swollen shut and considerable swelling of the tongue and lips. Respiratory rate was 24 with bilateral wheezing. Cardiovascular examination showed regular rhythm. Abdominal and neurological evaluations were normal. The white blood cell count was slightly elevated (14.8 × 10³/L, normal range 4.0–11.0 × 10³/L), but the differential between white blood cell count, hemoglobin and hematocrit was normal. Conditions that present signs and symptoms similar to those experienced by the affected are: cold and/or exercise induced anaphylaxis, cholinergic urticaria, cold urticaria, and vibratory angioedema. Once admitted to the hospital, blood was drawn, analyzed and an immunologist was consulted for the case. Findings from the examination included: (−) pressure/scratch test, (+) ice compression test. The ice test was administered with a single cube and was held on the patient's skin for approximately five minutes. Upon removal of the ice, redness and an elevated area of skin was apparent yielding a (+) finding. All laboratory blood analysis returned within normal ranges. Once inside the ambulance the patient was given oxygen, Benadryl, Solumedrol and Epinephrine. At the hospital, prednisone and epinephrine were administered and the individual's vital signs were closely monitored. The patient was admitted to Yale New Haven Hospital for overnight observation with a diagnosis of anaphylaxis. However, the question remained as to whether anaphylaxis was triggered by cold alone or a combination of cold and exercise. The following afternoon he was released and given a prescription for a prednisone taper, Zyrtec, and Pepcid AC. The patient was instructed in self-administration of epinephrine and received an epinephrine pen. The individual returned to full activity, with a restriction of exercise under 50° Fahrenheit. This particular case is unique in that the individual had participated in cold weather physical activity for 15 years prior to this life threatening event. The only signs and symptoms included three outbreaks of cold induced wheals during outdoor physical activity over the past 6 years. However, the number of asymptomatic cold exercise exposures far out numbers the three incidence that triggered dermatological symptoms. From the time of incidence, the individual has regularly taken Zyrtec, exercised weekly and has been asymptomatic. Five months have elapsed from the time of anaphylaxis (May–September) and the temperature has remained above 50°C during times of physical activity. This case highlights a largely asymptomatic condition that could quickly turn into a life-threatening situation, even if the individual had experienced no life threatening incident in the past.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-85–S-86.

Acute Lateral Knee Injury In A Collegiate Softball Player

CM McAllister ¹, SW Stevens ¹

Abstract

A 19 year old NCAA Division I collegiate softball shortstop with no previous history of left knee injury sustained a lateral knee injury. The athlete was covering second base on a steal attempt. As the base runner slid into second base, she collided into the athlete who was straddling the base to receive a throw from the catcher. The runner slid into the medial side of her left knee delivering a varus force to the medial portion of the shortstop's knee. She experienced immediate discomfort and was unable to continue participation. Upon initial examination, the athlete's primary complaint was intense pain on the lateral aspect of her knee. She was also point tender over the lateral joint line and reported feeling a pop. There was no obvious deformity or immediate swelling. A varus stress test yielded no endpoint. Any motion resulted in discomfort. The athlete was assisted off the field NWB. Her knee was wrapped with an ACE bandage, iced and she was then transported to the hospital due to the intensity of pain and guarding. Initial differential diagnosis included a lateral collateral ligament sprain and a lateral tibial plateau fracture. Plain film x-rays revealed a fracture of the lateral tibial plateau. Within two days the athlete underwent arthroscopically aided internal fixation of a lateral tibial plateau fracture. The ORIF showed a separation in the lateral joint line with a central depression of a portion of the joint. The fracture was elevated slightly above the joint line using elevators and bone punches. Two lateral incisions were made and through each a 65 Kinsaw screw was inserted and secured. C-ARM images as well as visual arthroscopic inspection confirmed the reduction. Four days after surgery staples were removed. She returned to school and underwent symptomatic treatment to reduce pain and swelling that consisted of RICE and TENS under the care of an athletic trainer. Three weeks after surgery, the athlete returned to the doctor with no complaints of pain. X-rays showed a well reduced and fixed fracture and a loose washer in soft tissue. She returned home for the summer and began physical therapy with ROM and strengthening while remaining non-weight bearing. Again at six weeks post-op, x-rays showed good position of the screws and hardware. ROM was greatly increased; exercises to improve ROM and strengthening were encouraged. X-rays obtained again at eight weeks postop confirmed healing. The athlete continued physical therapy through August when she returned to school to complete her rehabilitation with the athletic training staff. Progress was steady and went well throughout September and October. There were periodic complaints of soreness at the screw locations. Activities were modified and the soreness decreased. The athlete had achieved about 90% functional strength compared bilaterally by five months post-surgery. She was able to do all activities except heavy deep squatting and distance running. Approximately six months post-surgery, she complained of sharp pain in her knee after a conditioning workout. She was referred to the orthopedic surgeon who performed the initial evaluation and subsequent surgery. X-rays revealed the fracture had dropped mildly. She underwent surgery two weeks later to remove the screws from the previous ORIF and to arthoscopically examine the fracture and ensure it continued to be well positioned. The surgical diagnosis was painful hardware in the left knee after a posterior tibial plateau fracture. The hardware was removed successfully, including the free-floating washer. A diagnostic arthroscopy was also performed which revealed mild chondromalacia on her lateral joint line and a normal articular surface where the fracture was previously noted. She was instructed to begin light strengthening and cycling for four-six weeks. Heavy activity was restricted due to the defects left by the screws.This case is of particular interest due to both the unusual mechanism of injury and the painful nature of the screws. It is important for athletic trainers to be aware of the possibility of an avulsion fracture following a blow to the medial knee. Injuries such as this one are more common in growing athletes, but cannot be overlooked in skeletally mature athletes. This case also demonstrates the importance of continued follow-up and examination to identify surgical complications such as migration of surgical hardware.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-86.

Skin Infection Within Eight Collegiate Football Players

E Noe ¹, A Puls ¹, D Bishop ¹, KL Hamstra ¹

Abstract

Within a two-day period, eight collegiate athletes were referred to a physician for infected wound care. Players were male, 20–22 year-old, Division 1-AA athletes participating in the 2003 preseason football training camp. The group consisted of one tightend, one offensive lineman, one linebacker, and five defensive linemen. Four of the eight had one previous occurrence of a staphylococcus skin infection within the past two years. The other four had no history of staphylococcus skin infection. Initially, each athlete reported to the athletic training room for treatment of an abrasion wound caused by either synthetic turf or friction from protective bracing or equipment. Two of the wounds were located on the elbow, and the remainder were found on the distal anterior arm, buttocks, anterior knee, posterior knee, anterior lower leg, and posterior lower leg. Within 1–2 days of noticing the turf burn or abrasion, a red pustule or rounded nodule developed on or around the wound. Five of the eight athletes complained of pain with the initial pustule or nodule and three reported pain within 1–2 days after the onset of the pustule or nodule. Differential diagnoses included folliculitis, pustule, boils, impetigo, toxic shock syndrome, cellulitis, staphylococcal skin infection, Staphylococcus aureus infection, and methicillin-resistant Staphylococcus aureus infection. The eight athletes were referred to the team physician for blood work and cultures of the infected area. Results of the diagnostic tests were all positive for a staphylococcal skin infection. Five of the eight athletes received solely oral antibiotics three times a day for one week. Wounds were scrubbed with a topical antiseptic twice a day, treated with triple antibiotic ointment, protected by a non-adherent pad, and secured with elastic tape. Significant healing occurred within approximately two weeks. The physician cleared these five players for immediate return to play provided the infected area was covered. The athlete with the infected buttock had outpatient surgery where the area was incised, drained, and packed with gauze. The physician prescribed oral antibiotics three times a day for one week, injected the athlete with antibiotics immediately following the surgical procedure, and cleared the athlete for participation three days post-op. The player with the posterior lower leg infection underwent inpatient surgery where the wound was incised, drained, and packed with gauze. The athlete was hospitalized for three days during which time he received IV antibiotics that were continued for seven days after hospital release. This particular player also took oral antibiotics three times a day for seven days upon hospital release. The athlete returned to play after 10 days of inactivity with the infected area protected by a non-adherent pad and secured with elastic tape. The athlete with the anterior knee infection underwent a knee bursectomy and was equipped with a wound vacuum for one month post-bursectomy to prevent fluid accumulation and further infection. After surgery, he received two weeks of IV antibiotics. For two months following surgery, the knee was sterilized and re-packed with gauze three times per week. Presently, the wound has not completely healed and the physician has not cleared the athlete for participation. The seven athletes who have returned to practice have shown no signs of staphylococcus skin infection recurrence. Unique aspects of this case were the numerous players infected within a brief time period and the resulting surgical procedures undergone by 3 of the 8 athletes. Healthy individuals typically carry staphylococcus bacteria on their skin, in their nose, and/or in their mouth. Infection may result when the bacteria enter the body through injured skin, through frequent physical contact, or through shared clothing or equipment. Knowledge concerning the etiology, signs, symptoms, and treatment of staphylococcus infection, will assist clinicians in taking proper precautions to prevent widespread infection and expedite athletes return to play.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-87.

Multiple Organ Laceration In A Collegiate Football Player

CL Maslanka ¹, M Myers ¹

Abstract

A 20-year-old wide receiver took a direct blow, from an opponent's helmet, to the upper left quadrant of his thorax/abdomen. Upon completion of the play the athlete attempted to stand and return to the sideline, when then attempt failed, athletic training personnel were called onto the field. The athlete presented with dyspnea and severe pain in the upper left quadrant and ribs when reached for on field evaluation. The athlete was able to stand with assistance and walk off the field. The athlete had no prior history or complaints of rib or abdominal injury.Sideline assessment began to rule out the possibilities of pneumothorax, rib fracture or an organ injury. There was pain on palpation of ribs 10, 11 and 12 as well as pain with breathing and generalized left quadrant discomfort. Normal, bilateral pulmonary auscultations were heard; ruling out pneumothroax. A positive anterior-posterior rib compression test validated the possibility of a rib fracture or contusion. There was no rebound tenderness or rigidity of the abdomen. The athlete was monitored on the sideline for several minutes when he began to complain of increased pain in the abdomen and back as well as nausea and an unexplainable pain in his left shoulder. The presence of Kehr's sign, a signal of splenic rupture, caused immediate transportation of the athlete to the Emergency Room for further care and evaluation.At the hospital, the athlete received an abdominal CT scan to determine the extent of the possible damage. The test revealed lacerations to the spleen and left kidney. The degree of the laceration was not severe enough to warrant surgery, but rather conservative management. The athlete was admitted to the intensive care unit for continued observation and was release after 2 days. As part of the conservative management the athlete is to remain inactive for 4–6 weeks, and return for follow up tests and CT scan at 4 weeks post injury date. Complete recovery and return to participation in intercollegiate football is expected. A flak jacket will be required for additional protection of the area. This case is very unique for the fact that multiple organ lacerations are most commonly seen in motor vehicle accidents or other traumatic events. Single organ blunt abdominal trauma caused by contact sports make up 10 % of all abdominal injuries. Half of those cases are renal; the other half is comprised of spleen and liver injuries. A case with multiple organ lacerations caused by a contact sport mechanism is very infrequent and uncommon.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-87.

Lateral Tibial Plateau Fracture In A Collegiate Football Player

EC Wolf ¹, SE Garvey ¹, BA Krause ¹

Abstract

A 19-year-old NCAA Division I football player was playing recreational basketball and sustained an injury to his right knee. The athlete landed on an extended leg after completing a lay-up and suffered an acute trauma. The patient denied a rotational mechanism to the knee. Immediately there was profuse swelling about the entire knee joint. He recalls hearing a “pop” and experienced intense acute pain, rated at 9/10. He had decreased range of motion and was unable to bear weight. He had a medical history of Osgood Schlatter disease, genu recurvatum (−10°) and an MCL injury 3 years prior. The purpose of this case report is to discuss the findings in a unique injury uncommon to a football athlete and the subsequent accelerated progression of his rehabilitation. The athlete presented with 2+ effusion in the knee and joint stiffness. He had pain to the lateral joint line and lateral tibial plateau. There was slight parapatellar point tenderness. Knee ROM was −5 degrees of extension to 90 degrees of flexion. Valgus stress test revealed some joint laxity; however, mainly due to depression into the lateral tibia plateau. A distal neurovascular exam reveals a 2+ dorsalis pedis pulse with intact sensation throughout the distribution. The differential diagnosis included meniscal tear, MCL sprain, ACL rupture, PCL rupture, patellar subluxation, and tibial plateau fracture. Plain X-rays revealed a comminuted lateral tibial plateau fracture. CT scans confirmed a comminuted lateral tibial plateau fracture. A venous doppler was performed 1 week post surgery to rule out deep vein thrombosis because of persistent calf swelling and tenderness. Results of this test showed normal flow and augmented flow in the femoral vein, superficial femoral vein, and popliteal vein. The veins were compressible and showed no evidence of a popliteal cyst. The final diagnosis of this injury was a comminuted lateral tibial plateau fracture. Surgeries were performed 24 hours post injury. An arthroscopically guided reduction and debridement preceded an open reduction internal fixation (ORIF) of the right tibial plateau fracture with allograft bone graft. The athlete was immediately placed into a brace locked at 30°. Athlete was non-weight bearing for six weeks. ROM exercises using the CPM machine and swimming rehabilitation began immediately and lasted until he was cleared to begin weight-bearing exercises. The athlete was clinically and radiographically cleared to begin weight-bearing exercises at 6 weeks. At this point progressive resistive exercises were introduced to the rehabilitation. At 10 weeks status post surgery he was biking and walking without a limp. At this stage a rehabilitation plan focusing on functional drills and a running progression was initiated to progress the patient to unrestricted football activities. At 14 weeks he was allowed to participate unrestricted in football practice. The incidence of tibial plateau fractures is not well documented. Of the millions of fractures that occur in the United States each year, approximately 1% are estimated to involve the tibial plateau. This case is important to share because it highlights a predisposing factor that may predispose athletes to lateral tibial plateau fractures. The athlete's genu recurvatum was thought to be a primary predisposing factor. Furthermore, the progressive nature of this athlete's return should be noted and attributed to preinjury strength capabilities and high level of motivation. This case further demonstrates the need for close attention to anatomical and biomechanical variances of our athletes.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-88.

Unusual Diagnosis Of Trench Foot In A Collegiate Softball Player

JL Gleisner ¹, RE Stewart ¹, JA Manners ¹

Abstract

The purpose of this study is to examine a weather-related danger in athletics, other than a high heat index or freezing temperatures. The athlete in this case is a 20 year-old white, female, softball centerfielder who reported to the athletic training room in May 2003 complaining of swollen, painful feet. The team had played in a four day tournament, where it had been approximately 50 degrees Fahrenheit and raining all weekend. During the tournament, the athlete reported to the athletic trainer with one red spot on the plantar surface of her left foot. She claimed she felt as if she had stepped on something causing a puncture wound. The athletic trainer padded this area with a donut and the spot resolved within three days with no further incidence. The following weekend, similar playing conditions were experienced at another four day tournament. On the last day of the tournament, the athlete reported to the athletic trainer with point tender spots on the plantar aspect of her foot. At this time, there were two tender red spots, about three centimeters in diameter, on the plantar aspect of the right foot. The foot was padded with foam donuts around the painful sites and the athlete finished the tournament with no further problems. The following day, the athlete presented to the athletic training room with an increase in pain, swelling and redness throughout the entire right foot. There were raised, red spots surrounded by a reddish-purple discoloration, on the plantar aspect of the foot; the sites appeared to be approximately the same size as the previous day, though they had increased in number. The foot was extremely point tender, especially directly on the bumps and the athlete was placed on crutches, non-weight bearing, for ambulation. The athlete was referred to the on-campus Student Health Services Center in order to rule out cellulitis. Student Health Services diagnosed this athlete with a case of cellulitis and referred her to the Peninsula Regional Medical Center Emergency Room due to an uncertainty regarding appropriate antibiotics to prescribe. Although the athlete did present with a low-grade fever, there was no red streaking in the area, which would be indicative of an infection, such as cellulitis. The evaluation of the ER Physician consisted purely of visual examination with a final diagnosis of trench foot in the right foot. Trench foot is a systemic infection characterized by swollen, discolored feet that are extremely painful. If untreated, this condition can lead to gangrene of the lower extremity. Ideally, trench foot is treated by keeping the feet warm and dry at all times; periodic massage is also recommended to keep the blood flowing through the foot to ward off gangrene. The athlete in this case study was instructed to wear two pairs of socks at a time to keep the foot warm. Instructions were also given to change shoes and socks whenever they became wet. The ER physician prescribed the antibiotic Cethalexin (500 mg, four times per day) and also advised her to take Ibuprofen (400 mg every four hours). After two days of antibiotic treatment, the swelling in the athlete's foot had dissipated and the pain had diminished. The physician cleared her for play with instructions to continue the full course of the antibiotics. Two weeks after the initial appearance of the reddened spots, the right foot continued to appear pinkish in color while the spots remained a darker pigment. Normal color returned approximately five weeks post initial treatment. This athlete completed the season with no further complications and experienced no residual effects from the disease. This case is unique due to the fact that trench foot is a condition that is not frequently diagnosed in the athletic population. Even so, the sports medicine community should be aware of this condition due to the frequent playing conditions of cold, wet weather. The importance of keeping the extremities dry and warm needs to be stressed more often when talking to the athletes about overall health and hygiene. Key Words: cellulitis, trench foot

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-88.

Incidence Of Skin Trauma Associated With Participation In Off-Season Intercollegiate Football And Soccer

RE Daubenmire ¹, MS Anderson ¹, JW Beam ¹

Abstract

Participation in intercollegiate athletics involves risk of injury. Previous research focusing on the incidence, injury rate, and etiology of musculoskeletal conditions has demonstrated that off-season (spring) football and soccer often are associated with the highest rates of trauma among intercollegiate sports. However, little information on the incidence of skin trauma associated with these particular sports is available in the literature. The purpose of this study was to identify the frequency and injury rate of skin trauma among NCAA Division I football and soccer student-athletes. For this study, a reportable wound was defined as: occurring in an athletic-related activity (physical conditioning, practice, or competition), requiring attention by an athletic trainer or physician, and resulting either in restriction or non-restriction of student-athlete participation following the injury. All injuries were evaluated and treated by a certified athletic trainer and/or physician. Data were collected during off-season (spring) football and soccer seasons. Descriptive statistics were calculated for the data. An average of 65 student-athletes (age: 20.8 + 2.2) participated in football, totaling 771 practice athlete exposures (AE). A total of 14 practice injuries were documented, for an injury rate (IR) of 18.15 injuries/1000 AE. The most common wounds were lacerations (42.9%) and blisters (28.6%). The most common mechanisms of injury were rubbing/friction (50.0%), irregular tearing (21.4%), and smooth tearing (21.4%) through contact with equipment (50.0%) and another student-athlete (28.6%). The most frequently injured body locations were the upper arm (21.4%), toes (14.3%), and shoulder (14.3%). An average of 24 male student-athletes (age: 19.6 + 1.1) participated in soccer, totaling 617 practice athlete exposures (AE). A total of 10 practice injuries were documented, for an injury rate (IR) of 16.20 injuries/1000 AE. The most common wounds were blisters (50.0%) and lacerations (40.0%). The most common mechanism of injury was rubbing/friction (90.0%) through contact with the ground (40.0%) and clothing (40.0%). The most frequently injured body locations were the foot (50.0%) and lower leg (30.0%). Since skin trauma typically does not result in time loss from athletic participation, data on incidence rates are not collected and often deemed inconsequential in epidemiological investigations. This study began the identification of the types and mechanisms of skin trauma associated with intercollegiate participation in off-season football and soccer. The high incidence of skin trauma reported in this study warrants further investigation and the etiology of skin trauma in other intercollegiate sports needs to be evaluated.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-89.

The Relationship Between Eyes-Closed And Eyes Open Postural Control Measures Assessed During Five And Fifteen Second Trials

AL Bauer ¹, TA Evans ¹, RB Williams ¹, RJ Lund ¹

Abstract

Static, single leg, eyes-closed postural control is one variable commonly used to assess functional ankle instability. However, while recovering from a lateral ankle sprain, this task is difficult to complete for extended durations and is therefore excluded from clinical assessment. It is uncertain how eyes-closed trials of shorter duration correlate with longer trials. The purpose of our project was to assess the relationship between eyes-closed and eyes-open postural control measures held for five and fifteen seconds. We used a randomized, repeated measures design. Thirty young adults, 15 with functionally stable ankles and 15 with functionally unstable ankles, volunteered as subjects. Subjects underwent three randomly ordered balance tests: 1) 15 seconds eyes-open (open), 2) 15 second eyes-closed (closed15), and 3) 5 seconds eyes-closed (closed5). Subjects performed three trials of each balance test in a single leg stance on an AMTI Accusway force plate (ATMI Inc., Watertown, MA) interfaced with a computer utilizing SWAYWIN software (ATMI Inc., Watertown, MA). Center of pressure excursion velocity was the dependent measure of postural control. Data were analyzed through a repeated measures ANOVA and Pearson product moment correlations. The ANOVA indicated a significant trial (open vs. closed5 vs. closed15) effect across both groups (F = 95.23, p < 0.0001). Post hoc analysis with Bonferroni correction revealed significant differences between open and closed5 (t = −12.130, p < 0.0001) and open and closed15 (t = −12.367, p < 0.0001). There was no significant difference between closed5 and closed15 (t = −2.078, p = 0.047). For the unstable group, we found high positive correlations between open and closed5 (r = 0.86, p < .001), open and closed15 (r = 0.76, p <.001) and between closed5 and closed15 (r =0.85, p <.001). For the stable group, although significant, no correlation exceeded r = 0.43, indicating weak to moderate relationships. Our results suggest that single leg eyes-closed balance trials, held for five seconds, may be of sufficient duration to assess postural control in athletes with functional ankle instability. Tests of five-second duration may allow the assessment of eyes-closed postural control while recovering from lateral ankle sprain. Our subjects were not however, recovering from a recent ankle sprain, therefore it is still uncertain how variations in test duration affect post-injury postural control measures.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-89.

Treatment Of A Second Degree Hamstring Strain With Active Release Technique

KM Frankenfield ¹, JE Fitzpatrick ¹, BA Krause ¹

Abstract

An 18 year old African-American division I-AA running back presented to the athletic trainer with right hamstring pain after sprinting during a spring football practice. The athlete stated feeling a “pop” and pain in right hamstring. His chief complaints were sharp, stabbing pain and overall discomfort. The patient had no previous history of a hamstring injury. Upon initial on-field examination, the athlete described sharp, stabbing pain immediately after feeling a pop and was not able to bear weight on the affected side. No obvious deformity was observed or palpated. He had point tenderness at the right semimembranosus muscle belly with associated muscle spasm. Knee flexion was within normal limits with pain, he was unable to perform hip extension against gravity and hip flexion range of motion was decreased secondary to pain. Strength testing revealed 3/5 with knee flexion and 1/5 with hip extension. The athlete was unable to bear full weight on the affected side. Differential diagnosis included partial tear of the right semimembranosus, fascia rupture and avulsion fracture at ischial tuberosity. Radiographic examinations were all negative. Isokinetic testing at one month post injury resulted in a quadriceps/hamstring ratio of 0.48. There was a significant deficit on the effected side as speed increased while testing. The athlete was diagnosed with a partial tear of his right semimembranosus. The athlete received a medical red shirt the following football season as he was unable to participate at that level. The athlete was placed on a traditional treatment and rehabilitation protocol. The treatments included ultrasound, electrical stimulation, and soft tissue massage. Rehabilitation included functional rehabilitation, stretching, and isokinetic strengthening. After full rehabilitation and returning to spring football, cumulative trauma and repetitive micro trauma plagued the athlete's performance. He continued to undergo conventional treatment and rehabilitation. When minimal improvements in function and pain occurred, the athletic trainer referred the athlete to a chiropractor to receive active release treatment (ART), approximately one year after the hamstring injury. When referred, the patient stated to be only 80% of his preinjury competitive level. He presented with increased tension and scar tissue in the right semimembranosus and adductor magnus. Scar tissue limited full tissue lengthening and deviated normal range of motion. ART was used to alleviate pain and increase function associated with musculoskeletal injuries. The concept was based on the pathological accumulation of adhesions within the structure. The technique involved locating the scar tissue, applying pressure with active repeated lengthening of the structure. The clinician was able to locate the structures involved by activity and palpation of spasm, altered texture and movement. The involved tissue was then placed in a shortened position. Pressure was applied distal to the injured area and tension placed on the tissues parallel to the fibers. If excessive pressure placed perpendicular to the fibers tissue damage may occur. While the manual pressure is maintained the tissue was actively or in some cases passively moved in the opposite direction of the pull of the muscle causing a lengthening of the tissue. The clinical outcome was a break-up of adhesions that was causing the decrease in function abilities. After three treatments of ART the athlete reports no limitations, equal hamstring flexibility when compared bilaterally. The athlete returned to participation at 100% by the end of spring football drills.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-90.

Gender Differences In Knee Position During Three Functional Tasks

EN Bennett ¹, LC Olmsted ¹, J Hertel ¹

Abstract

Anterior cruciate ligament (ACL) injuries are a common occurrence in athletics and there is a 2–8 times higher incidence of ACL injuries in females. The majority of ACL injuries are non-contact in nature, and may occur while landing from a jump. Gender differences in landing and jumping may exist. The purpose of this study was to examine gender differences in knee flexion angle and dynamic valgus during three functional activities. Thirty physically active college students (15 females, 15 males) with no history of lower extremity injury participated in this study. Subjects had a mean age of 20.9 ± 2.4 years, mean height of 172 ± 11.3 cm, and a mean weight of 68.5 + 14.2 kg. Subjects performed single leg squat, step down task, and maximum vertical jump tasks with their dominant leg. All trials were recorded with a video camera in the frontal and sagittal planes. A software program was used to perform a two-dimensional kinematic analysis to calculate joint angles at the knee. For each dependent variable, a one way ANOVA was calculated to determine if gender differences existed. Alpha level was set a priori at .05. For the single leg squat, females demonstrated significantly more knee flexion (F_1,28=5.16, p=.03) and more hip flexion (F_1,28=5.55, p=.03) than males. Females reached an average of 87.2° of knee flexion while males averaged 81.5°. Females reached an average of 58.6° of hip flexion while males averaged 48.9°. For the step down task females demonstrated significantly more knee flexion than males (F_1,28=3.97, p=.05). Females reached an average of 53.7° of knee flexion while males reached an average of 47.9°. Females also demonstrated greater knee valgus for this task (F_1,28=8.51, p=.007). Females had an average of 17.5° of knee valgus and males had an average of 10.3°. For the vertical jump, there were no significant differences between genders for knee flexion, hip flexion or knee valgus angle. Our main finding was a difference between genders in knee flexion and hip flexion angles (single leg squat) and knee flexion and knee valgus angles (step down task). Females tend to perform some functional activities with a more flexed hip and valgus positioned knee which may be a predisposition for ACL injury. A more flexed hip and valgus positioned knee may place the hamstrings on a stretch making them less efficient at preventing anterior shear forces on the tibia.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-90.

The Effects Of Myofascial Release And Static Stretching On Hamstring Flexibility

SP Shultz ¹, DA Padua ¹, MA Petschauer ¹, CJ Hirth ¹

Abstract

Restricted range of motion (ROM) may predispose an individual to musculo-skeletal injury. Previous research has demonstrated static stretching to be an effective method of increasing ROM. Myofascial release is an alternative method to address restricted ROM. However, there is limited research investigating the effects of myofascial release. Therefore, the purpose of this study was to compare the effects of myofascial release and static stretching on hamstring flexibility. Twenty-nine subjects participated in this study. In order to participate in this study subjects met the following criteria: 1) no history of lower back pain or hamstring injury within the past 6-months and 2) at least a 15° knee extension deficit during the active knee extension (AKE) test. Subjects were randomly assigned to one of three groups: 1) control, 2) static stretching (SS), and 3) myofascial release (MR). The SS and MR groups underwent three training sessions per week over a four week period. The SS group performed a standing stretching protocol by flexing their hip to 90° while maintaining full knee extension and an anterior pelvic tilt. This position was held for 30 seconds and repeated four times per training session. The MR group lay prone and actively extended the involved knee while pressure was constantly applied to the midbelly of the hamstring. This was performed four times per training session. The control group did not participate in any formal flexibility training. Hamstring flexibility was assessed using the AKE test. During the AKE test subjects lay prone with their hip and knee flexed to 90°. The subject then actively extended their knee until they noted resistance and maintained this position. The angle formed between the femur and lower leg was then measured using a goniometer. Hamstring flexibility was measured prior to training and on a weekly basis over the 4-week training period. A mixed-model repeated measures ANOVA was used to compare the groups (3 levels: control, SS, MR) across the treatment sessions (5 levels: baseline, week 1, week 2, week 3, week 4). Hamstring flexibility significantly increased from Week 1 to Week 4 for the MR and SS groups (P < 0.05). There was no significant difference between the MR and SS groups across the four test sessions. Based on data collected during this study, both SS and MR are effective methods to increase hamstring flexibility.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-90–S-91.

Retroperitoneal Hematoma Of An Unknown Cause In A Football Player

MK Smith ¹, ME Jemionek ¹, PM Lamboni ¹

Abstract

A 20-year-old Division III male football wide receiver reported to the Athletic Training Room with pain in the lower left quadrant of his back. The athlete found it difficult to find a comfortable position due to a sharp pain which increased when movement was initiated. He also reported discomfort while sleeping. The athlete had no previous medical history of low back pain or injury. He believed that the pain had been caused by a slip at football practice the day before. He had no known trauma to the area during the week. The initial evaluation revealed unspecified low back pain that seemed to be located over the erector spinae muscles on the left side. Upon palpation there was increased point tenderness over the erector. There was no discoloration or swelling. The athlete had pain with extension and end range pain with flexion. The athlete was treated with ice massage on stretch for en erector strain. That night, the pain in his back intensified, becoming extremely point tender. He also experienced pain in his abdomen. That night, the athlete reported to the emergency room where conventional X-rays were taken which revealed an irregular mass in the abdominal area. A CT scan was ordered which found a large retroperitoneal hematoma around the area of the left kidney. The athlete again denied any trauma or recent illness. The athlete was placed on strict bed rest until another CT scan was conducted. A complete blood workup was ordered to investigate whether an illness that may have been the cause. The athlete underwent another CT scan which revealed the mass to have shrunk in size, but still very apparent. The athlete was released from the hospital and placed on best rest with absolutely no activity. The athlete was recently sent for a biopsy, the results of which are still anticipated. A retroperitoneal hematoma is not commonly seen among athletes, especially when there is no known traumatic injury. The athlete had presented to the Athletic Training Room with symptoms associated with a low back strain. The ultimate condition of a retroperitoneal hematoma without a causation factor is certainly a difficult clinical diagnosis. The proliferation of significant back pain with the associated abdominal pain was the trigger that sent this athlete to the hospital.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-91.

Dry And Moist Heat Application And The Subsequent Rise In Tissue Temperatures

C Wood ¹, KL Knight ¹

Abstract

Since the advent of the hydrocollator heat pack in the 1950s, the use of the traditional electrical hot pad has diminished. We could find no scientific comparison of the effects of the two types, so we performed this study. The design was a 2×3 factorial with gender and type of hot pack (hydrocollator, electrical, and electrical over wet towel) as independent variables. Dependent variables were surface and 2 cm deep intramuscular temperature. Twelve males & twelve females were assigned to one of six treatment orders according to a Balanced Latin Square. Temperatures were measured with type-T thermocouples & an Isothermex in the posterior calf, 10 cm distal to the popliteal space for 20 minutes during modality application and for 10 min following application. Results showed no gender differences, so the data was combined. There was no difference between conditions for skin (∼31°C) and muscle (∼36°C) temperatures before heat application. After 20 minutes of application, the electric heat over a wet towel, electrical, and hydrocollator pack resulted in temperature increase of ∼5.6°C, ∼9.4°C, and ∼10°C, respectively, and intramuscular temperature increases of ∼.02°C, ∼.7°C, and ∼.95°C, respectively. At the end of the 20 minute application, the electrical hot pad was gradually continuing to increase skin and muscle temperature whereas the hydrocollator heat pack had peaked and was decreasing. Even though these two heat treatments were different at 20 minutes, the difference was only .6 of a degree. It is probable that if a few more minutes were added to the treatment, the electrical heat would be as warm as the hydrocollator pack. Electrical hot pads are less expensive than hydrocollator units, do not require rewarming between uses, and are tolerated better than hydrocollator packs. Electric heat pads appear to be a viable alternative to hydrocollator packs for heat applications in excess of 20 minutes.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-91.

In Vivo Exploration Of Glenohumeral Pericapsular Temperature During Cryotherapy

AJ Strang ¹, MA Merrick ¹

Abstract

Cryotherapy protocols have been largely based on data from the thigh, knee, and ankle but there are inadequate data describing pericapsular temperature at the shoulder during cryotherapy. The purpose of this study was to describe in vivo pericapsular temperature at the glenohumeral joint. Secondary purposes were to compare the temperature response during shoulder cryotherapy to existing data at the ankle and thigh and to adapt an existing temperature measurement technique for the ankle to the glenohumeral joint. Following IRB approval, a repeated measures design was used with 12 volunteer subjects (8 female, 4 male, age = 21.5±0.5y) without history of pathology to the shoulder. The sole independent variable was treatment (control & cryotherapy). Data were analyzed using a paired samples t-test. The cryotherapy treatment, intended to mimic post-activity prophylactic cryotherapy, consisted of a 30 minute application of a standard icebag to the posterior shoulder using a 6-inch double-length elastic bandage applied in a common spica pattern. Baseline temperature data obtained immediately prior to the icebag application were used as the control. Temperature data were collected at 30 second intervals using implantable thermocouples inserted using sterile hypodermic needles and then interfaced to a portable datalogger. Baseline periarticular temperature of the posterior shoulder was 36.0±0.27°C and is similar to temperatures reported at the thigh and warmer than those reported for the ankle Post-cryotherapy temperature was 21.5±1.32°C and was statistically different than baseline temperature (p.=0.000). The magnitude of temperature change we observed at the shoulder (−14.5°C) is less than has been reported at the ankle (−18°C) but is greater than is typically reported at the thigh (−7°C). The adaptation to the glenohumeral joint of a previously described technique for measuring periarticular temperature at the ankle is important because it opens an entirely new area of cryotherapy research. A second important implication is that baseline temperatures at the glenohumeral joint are similar to those at the thigh, however the post-cryotherapy temperature is somewhat different than those reported at the thigh. This is important because data driven cryotherapy protocols are largely based on thigh data. Similarly, pericapsular temperatures during cryotherapy at the shoulder appear to differ from those at the ankle as well. The differences are most likely attributable to differing muscle mass in the different body segments. It appears that the use of cryotherapy protocols that do not take into account the differing temperature response of different body segments may be inappropriate.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-92.

Erythema Annulare Following An Ice Application

GC Dover ¹, PA Borsa ¹, D McDonald ¹

Abstract

A male college student (age=19 yrs, height=185 cm, mass=79.8 kg, body fat%= 9.7, triceps skin fold=9mm) arrived at the research laboratory to participate in a cryotherapy research study. The University's institutional review board approved the study protocol prior to data collection. The subject read and signed the consent form, which included contra-indications for a cryotherapy application. The subject stated that he used cryotherapy for a previous knee injury. After collecting demographic data, a temperature probe was taped just distal to the tip of the acromion of the dominant shoulder. A flexible surface temperature probe with a contact surface area of 0.8 cm² was used to measure the skin surface temperature. The probe was connected to a thermometer with a range of 0° C to 100° C and an accuracy 0.1° C. An ice bag weighing 1 kg with the air removed was applied to the shoulder using an elastic bandage. After the first 10-minutes of the 30-minute application, the subject complained of a headache, being “woozy”, and feeling dehydrated, but offered to continue with the application. Immediately following the principal investigator (PI) noticed the skin surface temperature change was significantly different than the skin surface temperature changes of previous subjects. The subjects' skin surface temperature was significantly higher at several time increments compared to 6 other male subjects with similar demographics that underwent the same treatment (age=22.6 ±1.5 yrs, height = 179.5 ± 4.9cm, mass = 78.4 ± 5.6kg, % body fat = 10.6 ±1.8, skin fold (triceps in mm) = 10.3 ± 4.9). After 30 minutes of cryotherapy, the ice bag was removed and the skin surface of the subject was examined. The PI noticed that the subject had developed a significant wheal formation and discoloration under the ice bag. The subject was then removed from participating in the rest of the study. When questioned by the PI about the reaction, the subject reported that he suffered from a similar reaction following the previous cryotherapy application on his right knee. The subject was not aware that his reaction to cold treatment was abnormal and felt that the benefit from cryotherapy out weighed the discomfort during the previous session. The wheal formation and all signs and symptoms completely resolved within 48 hours. The subject had a reaction to a cryotherapy application that is consistent with cold urticaria. Other possible conditions may include pressure urticaria, allergy urticaria, or hereditary angio-edema. Signs and symptoms of cold urticaria include wheal formation, erythema, itching, and systemic signs and symptoms including headache, nausea, wheezing, shortness of breath, and in severe cases syncope and cardiac arrest. The whealing in response to the cold stimulus is associated with degranulation of mast cells with the concomitant release of histamine and other inflammatory factors. Exactly how the dermal mast cells are triggered to release histamine and other mediators are unclear. The subject in the present case most likely suffered from acquired cold urticaria, and was unaware of any other medical conditions or diseases that may have triggered the reaction. The skin surface temperature readings in the current report were higher compared to the normal data around 10 minutes following ice application. The time at which the change occurred is similar to a previous study which measured blood levels of histamine in response to cold urticaria. The timing of the increase of skin surface temperature of the subject closely matched the timing of the increase of the histamine release as seen in the previous study. Monitoring skin surface temperature change in a clinical research setting may be an easy and useful means to monitor histamine release because skin surface temperature measurements are non invasive compared to blood draws. Clinicians should be aware of cold urticaria when using cryotherapy and the potential serious consequences. From a preventative standpoint the patient needs to be made aware of the condition for future reference. Cold urticaria can be uncomfortable on the skin, very uncomfortable in the throat (similar reaction in the throat if drinking cold liquid), and potentially life threatening if placed in a cold aquatic environment. Patients who display signs and symptoms of cold urticaria should be advised to refrain from certain aquatic activities.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-92–S-93.

Transient Electrical Changes Immediately Following Muscle Trauma

JB Driban ¹, CB Swanik ¹, KA Swanik ¹, KC Huxel ¹, E Balasubramanian ¹

Abstract

In sports medicine, electrical stimulation (ES) is commonly applied to acute muscular injuries without quantitative data on the tissue's electrochemical response to trauma, inflammation and the healing process. Measuring muscle tissue's transient electrical properties (TEPs) is one method of evaluating the efficacy of electrical stimulation. The purpose of this study was to examine the TEPs of muscle tissue immediately following trauma and determine whether a physiological basis for ES on acute muscle injuries exists. A time-series design was used to evaluate the electrical potentials (volts) and current intensity (pico-amperes) of 11 participants (ages 45–80) undergoing total hip arthoplasty. The measurement locations were 1) pre-incision skin surface after anesthesia 2) post skin incision on muscle surface and 3) muscle tissue, post muscle incision. All measurements were performed three times using a Keithley Electrometer 610B with a low-noise coaxial lead and a solid gel ground electrode. Two 1-way (location) ANOVAs with repeated measures on location were performed to determine differences in the electrical potentials and current intensity between test locations. A Tukey HSD was used for post hoc analysis. When compared to the pre-incision value, the electrical potentials were significantly (p=0.05) more negative following skin incision and skin + muscle incision (p=0.002); (Pre-incision = .012±.146 V, Skin Incision = −1.27±1.47 V, Skin + Muscle = −1.90±1.53 V]. Current intensity also changed significantly following the skin incision (p=0.048) and SM incision (p=0.001); (Pre-incision = 1.31±3.44 pA, Skin Incision = −12.39±15.62 pA, Skin + Muscle = −20.47±10.58 pA). These observations indicate that as the incision was deepened; the electrical potentials and current intensity became increasingly more negative, suggesting that an increase in the amount of soft tissue trauma produced greater changes in the TEPs. However, no greater change in the TEPs occurred following isolated skeletal muscle tissue trauma when compared to skin trauma alone. The negative acute changes represent an electrochemical event marking the onset of the inflammatory response. Based on these results, the recent use of ES to promote healing following acute muscular injuries has no physiological basis. High variability in the electrochemical response was present at all levels suggesting individualized reactions to trauma. Therefore, if ES is expected to promote optimal healing conditions, personalized ES parameters will be required. Furthermore, the effect of ES on the TEPs of acutely injured muscle tissue is unclear. Additional research needs to determine if the existing protocols are promoting or disrupting an optimal healing environment. Supported by a grant from the NATA Research & Education Foundation Osternig Master's Grant Program.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-93.

Comparison Of Tissue Heating Using 3 Mhz Ultrasound With Methyl NicotinateVersus Aquasonic Gel

DT Gulick ¹

Abstract

The purpose of this research was to determine if T-prep®, a 1% methyl nicotinate preparation, used in conjunction with 3 MHz ultrasound increased the temperature of soft tissue more than ultrasound with Aquasonic gel. Thirty healthy participants (21–40 years of age) completed this IRB approved study. In the prone position, a 26-gauge, 4 cm thermistor was inserted 2.5 cm deep in the posterior calf. An OmniSound Unit was used to administer a 3 MHz treatment at 1.0 w/cm² in a 6 cm²-defined area with a 2-cm2 sound head. Temperature measurements were taken every 30 seconds for 15 minutes. On one calf 5 cc of Aquasonic gel was used as the coupling medium and on the other 5 cc of T-Prep® gel was used. A repeated measures ANOVA was used to detect a significant difference over time but no significant difference was found between the coupling mediums. The T-Prep® gel produced a 1.8°C temperature increase while the Aquasonic gel resulted in a 1.5°C increase over 15 minutes. Despite starting at a lower average temperature, it was at the 6-minute mark of ultrasound application that the tissue temperature with the T-Prep gel began to diverge from that of the aquasonic gel. The results of this study revealed that T-Prep was as effective as Aquasonic gel in increasing tissue temperature 2.5 cm deep with 3 MHz ultrasound. Given that there are numerous conducting mediums that have been shown to limit the transmission of ultrasonic waves, T-Prep may be an excellent option to Aquasonic gel. Further research on the depth of heating with T-Prep® gel would be appropriate.Key words: methyl nicotinate, ultrasound, tissue heating

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-93.

The Thermacare Heatwrap^® Increases Skin And Paraspinal Muscle Temperature Greater Than The Curaheat Patch^®

DO Draper ¹, CA Trowbridge ¹

Abstract

Numerous heating products claiming to relieve pain by increasing tissue temperature are available. To date, ThermaCare HeatWraps^® are the only products we have tested that have shown significant increases in intramuscular temperature. Recently the CuraHeat Patch^® was marketed containing the same ingredients as ThermaCare^® (iron, charcoal, etc.) but has a smaller area of heat coverage. The package insert states that it should not come in contact with skin, hence it is to be worn over clothing. The purpose of this study was to compare the effectiveness of the ThermaCare HeatWrap^® and the CuraHeat Patch^® on increasing skin and paraspinal muscle temperature and heat perception. Subjects were 18 college-age volunteers. Independent variable was treatment and baseline temperature the covariate. Dependent variables were temperature change and heat perception. The Isothermex recorded temperatures to the nearest ± 0.1°C every 1 minute. Subjects rated heat perception using a 10 cm visual analog scale (VAS). For all variables, differences from baseline were calculated and analyzed. Maximum temperatures and those at 15-minute intervals for 150 minutes were analyzed for both treatments with ANCOVAs. Heat perception was analyzed with ANOVAs. To measure paraspinal muscle temperature one thermocouple monofilament was inserted 1.5 cm deep at the L3 level using a catheter. Another thermocouple was used to measure skin temperature. During the CuraHeat^® testing, subjects wore a Hanes cotton T-shirt that was carefully pulled over the thermocouple before applying the patch; whereas, the ThermaCare^® was tested directly on the skin according to manufacturers specifications. The mean maximum intramuscular and skin temperature increases for the ThermaCare^® were 1.81°C ± 0.10 and 4.28 ± 0.32°C respectively. The mean maximum intramuscular and skin temperature increases for the CuraHeat^® were 1.33 ± 0.10°C and 3.01 ± 0.32°C respectively. The ThermaCare^® produced significantly higher temperature readings in the muscle (F_2,29 = 30.09, p < 0.0001) and skin (F_2,29 = 26.29, p < 0.0001). The VAS data showed that ThermaCare^® provided the greatest heat sensation at all time points (F_1,10 > 6.82 p < 0.01). The ThermaCare HeatWrap^® feels warmer than the CuraHeat Patch^® and is more effective at increasing skin and intramuscular temperature. Although our subjects remained still, we believe that the heating capabilities of the CuraHeat Patch^® would be further reduced during activity because the patch would migrate with the clothing it is placed over. Conversely, the ThermaCare HeatWrap^® will stay in place because it is not placed on clothing.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-93–S-94.

Moist Heat Pack Re-Warming Following 10, 20, And 30 Min Applications

AK Morris ¹, KL Knight ¹, DO Draper ¹, E Durrant ¹

Abstract

Our objective was to quantify the rewarming time of a moist silicate-gel heat pack following application on a human quadriceps muscle for various times; and to quantify the temperature increase of the quadriceps at 2 cm into the muscle depth during treatment times and 10 min post treatment. Our experimental design was a 3×3 factorial with repeated measures. The independent variable was application duration (10, 20, or 30 min) and time (pre-treatment, end of treatment, and 10 min post treatment). Four dependent variables included: heat pack temperature, thigh intramuscular temperature during treatment, skin surface temperature during treatment, and water temperature changes in the storage unit. Subjects were 12 college students free from muscle injury or circulatory defects for the past 6 months. Surface, intramuscular, heat pack, and water temperatures were measured pretreatment, end of treatment, and 10 min post treatment. Surface and intramuscular temperatures were measured on/in the same quadriceps muscle. Heat pack and water temperatures were measured on the top and bottom of the heat pack and water storage unit. Repeated measures MANOVA and ANOVA's and Tukey-Kramer multiple range tests were used to determine significant differences between conditions and time. There was no difference in pretreatment temperature between conditions for any of the four variables. Subjects' surface temperature increased 9° to 12°C during application. The 10 min condition heated the skin the most, and the 30 min condition heated the least. Following application, subjects cooled 4° to 7°C, but there was no difference between conditions. Intramuscular temperature was not different between conditions, but each condition increased significantly during application. Heat pack temperature decreased approximately 15°C in the 10 min treatment, 20°C in the 20 min treatment, and 26°C in the 30 treatment. After 10 min of rewarming, the heat packs were within 2°C of pretreatment temperature following the 10 and 20 min applications and within 3.5°C following the 30 min application. Clinicians should allow 15 to 20 min for heat packs to rewarm, and those in busy athletic training clinics should adopt a specific rotation system for their heat packs to insure that each is adequately rewarmed prior to subsequent use.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-94.

Exercise Prior To Cooling Reduces Quadriceps Cooling Time

BC Long ¹, ML Cordova ¹, JB Brucker ¹, TJ Demchak ¹, MB Stone ¹

Abstract

The purpose of this study was to investigate the efficacy of a standard ice bag treatment on post-exercise quadriceps muscle temperature. Six physically active male volunteers (age = 26.0±3.2 yrs, ht = 181.6±2.4 cm, mass = 92.9±9.1 kg, anterior mid-thigh skinfold 25.4±2.7 mm) consented to participate. Subjects were excluded if they reported any circulatory, vascular, blood diseases, as well as hypersensitivity to cold. A 2×3 fully repeated measures design with depth (1cm and 2cm below adipose tissue) and condition (exercise treatment followed by an ice bag treatment, exercise treatment followed by no ice bag treatment, and no exercise treatment followed by ice treatment) was used. The dependent variables were the length of time it took to: (1) return the rectus femoris musculature back to resting temperature; and (2) to cool the rectus femoris musculature to 10°C below resting temperature. Each subject was assigned to a condition order according to a balanced Latin Square, and tested at the same time of day (within an hour) on 3 different days separated by 48 hrs. Each day consisted of inserting catheter-assisted thermocouples to 1 cm & 2 cm below subcutaneous fat layer directly into the right anterior mid-thigh. Muscle temperature was monitored every 15 s beginning 5 min prior and throughout each treatment condition. The exercise treatments consisted of riding a cycle ergometer for 30 min at 70 - 80% of their age predicted max heart rate, while the no exercise condition consisted of laying supine on a treatment table. The ice bag treatments consisted of 1 kg crushed ice applied with compression within 42 – 48 mm Hg, or no treatment. Not surprisingly, a crushed ice bag cooled both exercised muscle depths back to resting temperature faster (P<0.001). Moreover, the superficial muscle tissue cooled faster back to baseline when ice was not applied (P=0.001), and to 10°C below resting whether it was exercised or not (P<0.001). What was interesting, however, was that quadriceps temperature at both depths cooled back to resting temperature within the same amount of time when ice was applied (P=0.38). Additionally, exercise reduced the time it took both depths to cool to 10°C below resting temperature (P=0.02). It may be concluded that the body's heightened thermoregulatory system response, as a result of exercise, greatly enhances the efficacy of a cold modality.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-95.

Land-BasedAndAquatic-Based Plyometric Training Programs Has No Effects On Balance

JK Kelly ¹, MG Miller ¹, MD Ricard ¹, DM Ritenour ¹

Abstract

Balance can be referred to as one of the most important components of athletic ability. The goal of the athlete is to have excellent balance in order to perform better in their given sport. Following an injury, athletic trainers incorporate single and double leg exercises into rehabilitation programs to enhance balance. Plyometrics is a training technique used by athletes in all types of sports to increase strength, power, and speed and often used during rehabilitation programs both on land and in water. Previous research speculated that aquatic plyometrics may have affected balance, however, there is no data to support this claim. The purpose of this study was to compare aquatic plyometrics to land plyometrics and its effects on dynamic and static balance. Thirty-six healthy subjects (17 males, 19 females) were randomly assigned to one of three groups (control, land, aquatic). Subjects were not currently performing any plyometric activities prior to study. Each subject performed three trials of a static (single leg stance) and a dynamic (standing on a dyna disc®) balance tests on a Kistler force plate pre and post-training. Both land and aquatic plyometric groups met for training twice a week for seven weeks. Training took approximately 15–20 minutes per session and all exercises were for lower body. Ground reaction forces (GRF) were sampled at 100Hz for 10 s while subjects performed static and dynamic balance trails. Center of pressure (COP) was calculated from the GRF. Three trial averages of the following dependent variables were calculated from COP: radial area, x range, y range, xy area, distance, mean Vx, mean Vy, mean X frequency, mean Y frequency. A (3 × 2) factorial repeated measures ANOVA was used to identify differences in the three trial averages of each dependent variable by training group (control, land, or aquatic) and time (pre, post). No significant interactions between training group and time were found suggesting that plyometric training did not affect the measures of static and dynamic balance used in this study. While plyometric training does enhance strength and power production it does not appear to affect static or dynamic balance. Further investigation is warranted to explore the effects of land-based and aquatic-based training programs and balance.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-95.

Kinematics And Metabolic Cost Of Forward Vs Backward Treadmill Walking

MA Mastrangelo ¹, CB Swanik ¹, M Santiago ¹, K Swanik ¹

Abstract

Backward walking (BW) is frequently used during lower extremity rehabilitation. Limited data, however, exists on the kinematics and physiologic cost of this treatment technique. This information is important to ensure the health and wellbeing of patients with musculoskeletal and/or cardiovascular disorders who engage in BW during rehabilitation. The purpose of this study was to compare total body kinematics and metabolic cost associated with forward walking (FW) versus BW at a constant speed on a level and elevated treadmill. Twenty healthy individuals (11 female, 9 male) volunteered for the study (mean age (yrs), female = 24.09, male = 28.78, height (cm), female = 162.56, male = 179.49, mass (kg), female = 58.92, male = 80.35). After a familiarization session, 3 consecutive 3 min trials of FW or BW were conducted at 0.76 m·s⁻¹ (1.7 mph) with elevations of 0, 5, and 10% grades. The locomotion mode was counterbalanced. Kinematic and metabolic data were collected simultaneously and analyzed with a mixed-model ANOVA for repeated-measures design. Differences between the two modes of walking were evaluated at the three different treadmill elevations. Trunk and neck range of motion (ROM) were significantly (p<.05) greater during FW vs. BW at 5 and 10% elevations. Trunk ROM [mean (SD)] was 39.50° (10.97°) for FW and 32.12° (8.53°) for BW at 5% elevation. At 10% elevation the trunk ROM was 42.98° (6.92°) for FW and 27.53° (7.62°) for BW. Neck ROM [mean (SD)] was 22.65° (6.48°) for FW and 17.05° (5.99°) for BW at 5%; and at 10% FW was 26.53° (10.96°) and BW 21.87° (17.29°). Knee ROM was significantly greater (p<.05) during FW than BW at level and 5% elevation. Mean (SD) knee ROM was 65.36° (4.40°) for FW and 49.08° (9.43°) for BW at 0%, and at 5% was 66.25° (23.81°) for FW and 57.18° (23.86°) for BW. No other signif icant kinematic differences were found. Oxygen uptake (VO₂) during BW was significantly greater (p<.05) than FW at both 0 and 5% elevation. VO₂ [mean (SD)] values at 0% for BW were 9.83 (2.16) ml·kg⁻¹·min compared to 7.54 (1.05) ml·kg⁻¹·min for FW. At 5%, BW VO₂ was 11.45 (2.54) ml·kg⁻¹·min compared to 9.85 (1.09) ml·kg⁻¹·min for FW. The kinematic differences of BW compared to FW may negatively alter body mechanics for some patients and should be considered before implementing this exercise technique in rehabilitation. Furthermore, since the physiologic demand (VO₂) is greater during BW, patient vital signs should be monitored in some populations to prevent increased health risk while performing BW during rehabilitation.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-95–S-96.

Lower Extremity Muscle Activation During Upright And Recumbent Cycling

AP McMurtrey ¹, RF Reiser II ¹

Abstract

Cycling is a common rehabilitation and training modality that now offers a choice between the upright and recumbent positions. However, it is unclear if the two cycling modalities are interchangeable. Also, since the anthropometry of men and women are slightly different, gender could play a role in any differences. Therefore, the goal of this study was to examine muscle activation levels across different power levels and gender between upright and recumbent cycling. After obtaining university-approved informed consent, 15 healthy men (age = 21.7 ± 1.0 yrs; height = 179.4 ± 6.8 cm; mass = 76.4 ± 11.8 kg) and 15 women (age = 21.7 ± 1.0 yrs; height = 166.8 ± 4.7 cm; mass = 60.0 ± 5.4 kg) with recumbent cycling experience participated. The angle between the hip, bottom bracket, and horizontal was 75° for upright and 0° for the recumbent. The backrest of the recumbent was set 50° above horizontal to match the average 130° angle observed between the mid-torso, hip and bottom bracket in the upright position. Max hip-to-pedal distance was set to 105% of standing hip-to-floor distance in each position. In randomized order, each subject pedaled at 60 rpm steady state at 60, 90 and 120 W against the same resistance unit for both upright and recumbent positions. Bipolar surface electrodes, sampled at 1200 Hz, were on the tibialis anterior (TA), gastrocnemius (GAS), soleus (SOL), vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF), hamstrings (HAM) and gluteus maximus (GMX). Normalized average muscle activity across 3 pedal revolutions for each condition were compared with a 2 by 6 ANOVA (p<0.05). There was significant interaction between gender and condition for the RF (p<0.001) and SOL (p=0.009). The women had higher levels of RF & SOL activity than the men in the upright positions, but lower activity levels in the recumbent positions compared to the men. In general, muscle activity increased with power level, though the increases were not always significant at each level of power increase (TA, SOL (men only), GAS, and RF (men only). Additionally, muscle activation levels were different at the same levels of power between upright and recumbent positions for several muscles (SOL (men only), GAS, RF (men only), and GMX). In light of these differences between men and women as well as the upright and recumbent cycling conditions, consideration of cycling modality should be included when choosing between upright and recumbent cycling.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-96.

Dynamical Systems Analyses Of Pelvis, Thigh And Shank Coordination During Lateral Step Down Exercise In Females

BL Riemann ¹, JM Drouin ¹, SE Wedekind ¹

Abstract

Lateral step-down exercise is a frequently used rehabilitation exercise. To date, other than a few isolated studies considering isolated joint kinematics, few studies have investigated the coordination between pelvis and segments comprising the lower extremity. Therefore, the purpose of this investigation was to use a dynamical systems approach to determine the coordination between the pelvis, thigh and shank during lateral step-downs. Thirty-one Division I female athletes (mass=67.6±7.7kg, height=168.4±8.1cm, age=19.7±1.4yrs) completed lateral step-downs while three-dimensional kinematics of the pelvis, thigh and shank were collected. The step-down height was adjusted to 20% of leg length and the pace constrained to a standardized speed (.5Hz). The angular displacements and velocities of the three body segments with respect to the frontal (FP) and sagittal (SP) planes were time normalized across ten trials. Phase plots were created for each segment, followed by calculation of phase angles (PA) for each trial. Relative phase angles (RPA) were then computed between adjacent segments. The RPA for the ten cycles were then ensemble averaged and the mean absolute relative phase (MARP) and deviation phase (DP) calculated. MARP quantifies whether two adjacent segments move in-phase or out-of phase, while DP provides indication of the pattern's stability. Separate two-factor repeated measures analysis of variance (ANOVA) were conducted on the MARP and DP values. Further, correlational analyses were conducted between the DP values for each segment/plane combination. Results of qualitative analyses of the ensemble averaged RPA revealed several distinct patterns within each segment/plane combination, several participants displayed unique patterns. The ANOVAs for both MARP and DP revealed significant segment by plane interactions (P<.001). Tukey post hoc analyses of the MARP revealed the sagittal plane thigh-shank coordination (9.4±5.6) significantly more in-phase compared to all other plane/segment combinations (SP pelvis-thigh=47.6±17.8, FP pelvis-thigh=42.4±21.6, FP thigh-shank=54.6±22.8). For DP, post hoc analyses revealed SP thigh-shank (10.0±8.1) < SP pelvis-thigh (29.1±14.7) <FP pelvis-thigh (49.4±18.1) <FP thigh-shank (58.1±12.7). Correlational analyses revealed a significant relationship (r=.53) between the FP thigh-shank and FP pelvis-thigh DP. Collectively, these results suggest the SP thigh-shank coordination exhibits a stable, in-phase pattern. Surprisingly, the SP pelvis-thigh coordination and stability were significantly less than SP thigh-shank coordination. FP coordination was revealed to be relatively unstable compared to SP. Finally, with the exception of the significant FP relationship, stability of the coordination patterns appeared to be independent of each other. Future research is recommended to consider the underlying causes contributing to the differing patterns and stability.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-96–S-97.

The Comparative Effects Of Four-Week Core Stabilization and Balance-Training Programs On Semidynamic And Dynamic Balance

AB Piegaro ¹, MA Sandrey ¹, ML Erickson ¹, S Zizzi ¹

Abstract

The purpose of our study was to determine the effects of four-week core stabilization and balance-training programs on semidynamic and dynamic balance. Our study included 39 subjects (12 men; 27 women) from a college population (21.87 ± 2.26 years; 169.91 ± 9.07 cm; 72.16 ±13.29 kg). Subjects were free of lower and upper extremity pathology and neurological, vestibular, and visual disorders within the past six months. They were randomly assigned to one of four groups (control group, core stabilization group, balance group, or combined core stabilization/balance group) using stratified randomization for gender and activity. The design of our study was a 2 × 4 factorial design. The independent variables were time (pre-test and post-test) and group (control group, core stabilization group, balance group, and combined core stabilization/balance group). The dependent variables were semidynamic and dynamic balance. Subjects in the three experimental groups performed their training program two days per week for four-weeks. The core stabilization-training group performed a beginner's core stabilization training-program on a foam roller. The balance-training group performed thirteen balance exercises while maintaining a single leg stance on a fixed surface, tilt board, and wobble board with eyes open and closed. The combined core stabilization/balance-training group performed both the core stabilization and balance-training programs. Subjects in the control group did not perform any of the training programs and continued their normal activities of daily living. The Biodex Stability System Test (semidynamic balance) and Star Excursion Balance Test (dynamic balance) were used for pre-test and post-test. To determine if there were differences between groups for the pre-test data, a one-way ANOVA was conducted for the Biodex Stability System Test (BSST) and Star Excursion Balance Test (SEBT). Three, two-way repeated measures ANOVAs were conducted for the BSST. Eight, two-way repeated measures ANOVAs were conducted for the SEBT. To control for Type I error using a Bonferroni Correction Factor for the two-way repeated measures ANOVAs, the level of significance was set at P = .0166 (.05/3) for BSST and P = .00625 (.05/8) for SEBT. There was no significant difference for pre-test data for the BSST between groups (P ≥ .05). There was a significant difference for pre-test data for the SEBT between groups for anterolateral excursion (F_3,38 = 4.260, P = .011). There were no significant differences for the BSST (P ≥ .0166). There were significant differences for time (medial, posterior, and lateral excursions) and time X group (posteromedial and anterolateral excursions) for the SEBT (P ≤ .0062). A combined core stabilization/balance-training program may be used to improve semidynamic balance, whereas a core stabilization-training program or balance-training program could be used to improve dynamic balance. Supported by a grant from the NATA Research & Education Foundation Osternig Master's Grant Program.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-97.

Standing And Supine Hamstring Stretches Are Equally Effective

LC Decoster ¹, RL Scanlon ¹, KD Horn ¹, J Cleland ¹

Abstract

The purpose of this study was to evaluate the relative effectiveness of standing and supine hamstring stretching in increasing hamstring flexibility as measured by increasing knee range of motion. A convenience sample of 29 healthy subjects (22 females, 7 males, age 25.9±6.13) with tight hamstrings (≥ 25° from full knee extension with the hip in 90° flexion) volunteered to participate in this study. Supine active knee extension was used to assess knee range of motion. All subjects performed one stretching method on each leg three days per week for three weeks (3 × 30 seconds per leg per session). The stretch performed on each leg was randomly assigned using a computer-generated number table. The supine stretch involved placing the stretching leg on a wall with the opposite leg and trunk flat on the floor. The standing stretch involved placing the heel on a plinth with the pelvis tilted anteriorly and the spine held erect. Stretching sessions were supervised; no warm-up activities preceded any measurement or stretching session. Measurements were taken before and following the three-week stretching phase by the same investigator, who was blind to leg assignment. A two-way mixed design ANOVA and Tukey's HSD post hoc tests were used to analyze data. The leg stretched in the supine position improved from 139.45° (±9.68°)) to 147.52° (±8.25°)). The leg stretched in standing improved from 138.31° (±10.68°)) to 147.66° (±10.28°)). The mean change score for the supine stretching legs was 8.1° (± 8.4°, 95% confidence interval 4.7–11.4°) and for the standing stretching legs was 9.4° (± 9.7, 95% confidence interval 6–12.8°). Analysis revealed a significant main effect for the within group factor, time (df=1, F= 53.5, p<0.025) but not between groups (df=1, F= .030, p = .585). Post hoc analysis revealed a significant difference (p<0.05) from pre- to post-test measurements for both stretching methods, but no significant difference (p>0.05) between the supine and standing group measurements. A different group participated in two measurement sessions to assess intratester reliability (ICC (3,1) =.899). This study suggests that standing and supine hamstring stretches are comparably effective. There was no significant difference in change score between the standing and supine hamstring stretches. With proper instruction and supervision, both stretches can be effective and may be used interchangeably. However because the supine stretch does not require specific pelvic positioning, and therefore requires less instruction and supervision, it may be more effective for independent programs.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-97.

The Effects Of Aquatic Balance Training On Core Stability In Individuals With Chronically Unstable Ankles

MT Moore ¹, RA Hess ¹

Abstract

Core stability programs are an important method of prevention for many athletic injuries. Some individuals have difficulty attaining the proper position to engage the deeper abdominal muscles due to postural muscular imbalances, weight constraints, or possible physical anomalies. The purpose of this study was to determine if aquatic conditioning concentrating on ankle balance and proprioception was effective in increasing balance and core stability in a training group compared with a control group. Subjects were twenty-two (29 unstable ankles) college student volunteers with no current medical problems, or dizziness. Unstable ankles were determined by subjective measures with individuals reporting instability and history repeated sprains and at least one grade 3 ankle sprain (minimum one week of inability to bear weight or crutch walking). Subjects were randomly assigned to one of two groups; training (Swim-Ex) or control. Control group subjects were asked to not participate in balance training or core stabilization exercise specifically, but not to abstain from general exercise. The model 700T multidepth Swim-Ex, set at a current of approximately 2.5mph with approximately mid-sternal height water, was used as the training medium. All subjects were pre and post-tested using the Biodex Balance System measuring dynamic stability (DS) and limits of stability (LOS), the plyoback for time to touch down (static balance), and the degree to which (level), as well as the time to hold a modified plank position. The training group went through a six-week, 18 session, training regimen consisting of three exercises following the principle of progressive resistance exercise which included a single leg stance, ball toss, and jumping all with eyes closed. A repeated-measures ANOVA and Pearson Correlation were used to analyze the data. No group differences were reported for DS (Lambda (1,27)=1.157, P >.05), or LOS (Lambda (1,19)=1.27, P =.274). However, an overall increase in LOS scores regardless of group was interpreted as a learning effect. A significant group difference was reported on the plyoback (Lambda(1,27)=7.05 P =.013) indicating an improvement in time to touch down (increased static balance) of the training group. Also, while no differences were reported in the plank level obtained as most subjects were already able to obtain a full plank (Lambda(1,19).794 P =.384), additional analysis revealed that training group subjects reported a significant increase in the time holding the position (Lambda(1,19)= 4.390, P =.05) indicating that the training group's core stability, particularly endurance of the core musculature increased. Future research should concentrate on acute rehabilitation of the unstable ankle. Also the core stability findings could indicate additional venues for core stability improvement, and should be further explored.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-98.

Short-Term Effects Of Grade 1 And 2 Joint Mobilizations At The Pathological Lumbar Spine

S Hanrahan ¹, BL Van Lunen ¹, M Tamburello ¹, ML Walker ¹

Abstract

Numerous clinicians support the utilization of joint mobilizations (JM) of the spine as an integral part of the treatment process, however the immediate effects of JM have not been fully examined. The purpose of this study was to examine the short-term effects of grades I and II posteroanterior joint mobilizations at the pathological lumbar spine on subject pain, range of motion (ROM), and muscle force (lumbar extension). All subjects were determined to have sustained mechanical dysfunction of the lumbar spine of less than 48 hours as assessed through a standardized evaluation. Nineteen male (age = 20.3 yrs; ht = 185.4 cm; wt = 92.0 kg) collegiate athletes were randomly assigned to two treatment groups. The JM treatment group (n=9) received JM, ice, and stretching while the non-JM treatment group (n=10) received ice and stretching only. The JM were performed at 3 consecutive lumbar segments surrounding the area of greatest discomfort. An oscillatory grade I treatment was administered for 30 seconds with a 30 second resting period, followed by grade II JM, for a total of six 30-second treatments. Data collection consisted of a (1) pain assessment through the McGill Pain Questionnaire (MPQ), and a visual analog scale (VAS) in lumbar neutral, flexion, and extension, (2) ROM at the L1 and L5 spinous processes, and (3) muscle force with a hand-held dynamometer during maximal voluntary contraction. Data collection was taken pre-, immediate post-, and 24 hours post treatment. Analyses of variance were conducted to determine differences in the dependent measures over time. All subjects had decreased values for the MPQ over time (p=.000)and a significant decrease (p=.048) in pain was found for the sensory subset of the MPQ for the JM group. Muscle force increased over time (p = .000), however the JM group had a significantly higher increase (p=.001) over time. There was a significant decrease in pain for the VAS in lumbar flexion (p=.012) and extension (p=.001), and a significant difference in pain level between groups at the 24 hour post-test with the JM group being significantly lower. There were no significant differences between the groups for ROM. JM's for pain are a cost-effective and useful component in the immediate treatment of acute mechanical dysfunctions in the lumbar spine. Further research should investigate other segments of the spine and the utilization of this technique over a longer period of time.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-98.

Comparisons Of Land And Aquatic Balance Training

AE Roth ¹, MG Miller ¹, MD Ricard ¹, D Ritenour ¹, BL Chapman ¹

Abstract

Aquatic therapy has clinical relevance for exercise, sport performance, and rehabilitation, yet studies on balance training in the aquatic environment are limited. The purpose of this study is to compare the effects of a land-based and aquatic-based balance training programs on both static and dynamic balance. Twenty-four subjects were randomly placed into one of three groups: land (n=10), aquatic (n=8), and control (n=6). Baseline balance measurements were taken using testing positions comprised from the Balance Error Scoring System (BESS). Subjects performed a series of 2 stances (single leg stance and tandem stance) on the surface of a force platform and on a piece of medium density foam placed on the platform. Training sessions were conducted 3 times per week for 4 weeks. The exercises performed were exactly the same regardless of the environment, land or water, using a balance board and an 8-inch step. Subjects placed in the control group performed only the balance measurements at the designated times and were asked to carry out normal daily activities during the duration of the testing and training period. A repeated measures analysis of variance (ANOVA) was employed to compare land and water based training on static and dynamic balance. The independent variables are the training groups, the water and land environments, and time (before and after training). The dependent variables were x range, y range, and radial area measured using a force platform. Vertical, anterior-posterior, and medial-lateral ground reaction forces were measured for each subject performing the tests using a Kistler 9421 A11 force plate and a Kistler 9861A 8-channel amplifier interfaced to a Gateway computer. The force data was sampled at 100Hz for each of the tests. Results indicated that there were no significant interactions between the groups and conditions that suggest that balance training increases regardless of training environment. Future studies should examine alternative methods to assess balance performance including postural sway and the BESS system.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-98–S-99.

Effects Of Myofascial Release And Static Stretching On Active Range Of Motion And Muscle Activity

EC McClellan ¹, DA Padua ¹, KM Guskiewicz ¹, WE Prentice ¹, CJ Hirth ¹

Abstract

Static stretching is an effective method to increase range of motion (ROM). Myofascial release is an alternative method that may also improve range of motion. However, research has not investigated the effects of myofascial release on range of motion. In addition to limiting range of motion, tight muscles may influence the activation of antagonist muscles through reciprocal inhibition. Unfortunately, research has not examined if antagonist muscle activation is influenced following stretching of tight muscles. Therefore, the purpose of this study was to compare the effects of static stretching and myofascial release to the hip flexors on hip extension ROM. A secondary purpose was to determine if static stretch and myofascial release influence gluteus maximus activation during treadmill running. Subjects were assigned to either a static stretching treatment group (SS) (n=20) or small ball myofascial release treatment group (SB) (n=20). In order to be included in this study subjects demonstrated at least a 10° hip extension deficit as measured by the modified Thomas test. Prior to treatment, we assessed hip extension ROM using a goniometer. We also measured muscle activation amplitude using surface electromyography of the gluteus maximus during treadmill running. Following the initial test session, subjects underwent either the SS or SB treatment protocol. Immediately following we re-assessed hip extension ROM and gluteus maximus activation. Hip extension ROM was also assessed 15-minutes after the treatment protocol. Separate mixed model repeated measures ANOVA were performed. Each analysis involved “group” as the between subject factor and “time” as the within subjects factor. Statistical analyses demonstrated a significant group-by-time interaction (P=0.025) for hip extension ROM. Post hoc analysis revealed that compared to pre-treatment measures both the SB and SS group demonstrated significantly greater hip extension ROM at immediately following treatment and at 15-minutes post-treatment. In comparison to the SB group, hip extension ROM measures were significantly greater for the SS group at the post-treatment and 15-minute post-treatment time periods. There was no significant difference between groups prior to treatment. Gluteus maximus activation demonstrated no significant main effect for time, nor group-by-time interaction (P>.05). Based on these findings it appears that both a single SS and SB treatment are able to improve ROM. However, the SS treatment results in greater ROM gains. Neither the SS nor SB treatments improve antagonist activation of the gluteus maximus during treadmill running. Future research should investigate the effects of multiple treatments on these variables.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-99.

High Load Eccentric Exercise For Treatment Of Chronic Achilles Tendinopathy: A Systematic Review

JM Hootman ¹

Abstract

The long-term prognosis of patients with conservatively treated Achilles tendino-pathy is generally good and acceptable, however, almost one-third require surgery and over half have chronic side-to-side strength and functional deficits. The purpose of this study is to conduct a systematic review of published randomized, controlled clinical trials (RCT) or quasi-experimetnal studies using high load eccentric exercise interventions to treat chronic Achilles tendinopathy. A systematic search of CINAHL, Medline, PubMed and EMBASE bibliographic databases using the terms Achilles, tendonitis, tendinosis, tendinopathy and exercise resulted in 381 publications published between 1982 and 2003. Five papers met all inclusion criteria (RCT or quasi-experimental design, English language publication, and utilized an eccentric exercise intervention in at least one group). One additional study was identified through checking reference lists of selected papers. Data on subject demographics, inclusion/exclusion criteria, methods, intervention protocol, and outcomes were abstracted on a standard form. The primary outcomes assessed were pain during activity per Visual Analog Scale (VAS) and the proportion of subjects reporting return to full activity. Of the 6 included studies, 2 were randomized, controlled trials and 4 were quasi-experimental study designs. Studies averaged 51 subjects (range 9–108). All subjects had clinically evident chronic Achilles tendon pain and thickening (2–6 cm level) for at least 3 months. Most cases were also confirmed via ultrasonography. Eccentric training programs were similar in all studies. Comparison groups had varying levels of intervention including no treatment, usual care including concentric exercise and surgical intervention. Four studies measured pain on activity at baseline and follow-up and 3 studies reported return to activity status. On average, the patients in the eccentric exercise groups had significantly reduced pain (mean 87.4% decrease; range 80.5–95%) and more returned to full activity (85.3%; range 74.0–100%) over 12 weeks. Patients in the comparison groups showed less decrease in pain over the treatment period (average 78.1%; range 70.4–85.7%) and fewer returned to full activity (44.7%; range 36–53.3%). These results suggest that high load eccentric exercise programs are effective for chronic, mid-portion Achilles tendinopathy in terms of pain reduction and return to full activity. However, due to the small sample sizes, lack of RCTs and short follow-up periods among published studies, additional research in this area is needed.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-99.

Immediate Effects Of Static Stretching And Muscle Energy Technique On Hamstring Flexibility

AE Harris ¹, HA Worthy ¹, BL Van Lunen ¹, G Vairo ¹

Abstract

Various stretching techniques for increasing hamstring flexibility exist, however the use of a muscle energy technique has not yet been critically examined. The purpose of this study was to determine the immediate effects of two types of stretching protocols on hamstring flexibility as measured by anterior superior iliac spine (ASIS) height difference and knee angle. Thirty-six (18 females, 18 males; age = 20.33 ± 1.43 yrs, ht = 176.10 ± 15.24 cm, mass = 78.21 ± 25.44 kg) collegiate athletes who lacked 20 degrees of knee extension from vertical and who had not sustained an injury to the lower extremity in the past six months participated in this study. Subjects completed all treatment conditions (one per session) in a counterbalanced order on three separate occasions. Independent variables included treatment (muscle energy, static stretching, and control) and test (pre and post). The dependent variables included ASIS height difference and knee angle. ASIS height difference was measured by placing a metal ruler with a carpenter's level at the inferior aspect of the lower ASIS and a standard tape measure was used to determine the height difference. The limb with the higher ASIS was used for the treatment protocols. Knee angle was measured using a goniometer with 12-inch arm extensions, and flexibility was recorded as the number of degrees from complete knee extension. All measurements were taken immediately before and after completion of treatment protocols. During the static stretching protocol, the subject stood erect with the calcaneal aspect of the foot on an elevated surface while flexing forward from the hip and the arms reaching forward. The stretch was held for 30 seconds and repeated 5 times with a 10 second rest period. The muscle energy technique consisted of having the subject prone with their knee flexed to 90 degrees and resisting movement into knee extension. The procedure was completed 5 times for 7 seconds with a 10 second rest between trials. Two 3 × 2 ANOVA's were used for data analyses. ASIS height difference decreased (p=.003) and knee angle increased (p=.000) from pre to post tests for the two treatment sessions, but no significant difference was found between these two treatment sessions. No differences were found for the control condition. Static stretching and muscle energy techniques are both effective methods to increase immediate hamstring flexibility. Future research should further examine muscle energy techniques and the long-term effects on hamstring flexibility.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-99–S-100.

Days Of Rest Between Stretching Bouts Increases Hamstring Flexibility

TL McCallister ¹, EM Korthals ¹, JB Brucker ¹, ML Cordova ¹, CL Stemmans ¹

Abstract

The purpose of this investigation was to examine the effect of days of rest between stretching bouts on hamstring flexibility gains. Thirty volunteers (m = 19, f = 11, age = 21.5±1.93 yrs, mass = 79.2±18.19 kg, ht = 175.1±8.83 cm) not involved in a regular stretching program, with no low back or left lower extremity pathology 12 months prior to the study were recruited. A 3×6 factorial design with repeated measures on the last factor (session) guided this study. The independent variables were rest period (24hr, 48hr, and 96hr) and session (1–6). The dependent variable was angle of inclination of a passive straight leg raise as measured by a digital inclinometer. Subjects were familiarized, and randomly assigned to a group where they were measured and stretched for 5 sessions. The 6^th session consisted of taking a measurement only. Subjects exercised at a “somewhat hard” rating of perceived exertion for 10 min on a stationary bicycle prior to 3 flexibility measures. These measures were taken immediately after the cycling and securing the subject to a plinth in the supine position. The endpoint of the measure was determined when the subject stated hamstring tension. Following the measures, they performed 3, 30-s stand-and-reach stretches separated by 15s rest intervals. The right foot Fick angle was approximately 25°, while the left foot was placed on a 0.76m high table against the modified sit and reach box so that the calf musculature relaxed. Passive measurements did not indicate any change in flexibility (F_5,135 = 1.53, P = 0.19), nor was there any indication that the additional rest between bouts affected the measures (F_2,27 = 1.89, P = 0.17). Because we believed the cycling, the short rest interval between the cycling and measurements, or the stretching and measuring protocol differences may have affected these results, we performed a similar analysis using the 1^st stand-and-reach measure of each stretching session. Similar to the first analysis, the rest periods did not affect (F_2,27 = 0.95, P = 0.40) flexibility. However, improvements in flexibility were noted (F_4,108 = 21.49, P<0.0001), which was different from the previous analysis. Moreover, the longer rest periods seemed to enhance the stand-and-reach measures (4.2, 4.8, 6.9cm, respectively). In conclusion, it does not seem necessary to stretch daily because gains in flexibility may be a learned effect that takes place over time. Furthermore, the intensity of exercise immediately prior to measurement may alter a person's sensation to tissue elongation.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-100.

Positional Evaluation Of Range Of Motion, Strength And Power In Division I University Football Players

JB Bonacci ¹, I Jones ¹, B Brown ¹, R Ferguson ¹, D Decker ¹

Abstract

Athleticism for team sports can be difficult to define. Different positions in football may require unique qualities and characteristics often not associated with the sport as a whole. Prior research in our lab demonstrated unique differences in power output according to position (Daniel, Brown et al., 1980). Other studies have demonstrated a moderate predictive relationship between body fat and power. There is a dearth of information on range of motion at several upper and lower body joints and its relationship to the qualities (i.e., strength and power) most associated with football playing ability. The present study investigated differences among several measures of strength, speed, range of motion (ROM), height, weight and body fat among 53 university football players classified into four positional categories (lineman-LM, linebackers-LB, backs-B, and quarterbacks/receivers-QR). Relationships among the performance variables were also investigated by position. Measures of flexibility included shoulder lift, hamstring ROM, lumbar ROM (double inclinometer technique), plantar and dorsal flexion ROM (both lying and seated positions). Strength assessments included max bench press, max squat, back, and abdominal (using new technique, ABMED, Brown et al, 2003). Power was evaluated using power clean, vertical jump and standing long jump. Speed was assessed from a 20 and 40 yard dash. As an entire team there were moderate to high negative correlations between body fat and power (r = −.76), but no relationship of percent body fat to strength. The ROM of various body joints did not demonstrate significant interrelationships. Upper and lower body strength (squat vs. bench) was poorly associated. Analyzed by position, a different pattern emerges. Between lineman and backs greater ROM in plantar and dorsal flexion of the ankle was associated with lower speeds and power output (r =.79). Greater abdominal strength was associated with enhanced power (r =.67) in LB, but the reverse occurred in B (r = −.68). There were significant differences in ankle ROM analyzed by position. LM showed significantly greater plantar flexion ROM of the left ankle than linebackers and backs. QR demonstrated greater dorsal flexion of the left ankle compared to the other three positions. Body fat percentages for LM were twice that of the other positions (19% vs. 9%). Standing long jump was significantly lower in LM than the other three positions, and LM were slower than backs and QR. In summary, ROM is specific to each joint with little carryover to either other body segments or the same bilateral joint. Greater power output, but not strength is associated with reduced percent body fat. The role that flexibility plays at different joints may need to be considered by position rather than as an entire team.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-100–S-101.

Isokinetic Bench Press As A Criterion Measure Of Upper Body Power In NCAA Division I College Football Player Starters And Non-Starters

JK Nakasuji ¹, IF Kimura ¹, RK Hetzler ¹, A Nichols ¹, M LaBotz ¹

Abstract

The purpose of this study was to investigate whether the isokinetic bench press could discriminate football-playing ability and to correlate the isokinetic bench press with other commonly used football upper and lower body power tests. National Collegiate Athletic Association (NCAA) Division I collegiate football players aged 18–26 years were divided into two groups by player ability: starters (Group 2) and non-starters (Group 1). On separate days, subjects performed the vertical jump, 40-yard dash, one-repetition maximum (RM) bench press and isokinetic bench press at 60, 180 and 300°/s. Pearson Correlation Coefficient analysis revealed significant correlations among all measures in the present study (height, weight, isokinetic peak force at 60°/s, 180°/s and 300°/s, vertical jump, 1-RM bench press and 40-yard dash). Height and weight negatively correlated with all measures, except the 40-yard dash, indicating that taller and/or heavier football players produced higher (slower) 40-yard dash times. Three 1 × 2 ANOVA's (p<0.05) were used to compare 40-yard dash times, vertical jump, and 1-RM bench press between starters and non-starters, respectively. Results indicated that 40-yard dash times of starters were significantly faster than non-starters, and no significant differences in vertical jump values and 1-RM bench press torque between starters and non-starters. Four x 2 ANOVA with repeated measures (p<0.05) analysis indicated that starters and non-starters produced significantly higher 1-RM bench press torque values than isokinetic bench press peak torque values at 60, 180, and 300°/s; higher isokinetic bench press peak torque values at 60°s/than at 180 and 300°/s; and no significant difference between isokinetic bench press peak torque values at 180 and 300°/s. Three x 2 ANOVA with repeated measures (p<0.05) analysis indicated that football starters produced significantly higher isokinetic bench press peak torque values at 60°/s than non-starters. Conclusion: isokinetic bench press can be used as an upper body power test to discriminate between starters and non-starters.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-101.

Relationships Between Nagi's Disablement Concepts In A Physically Active Population With Musculoskeletal Injuries

LI Vela ¹, CR Denegar ¹

Abstract

Musculoskeletal injury is a leading cause of disability. Disability is defined as “the inability or limitation in performing socially defined roles and tasks expected of an individual within a sociocultural and physical environment”. The disablement process has been defined and described by a number of researchers. A popular model by Nagi described a disablement process that consists of four sequential components: 1) pathology, 2) impairment, 3) functional limitations, and 4) disability. Nagi believed that disability is most directly affected by functional limitations, not impairments. Our purpose was to examine the relationships between the number of impairments, functional limitations and disabilities reported by physically active individuals with one symptomatic musculoskeletal injury. Data were extracted from a project directed towards developing an outcomes instrument for the physically active population. Seventeen physically active subjects (6men, 11women; age 20.9 ± 3.4 years; 9 lower extremity injuries, 8 upper extremity injuries) with a symptomatic musculoskeletal injury participated. Subjects completed a survey questionnaire that consisted of a comprehensive list of commonly observed problems separated under the appropriate components of the disablement process. Nagi's definition of each component was used to make the judgment about each term. The instrument was reviewed by a panel of 3 health care providers and 1 statistical consultant and revised for clarification prior to the study. Subjects were asked to select any and all problems that they felt were adversely affected by their injury. Pearson product moment correlation coefficients were calculated to estimate the relationships between the number of problems identified in each of the 3 components of the disablement model. Impairments and functional limitations were positively correlated (R² =.28, p=.015) as were functional limitations and disability (R² =.36, p=.006). A nonsignificant relationship between impairments and disability was observed (R² = .13, p>.05). When multiple regression was used to explain disability from impairments and functional limitations, 99% of the variance could be explained by functional limitations alone. While a large portion of variance in disability remains unexplained, these results are consistent with Nagi's hypothesis that disability is most directly affected by functional limitations. Our results are based upon the number of problems identified under the 3 categories and do not reflect the severity of the problem. Further investigation into these relationships, including analyses of severity, is clearly needed. Based on these results, however, the focus treatment of the physically active must go beyond addressing impairments to overcome the disabilities resulting from musculoskeletal injuries.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-101.

The Effects Of Arch Taping On Vertical Ground Reaction Forces Generated During A Drop Landing

MD Elizondo ¹, RP Wojciechowski ¹, ML Cordova ¹, TJ Demchak ¹, JR Storsved ¹

Abstract

Various arch taping techniques are used extensively in sports medicine in an attempt to provide mechanical support to the medial plantar surface of the foot. Although, this practice is widely used in athletes who participate in jumping and landing sports (i.e. basketball and volleyball), little is known if taping the arch in this manner affects impact forces imposed on the lower extremity during a sport-related task. Thus, the purpose of this study was to determine the effects of different arch taping techniques on vertical ground reaction forces produced while landing from a drop jump. Eighteen college-age males (age = 24.65 ± 2.4 yrs, ht = 175.75 ± 7.4 in, mass = 89.0 ± 20.69 kg, navicular drop = 11.3 ± 1.3 mm) who were free from any known musculoskeletal pathology 12 months prior to this study participated. Additionally, all subjects had functional pes planus as established by navicular drop assessment. A 1×3 repeated measures factorial design guided this study where the single within-subjects factor was arch taping technique with 3 levels: 1) low-dye 2) double-x method with forefoot support and 3) control. The ground reaction force data were digitally converted at 1000 Hz, appropriately processed, and analyzed into the following dependent measures: time to peak vertical ground reaction force (TPVGRF), peak vertical ground reaction force (PVGRF), and vertical ground reaction force slope (VGRFS). All subjects performed 8 drop jumps from a height of .28 meters under each arch taping condition in a counterbalanced order. The average of the 8 trials for each condition was used for statistical analysis. There was no overall multivariate effect of arch taping technique on the linear combination of vertical ground reaction force variables (Wilk's Lambda value = 0.946 (F_6,64 = .301, P= .934). When considered univariately, arch taping did not affect PVGRF (F_2,34 =.017, P=.983), TPVGRF (F_2,34 = .555, P=.704), and VGRFS (F_2,34) = .126, P=.882). The results of this study are promising in that application of 2 commonly used arch taping techniques does not stiffen the medial longitudinal arch in such a manner that vertical impact forces during a drop landing are significantly increased.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-102.

A Comparison Of Selected Arch Support Devices On Ground Reaction Forces Produced During A Drop Landing

BF Halwes ¹, ML Cordova ¹, TJ Demchak ¹, CD Ingersoll ¹

Abstract

The effect of different types of athletic shoes, foot orthoses and other arch support materials on lower extremity kinetics and ground reaction forces during walking and running gait has been documented; however, the potential effects of such devices on ground reaction forces during jump landings has not been extensively studied. Thus, the purpose of this study was to evaluate if over – the-counter arch supports, made of the same material, affect vertical and mediolateral ground reaction forces during a drop landing. Ten healthy males (age = 21.3±1.3 yrs, mass = 85.1±11.3 kg, ht = 185.3±11.4 cm) with no known lower extremity pathology 12 months prior to the study volunteered for this study. A 1 × 3 factorial guided this study where the single independent variable was treatment with 3 levels (no orthotic—control, standard insole, insole with arch support). Each subject performed 5 trials of a drop jump from a .6 meter height onto a force platform under the each orthotic condition in a balanced order. The ground reaction force data were digitally converted at 1000 Hz, appropriately processed, and analyzed into the following variables: peak vertical ground reaction force (PVGRF), vertical impulse (VI), time to peak vertical ground reaction force (TPVGRF), and average mediolateral ground reaction force (MLGRF). A 1× 3 repeated measures MANOVA and subsequent 1 × 3 repeated measures ANOVAs were used to statistically analyze the data (alpha level set at 0.05). An overall multivariate effect for arch support condition on the linear combination of vertical ground reaction force variables was found (Wilk's Lambda value = 0.363 (F_8,30 = 2.48, P= .03). When considered univariately, the data showed that for PVGRF the arch support condition increased compared to the control condition (P<0.05), but no differences existed between the standard insole and the control or between both orthotic conditions. For TPVGRF, an increase was observed for the arch support condition when compared to the insole condition (P<0.05), but no difference existed between the control condition and either orthotic condition. When evaluating VI, the arch support condition demonstrated an increase compared to the standard insole condition (P<0.05), but no differences existed between the control condition and both orthotic conditions. Additionally, MLGRF was not affected by orthotic condition when compared to the control condition (P>0.05). The results of this study suggest that selected arch support devices may aid in lower extremity vertical ground reaction force attenuation during a drop landing.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-102.

The Effects Of Patellofemoral Bracing On Quadriceps Activity During Open And Closed Kinetic Chain Exercise

MC Haskins ¹, ME Powers ¹, MD Tillman ¹, MB Horodyski ¹

Abstract

Patellofemoral pain syndrome is one of the most common musculoskeletal disorders seen in competitive and recreational athletics today. Rehabilitation generally consists of flexibility training, quadriceps strengthening, and patellofemoral bracing to assist patella alignment and tracking. While the effects of bracing on alignment have been investigated, research involving bracing and quadriceps activity is limited. It is possible that bracing might substitute for muscle activity as the patella tracks during knee extension, resulting in muscle weakness. Therefore, the purpose of this study was to assess the effects of patellofemoral bracing on quadriceps electromyographic (EMG) activity during open and closed kinetic chain exercises. Twenty-four subjects (age=23.0±2.7 yr., height=171.1±6.9 cm, mass=68.9±12.2 kg) without a history of knee injury participated in the study. Each subject reported to the research lab on two separate occasions. On the first occasion, the subjects were assessed for their one repetition maximum (1-RM) on the leg press (CKC) and knee extension (OKC) exercises. Forty-eight hours later, the subjects returned for the second session and were assessed for vastus medialis (VM) and vastus lateralis (VL) EMG activity while performing the same CKC and OKC exercises. EMG data were first collected while each subject performed one repetition of the OKC and CKC exercises using resistance equivalent to the previously determined 1-RM. Following a 5-min rest, subjects performed five repetitions of each exercise with and without a Patella Stabilizer Brace (Mueller Sports Medicine Inc., Prairie du Sac, Wisconsin) using 75% of the respective 1-RM. The order of conditions; CKC braced, CKC unbraced, OKC braced, and OKC unbraced was randomly assigned and counterbalanced with a 5-min rest separating conditions. EMG activity was recorded during the concentric and eccentric actions of each repetition. The data during each of the five repetitions were normalized to the data obtained during the 1-RM lift and the mean was used in the analysis. A 2×2×2 (Condition × Exercise × Action) ANOVA with repeated measures revealed a significant Condition main effect for the VM (F_1,23=11.25, p=.003), as EMG activity was greater during the braced condition (91.0±.04%) as compared to the unbraced condition (82.8±.03%). As expected, VM and VL activity were greater during the concentric action of each exercise as compared to the eccentric action. However, this was not affected by bracing or the type of exercise. These results suggest that patellar bracing might enhance VM activity during both open and closed kinetic chain knee extension, providing greater benefit during rehabilitation.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-102–S-103.

Effectiveness Of Prophylactic Hyperextension Elbow Braces On Limiting Active And Passive Elbow Extension Pre And Post-Physiological Loading

AW Lake ¹, MR Sitler ¹, DJ Stearne ¹, CB Swanik ¹

Abstract

The purpose of this study was to determine the effectiveness of three prophylactic hyperextension elbow braces on limiting active and passive elbow extension pre- and post-exercise. Twenty-one Division I intercollegiate football players (age 20.15 ± 1.27 years; height 184.40 ± 9.90 cm; mass 102.87 ± 22.02 kg) participated in the study. Independent variables were brace condition (Breg Functional Elbow Brace [Breg], PRO 470 Kendall Elbow Brace [Pro], and DonJoy Elbow Guard [DonJoy]), test mode (active and passive), and test session (pre- and post-exercise). The dependent variable was elbow extension angular displacement, which was measured with the PEAK Motus Motion Analysis System. The braces were set to a 30° extension limit (confirmed goniometrically) for all testing, randomly assigned, and fitted according to manufacture guidelines. Strap tension was standardized (10 lbs) with a Punctate Tenderness Gauge during brace application. For the passive trial, a MicroFET Hand Held Dynamometer was used to apply 10 ft/lbs of force to the ulnar styloid process in the sagittal plane in the direction of extension. Testing consisted of participants completing a 3 sub-maximal repetition warm-up of active elbow extension through the available range of motion, followed by a 1 minute rest period. Three trials for record were then completed for both testing modes. Active tests were conducted before passive tests. The exercise protocol was then completed which consisted of repeated elbow extension, totaling 1, 200 ft/lbs of work at an angular velocity of 360°/sec on a BIODEX Multi-Joint Testing and Exercise Dynamometer. Post-exercise testing was conducted in the same manner as the pre-exercise testing. Results revealed that none of the braces limited elbow extension to the 30° set limit. The average extension angles attained for the three braces for active pre-exercise, active post-exercise, passive pre-exercise, and passive post-exercise were as follows: Breg 16.9, 15.4, 13.9, and 12.1°; DonJoy 11.9, 11.8, 7.1, and 6.2°; and Pro 4.1, 3.5, 1.8, and 0.7°, respectively. A three-factor repeated measures analysis of variance revealed that regardless of test session, the descending hierarchial angular dispacement order was as follows: Pro significantly greater than DonJoy and Breg, and DonJoy significantly greater than Breg. In conclusion, none of the braces tested limited elbow extension to the 30° set limit. However, all of the braces were successful in preventing the elbow from reaching the vulnerable position of 0 to −10° hyperextension. The Breg Functional Elbow Brace was the most effective for this purpose.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-103.

Prophylactic Knee Bracing And Local Fatigue Have No Effect On Joint Position Sense Of The Uninjured Knee In A Closed Kinetic Chain

MT Culp ¹, KM Guskiewicz ¹, SE Ross ¹, WE Prentice ¹, SM Oliaro ¹, CN Brown ¹

Abstract

Inhibited proprioception of the knee joint may increase the risk of injury. Current knee brace studies have resulted in conflicting findings with no consensus on their benefits. The purpose of this study was to determine the effects of prophylactic knee bracing and fatigue on active joint position sense of the uninjured knee. Twenty healthy, physically active male volunteers (age = 20.95 ± 1.9 years, height = 180.34 ± 6.11 cm, mass = 79.75 ± 15.29 kg) volunteered for participation. Subjects performed double-leg squats to two predetermined knee flexion reference angles (45° and 75°), and maintained these selected positions for 10s. Joint position sense was assessed by having subjects actively reproduce these knee flexion angles during a single-leg squat with and without a prophylactic knee brace, during fatigued and non-fatigued states. Subjects were fatigued using a resisted squatting protocol. Fatigue was defined as the point in time when subjects failed to complete two successive squat cycles or fell four squat cycles behind the set pace. Joint position sense was measured as the absolute degree of error between the reference angle and the reproduced angle for each trial. Testing consisted of two test sessions (fatigue and non-fatigue) conducted three days apart. Statistical significance was established a priori at a = 0.05. Repeated measures ANOVA indicated that the brace (F_1,19 = 1.01, p = 0.33) and fatigue (F_1,19 = 0.04, p = 0.84) main effects were not significant, nor was the brace by fatigue interaction (F_1,19 = 0.11, p = 0.74) for the 45° condition. Mean absolute degrees of error at 45° were as follows: 7.36 ± 6.47° (non-braced, non-fatigued), 6.85 ± 5.70° (braced, non-fatigued), 7.69 ± 4.33° (non-braced, fatigued), and 6.91 ± 4.67° (braced, fatigued). Similarly, the brace (F_1,19 = 0.01, p = 0.96) and fatigue (F_1,19 = 2.24, p = 0.15) main effects and brace by fatigue interaction (F_1,19 = 0.08, p = 0.78) were not significant for the 75° condition. Mean absolute degrees of error at 75° were as follows: 6.25 ± 4.97° (non-braced, non-fatigued), 6.11 ± 3.76° (braced, non-fatigued), 4.97 ± 3.69° (non-braced, fatigued), and 5.19 ± 2.87° (braced, fatigued). The results of this study indicate that neither prophylactic knee bracing nor fatigue have significant effects on knee joint proprioception. Thus, prophylactic knee bracing appears to neither enhance nor inhibit proprioception at the knee. These results emphasize the function of prophylactic knee braces in absorbing external loads placed on the knee, suggesting little or no contributions to proprioceptive sense.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-103.

External Ankle Stabilization: Male High School Basketball Players' Perceptions Regarding Specific Use And Functional Performance

RE Bomar ¹, ML Cordova ¹, TJ Demchak ¹, JR Storsved ¹

Abstract

The purpose of this study was two-fold; first, it was to assess athletes' perceptions regarding the efficacy external ankle support on functional performance. Secondly, we sought to gain specific knowledge as to why athletes choose the type of ankle support that they wear. A 34-item questionnaire containing the following construct areas was devised: 1) demographic information, 2) medical history regarding ankle injuries, 3) knowledge and preference of ankle taping and bracing, 4) opinions toward the use of ankle bracing, and 5) opinions toward the use of ankle bracing. The survey was designed to assess high school male basketball players' perception of functional performance while wearing an external ankle support. Through pilot testing, the a priori internal consistency reliability estimate (Cronbach's alpha) was r = .78. The face validity and content validity was established through a comprehensive literature review and expert critique from certified athletic trainers (ATCs). The items from the survey were statistically analyzed used descriptive and qualitative methods. A total of 770 surveys and study materials were sent to 22 high schools in the Wabash Valley and Indianapolis, Indiana areas that employ ATCs. The ATCs then distributed these materials to their male basketball players for participation. A total of 115 male high school basketball players (grades 9–12, averaging 16.5 yrs of age) voluntarily responded to the survey after informed and parental consent was obtained (approximate return rate of 15%). The results of this study showed that 68% of the respondents participated in 7 or more years of organized basketball, where 76% of total respondents experienced at least one ankle injury during their playing time. The majority of athletes who sustained an ankle injury (54%) saw an ATC, and was advised to wear external ankle support. Of the basketball players surveyed 29% were undecided regarding the comfort and fit of ankle braces, as well as their effects (65%). Compared to ankle bracing, only 25% felt that ankle taping was more comfortable. Additionally, 45% of the respondents were undecided regarding the support offered by ankle taping. With respect to functional performance, 42% strongly agreed or agreed there was no limitation with ankle bracing; whereas, only 25% felt that ankle taping did not limit their performance. Despite the indecision toward ankle taping, male high school basketball players show no marked preference between ankle taping and bracing. Moreover, the use of ankle bracing and taping is not generally perceived to limit functional performance.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-104.

Concepts Of Quality For Post-Certification Graduate Education

JG Seegmiller ¹

Abstract

The purpose of this study was to: (a) identify predominant contributors to quality for post-certification graduate education (PCGE) in athletic training, (b) determine if athletic training educators view accreditation to be important for PCGE, and (c) determine if there is a significant difference in perceived contributors to quality between different categories of athletic training educators. A convenience sample of certified athletic trainers (N=353) who attended the 2003 NATA Educator's Conference in Montgomery, TX was used for this study. One hundred ninety-six questionnaires were returned for a response rate of 55.52%. Eighty-eight (45.36%) of the participants had earned doctoral degrees, 54.56% had earned masters degrees. The sample included educators from 12 of the 14 NATA-accredited PCGE programs. This descriptive research study focused on content analysis of the PCGE accreditation standards leading to a survey in which the relative significance of the identified criteria in contributing to the quality of a PCGE program were ranked by athletic training educators. A reliability analysis of the survey resulted in a coefficient of .8314. The survey instrument consisted of a demographic section, a close-ended 23-item 4-point questionnaire section, and an open-ended question section. For statistical analysis, the four descriptors of greatly, moderately, minimally, and none were assigned numeric values of 4, 3, 2, and 1 respectively. Descriptive statistics, ANOVA, t-tests, a Pearson correlation, and a factor analysis were calculated for quantitative questionnaire items using SPSS software. Responses indicated that the greatest contributors to program quality were: (1) adequate number of qualified faculty (mean 3.86 ± .389), (2) program director's strong academic orientation and interest in student professional preparation (mean 3.75 ± .456), (3) goals and objectives related to enhancing students' critical thinking skills (mean 3.72±.507), and (4) adequate numbers of qualified athletic training staff and other allied health personnel (mean 3.70 ± .511). Responses to the question- To what extent does accreditation for post-certification graduate education programs contribute to quality-indicated moderate support for accreditation at the PCGE level (mean 3.08 ± .811). The majority of respondents (46.99%) selected moderately, 32.79% chose greatly, 15.86% selected minimally, and 4.37% of respondents indicated that accreditation contributes nothing to quality. Results indicted a significant difference (p ≤ .001) among athletic training educators over the contribution of research and clinical education to quality in post-certification graduate education. Respondents with doctoral degrees (n=85, mean 3.38 ± .636) indicated that research contributed significantly more than educators with master's degrees (n=106, mean 2.97±.786). Whereas, respondents with master's degrees (mean 3.76 ± .491) indicated that clinical education was a greater contributor to quality than educators with doctoral degrees (3.44 ± .663). Item analysis of the open-ended qualitative section indicated that the major contributors to program quality were: (1) curriculum, (2) research, (3) faculty/administration, and (4) clinical experience. The results of this study indicate that accreditation of athletic training programs at the graduate level is not considered a primary defining indicator of quality by the majority of athletic training educators. Furthermore, unless accreditation provides a benefit to both students and institutions, it is unlikely to be perceived as necessary for program excellence. The division among athletic training educators over the place of research and clinical education in PCGE indicates a lack of consensus regarding their relative importance for graduate study.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-104.

A Qualitative Study Examining Role Strain Among Athletic Training Educators Using Computer-Aided Communication

RS Charles-Liscombe ¹, KM Jamieson ¹

Abstract

Previous research in athletic training indicates that certified athletic trainers (ATCs) have multiple job responsibilities, have difficulty achieving tenure and promotion, experience a moderate degree of burnout, and a moderate rate of attrition. Recent reform and growth within athletic training education has added complexity to the role of faculty and clinical instructors (CIs). Previous research in nursing and other allied health professions indicates that faculty experience role strain or the “the subjective state of emotional arousal in response to external conditions of social stress” (Hardy & Hardy, 1988, p. 165). No research in athletic training has examined role strain among educators or clinicians. Furthermore, no research in athletic training has utilized computerized focus group discussions for qualitative research. Therefore, the purpose of this qualitative investigation was to examine and to describe the perceptions of faculty and CIs as they encounter, cope, and manage role strain in CAAHEP accredited programs using online, asynchronous communication as a medium for qualitative, focus group research. A group of 10 ATCs, 5 males and 5 females, with at least one year of experience in clinical practice and clinical instruction and employed at CAAHEP accredited programs, volunteered to participate in this study. All three NCAA divisions and all degree granting Carnegie classifications were represented. Subjects were assigned pseudonyms to protect anonymity and confidentiality. Subjects participated in a 6-week series of semi-structured, asynchronous discussions via a Blackboard Learning Systems (Blackboard Inc., Washington, D.C.) on-line community. A constant comparative analysis method was used during data collection to generate follow-up questions. Transcripts were read, indexed, and analyzed between each discussion board posting and at the conclusion of the study. Results indicate that these faculty members and CIs experience varying degrees of role strain in their daily work. They have multiple role set members, experience role overload, and role conflict between academic, clinical, administrative, and personal life demands. Role ambiguity, role overqualification, and role incompetence were not identified as key contributors to role strain in this focus group. Faculty and CIs with less than 10 years of experience expressed greater frustration and difficulty with role strain than their more senior colleagues. These findings indicate two possibilities for action a) faculty and CIs must develop the coping skills needed to negotiate role demands at CAAHEP accredited institutions; and b) administrators, faculty, and external reviewers must work in collaboration to minimize the role strain experienced by athletic training faculty and CIs.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-105.

Engagement Theory In Action: An Investigation Of Athletic Training Program Directors

KS Peer ¹

Abstract

Rooted in engagement theory, instructional good practice assesses the degree to which typical student instructional experiences are consistent with established principles of good practice in undergraduate teaching (Angelo & Cross, 1993; Chickering & Gamson 1987). This survey investigated the degree to which the practices of athletic training education program directors reflect instructional quality indicators as demonstrated on self-reflective Faculty Inventory. The inventory was collectively scored and by seven subscales. Demographics for Carnegie Classification, Appointment Type and Degree Type were collected. The Seven Principles for Good Practice in Undergraduate Education—Faculty Inventory (Johnson Foundation, 1989) consists of 70 components in seven subscales scored on a 5-point Likert scale. Non-probability sampling of Program Directors from CAAHEP-accredited, entry-level Athletic Training Education Programs (N = 125) yielded seventy-three subjects (58.4%). Thirty-six (49.3%) research/doctoral and 37 (50.7%) comprehensive/baccalaureate institutions responded. Sixty-four (87.7%) had administrative/academic appointments and 9 (12.3%) academic/athletic appointments. Fifty-six (76.7%) had degrees in Education with 17 (23.3%) holding other degrees. Descriptive statistics including means and standard deviations, Pearson Correlations, and Multiple Linear Regression using an F test were performed. Mean scores for Research/Doctoral (R/D) institutions were higher on the total score (267.06/33.58) than the Comprehensive/Baccalaureate (C/B) participants (264.62/25.32) and on all but two of the subscales - Cooperation Among Students and Active Learning. Participants from the Academic/Administrative appointments had mean scores (267.41/30.00) higher than Academic/Athletic appointments (254.56/24.56) on the total inventory score and in all but one of the subscales – Respects Diverse Talents and Ways of Learning. Participants with Education degrees had mean scores (266.51/29.37) higher than those without Education degrees (263.41/30.72) for the total inventory and in all but two of the subscales - Faculty-Student Contact subscale and the Cooperation Among Students. Multiple linear regression yielded non-significance for each of the independent variables. The full model used was y (scores) = a0u + appt. + class + degree + error with restricted models dropping one of the variables to detect which variable accounted for a unique amount of variance. Degree Type did account for a unique amount of variance over and above Carnegie Classification and Appointment Type on the Faculty Inventory. The t values were not significant for any of the measures. However, appointment type and active learning (ALNG) had a significance level of .061 and appointment type and high expectations (HEX) had a significance level of .071. The results provide insight regarding what practices are being utilized in the classrooms and clinical settings. The overall mean scores reflected that, at the very least, the subjects are using good practices on an occasional to frequent basis in the delivery of their programs. These behaviors support a multidimensional, comprehensive approach to quality assessment.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-105.

Psychomotor Performance And Learning Style Effects Of A Computer-Based Interactive Multimedia Program

R Wagner ¹, DR Gorman ¹, J Bonacci ¹, WF Brescia ¹, BS Brown ¹, SL Hunt ¹

Abstract

The impetus of this study was the lack of research on psychomotor performance and learning style effects of computer-based instruction (CBI). To date, few athletic training researchers have examined these variables. Although educational specialists believe that CBI is an economical and effective tool for enhancing educational effects, the implications for teaching psychomotor skills is still unclear. The purposes of this study were to (a) to explore whether the use of a computer-based interactive multimedia program to teach students the Lachman's test would result in a higher level of psychomotor performance than students taught using traditional laboratory instruction (TLI), and (b) to investigate whether the effectiveness differed by learning style. Sixty undergraduate students with no prior knowledge of the Lachman's test were the participants for this study. The participants were assigned to either the CBI group (n=30) or the TLI group (n=30) based on their learning style, as defined by the Marshall and Merritt Learning Style Questionnaire. Due to the exploratory nature of this study, an alpha level of .10 was used for all statistical analyses. A 6-item psychomotor performance checklist tool was used to rate the participants' psychomotor performance on six critical steps. The steps were based on a description provided by Evaluation of Orthopedic and Athletic Injuries, 2^nd edition (Starkey & Ryan, 2002). A paired samples t-test revealed a significant difference between the two groups on mean levels of psychomotor performance, t(29)=–3.008, p=.005. The TLI group (M=75.67) performed significantly better than the CBI group (M=49.33). To determine whether students with active-experimenter learning and reflective-observer learning style differed on psychomotor performance based on mode of instruction, a repeated measures one between/one within factor ANOVA was conducted. The multivariate test for differences was not statistically significant (Wilks lambda = .996; F (1, 28) = .114; p = .738) indicating that there was not a significant effect of learning style on psychomotor performance. The findings of this study suggest that TLI was more effective than CBI in teaching the Lachman's test. In addition, learning style does not have an effect on psychomotor performance. Future research should continue to focus on the learning style effects of computer-based instruction. To date, this study is the second to examine the learning style effects of an interactive multimedia program in the athletic training field. Furthermore, researchers should abandon the paradigm of simply comparing instructional methods and focus on identifying those variables that influence effective computer based instruction delivery.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-105–S-106.

Characteristics Of Athletic Training Faculty Jobs For 1999-2003

D Fuller ¹, S Walker ¹

Abstract

Throughout the year there are numerous athletic training (AT) jobs advertised, with more and more requiring classroom or clinical teaching responsibilities. The purpose of this study was to assess various job characteristics of athletic training faculty positions over the past 4 years. Job descriptions were collected from internet websites of the National Athletic Trainers' Association (NATA), Chronicle of Higher Education, and National Collegiate Athletic Association (NCAA). Any AT job description that included academic teaching was considered an Athletic Training faculty position. Various job characteristics from these faculty postings were analyzed with SPSS-X 11.0. Of the 563 jobs advertised, there were 186 Program Director (32%), 40 Clinical Coordinator (7%), 214 Assistant Professor (38%), and 124 Instructor (22%) positions. A number of these jobs also required duel appointments or partial appointments in intercollegiate athletics, especially those with Instructor status. Overall, 35% indicated that they were tenure track appointments, 7% were non-tenure track, and 58% did not report this qualification. Forty-one percent of the Program Director and 53% of the Assistant Professor positions were listed as tenure track appointments. Since many of these jobs were at the Assistant Professor rank or higher, doctoral degrees were required (39%), preferred (28%) or unknown (33%). Forty-two percent of jobs for Program Directors required a doctoral degree, while 46% preferred it. Assistant Professors were similar with 52% required and 37% preferred. Most of these jobs were from District 4 (24%), District 3 (18%), and Districts 5 and 9 (both with 13%). Furthermore, the states that were most representative were North Carolina (n=41, 7%), Ohio (n=31, 5%), and Virginia (n=29, 5%). Whether an athletic trainer is finishing their doctoral studies, pursuing a college/university athletic training staff position, or even transferring to another location, it appears that there are an abundance of jobs available at this time. This information should be useful for both job seekers as well as those trying to obtain a new faculty (or staff) position at their institution. It was also interesting to see how much information, such as qualifications and responsibilities, were missing from many of these job advertisements. Perhaps these job characteristics may encourage some athletic trainers to pursue their doctoral degrees, or even better prepare themselves while they are in undergraduate and graduate studies.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-106.

An Investigation Of College Students' Recognition And Recall Monitoring Ability

K Kusumoto ¹, CL Stemmans ¹, DJ Langley ¹, K Boone-Tovey ¹

Abstract

Metacognitive ability refers to a learner's ability to monitor, evaluate, and develop plans for his or her educational goals. Knowledge Monitoring Accuracy (KMA) measures the accuracy of the monitoring portion of metacognitive abilities. Through a ratio, it identifies differences between the students' knowledge estimate and their actual task performances. The purpose of this study was to examine the effect of recognition and recall test items and academic level on knowledge monitoring accuracy. Additionally, we assessed whether KMA correlated to actual academic achievement. We used a 2 × 3 factorial design in this study. The first independent variable was test item type with 2 levels (recognition and recall), and the second variable was academic levels with 3 levels (freshman/sophomore, juniors, and seniors). The dependent variable was the knowledge monitoring accuracy. Thirty-three undergraduate students (f=20, m=13; age=21.2 ±3.0 yrs) volunteered to participate in this study. Each subject completed 4 KMA and specific knowledge content quizzes administered in an Athletic Training Medical Terminology class. This study indicated that the subjects demonstrated significantly higher recognition monitoring accuracy than recall monitoring accuracy (t₁₃₁ = 60.6, P < .01). There were no significant differences in knowledge monitoring accuracy between the academic levels of the students on recognition items (F_{2, 129} = .14, P > .05) or recall items (F_{2, 129}= 1.39, P > .05). A positive correlation was found between the recognition monitoring accuracy and the quiz score (r = .62, P < .01). This study indicated that students demonstrated better recognition monitoring ability than recall monitoring ability. This study also indicated that academic achievements were not related to academic levels of college-aged students. Academic success is positively correlated with accurate monitoring ability. Monitoring knowledge is the initial process of metacognition. Metacognition significantly influences students' academic achievements. Correctly ‘knowing what you know’ is essential for the self-realization of learning. Knowledge of academic accuracy is necessary for students to become successful independent learners.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-107.

Does Varying Pre-Jump Squat Exercises Influence Vertical Jump?

M Takahashi ¹, BC Mangus ¹, W Holcomb ¹, JA Mercer ¹, W McWhorter ¹

Abstract

For many years athletes have used the half-squat as a warm-up for many different exercises or activities. Some argue the half-squat can be a precursor to various injury pathologies in the athlete due to the depth of the squat. The purpose of this study was to compare the effect of the half-squat or quarter-squat exercise on vertical jump (VJ) heights. Ten male subjects (age = 23.4 ± 2.0 yr; height = 177.0 ± 5.0 cm; mass = 83.1 ± 9.7 kg; the maximum half squat mass = 138.0 ± 23 kg; the maximum quarter squat mass = 172.0 ± 24 kg) experienced with the squat exercise were required to attend 3 separate testing sessions. All testing sessions were scheduled 3–5 days apart to ensure muscles were rested and subjects were also informed not to participate in weight training exercises during the experimental window. The first session was used to determine their 1 RM for each squat exercise and complete the control portion. Each subject performed the VJ after a 5 minute treadmill warm-up followed by sitting quietly for 30 minutes then doing the same procedure to determine their VJ height under control conditions. The next two sessions were designed to examine the effect of the half and quarter-squat exercise on the VJ. Subjects performed 4 warm-up squat sets followed by 1 repetition with the weight of 90% of 1 RM half squat or quarter squat. Each subject's VJ height was calculated by integrating the vertical ground reaction force (Kistler Inc. 4 second sampling at 1000 Hz). Vertical jump height was the dependent variable and squat exercises (half and quarter) was the independent variable. A one way ANOVA analysis of the data indicated no difference in jump heights after any of the conditions including a control group (F = 3.096, p = 0.070). Pearson correlations between the relative strength ratio and the difference in averaged jump heights before and after the half and quarter-squat conditions did not indicate a strong correlation (r = − 0.128, p-value = 0.724; and r = − 0.189, p-value = 0.601, respectively). Visual inspection of the raw data reveal that five of the subjects increased jump height after both the half and the quarter squat exercises, therefore, the influence of squat exercise on VJ performance may be subject dependent. It might be that some individuals derive different benefits from each of the squat exercises.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-107.

The Effects Of A Time-Limited Plyometrics Program On Neuromuscular Responses And Vertical Ground Reaction Forces In Collegiate Soccer Players

B McDowell ¹, BL Van Lunen ¹, ML Walker ¹, W Romani ¹, JA Oñate ¹

Abstract

Several investigations have noted altered kinetic and neuromuscular landing patterns in adolescent female athletes following various plyometrics programs. The purpose of this study was to investigate the effects of a time-limited plyometrics training program on neuromuscular responses and peak vertical ground reaction force in a group of uninjured Division I collegiate soccer players. Sixteen (8 male, age=19.38 ± 1.4 yrs, ht=178.44 ± 8.99 cm, mass =80.38 ± 8.37 kg; 8 female, age=19.75 ± 0.71 yrs, ht=163.83 ± 4.30 cm, mass =62.13 ± 6.29 kg) athletes completed the testing protocol and plyometric training. All subjects had their right limb tested prior to and after the training program. Data were collected using surface electromyography (sEMG) and an AMTI force plate. Surface electrodes were applied to the vastus medialis oblique (VMO), vastus lateralis (VL), semimembranosus (SM), and biceps femoris (BF) and they performed three drop jumps from a height of 50 centimeters, landing with both feet on one force plate. During the following 11 weeks, subjects completed a time-limited plyometric training program (1x week) designed and supervised by the university strength and conditioning specialist. The dependant variables included time from initial contact to onset (onset time), time to peak (peak time), and duration time of muscle activity (duration) of the quadriceps and hamstrings muscles, as well as peak vertical ground reaction force (PVGRF). Comparisons were made between pre- and post-testing sessions, as well as between gender. Separate 2×2×2 and 4×2×2 repeated measures ANOVA's were used for EMG data analyses. Force plate data were analyzed using a 2×2×2 ANCOVA, with individual bodyweight as the covariate. Statistical significance was set at p<0.05. Main effects were found for session in onset times for the VMO and VL, as well as peak times of the VMO and VL. All times significantly increased from pre-test to post-test indicating a delay in quadriceps muscle activation as compared to baseline testing for both groups. An interaction was noted for gender and muscle onset time. Males tended to activate the VMO and BF earlier than females and the SM later. No significant differences were found for PVGRF. An off-season collegiate training program consisting of plyometrics once a week may be effective in changing muscle activation patterns in collegiate soccer players, yet was not effective in decreasing PVGRF. Future research is needed to evaluate the efficacy of increased frequency of plyometrics training and its effects on a similar population.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-107–S-108.

Lower Extremity Excitation During Maximum Voluntary Teeth Clenching Does Not Influence Vertical Jump Height

JA Bland ¹, JM Hart ¹, SM Zinder ¹, BM Gansneder ¹, CD Ingersoll ¹

Abstract

Force of lower extremity muscle contraction may be facilitated through maximal voluntary teeth clenching. Teeth clenching is common in athletes performing strenuous maneuvers. However, research in this area has focused on non-dynamic maneuvers and have not addressed muscle power. A standard boil-and-bite mouthguard can improve the ability to produce force during a clench due to increased tooth contacts. The greater the force of teeth clenching the greater the neural excitability throughout the muscles. The purpose of this study was to determine if lower extremity muscle strength and power measured by vertical jump height could be improved in conjunction with a maximal voluntary teeth clenching. 110 male and female division I, varsity athletes each performed three maximal vertical jumps for three different treatment conditions. The treatment conditions included teeth clenching with boil-and-bite mouthguard (MG), teeth clenching without mouthguard (CL) and no clenching (NC) for a total of nine jumps per subject. Order of jumps was counterbalanced to control for fatigue and learning. Subjects were given about 10 seconds to recover between each jump. Vertical jump height was assessed by measuring the airborne time from the instant the foot left the ground to the instant it touched down using a foot switch sensor. Time off the ground was converted to maximal vertical displacement in meters. Data were collected using Biopac system, MP100 and analyzed with Acqknowledge software. A repeated-measures ANOVA revealed that there were no significant differences in mean vertical displacement between the three treatment conditions, MG= 0.452±0.09m, CL=.451±0.09m, NC=0.446±0.09m, F(2, 18) = 2.06, P = .13, eta² =. 019, 1- beta = .421. Vertical jump height is not facilitated in conjunction with a maximal voluntary teeth clench.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-108.

Bilateral Asymmetries In Flexibility, Stability, Power, Strength, And Muscle Endurance Associated With Preferred And Nonpreferred Legs

D Valdez ¹, MB Horodyski ¹, ME Powers ¹, M Tillman ¹, R Siders ¹

Abstract

When assessing acute injury or progression during rehabilitation, the uninjured limb is commonly used as a pre-injury model. This model assumes the limbs are symmetrical, which may not be true in all athletes. It is possible that one-legged athletes (1LA) (e.g., jumpers/kickers) may develop bilateral asymmetries as a result of specific training. Thus, the purpose of this study was to determine whether training induced asymmetries in flexibility, stability, power, strength, and muscular endurance existed between the preferred and nonpreferred legs of 1LA. Five characteristics were measured in three groups of subjects: nonathletes (NAS) (n=8, age=21.0 ±1.2 yr, height=170.1 ±6.9 cm, mass=68.5 ±13.1 kg); two-legged athletes (2LA) (n=8, age=20.8 ±1.3 yr, height=169.9 ±8.6 cm, mass=66.3 ±10.0 kg), and 1LA (n=8, age=20.3 ±1.4 yr, height=179.7 ±11.0, mass=72.9 ±13.9 kg). Quadriceps and hamstring flexibility were measured using an inclinometer during a passive prone knee-flexion test and a supine passive straight-leg raise, respectively. Stability was assessed by having subjects jump onto a forceplate and stabilize on one leg. One-legged hop distance (OLH) represented power. Quadricep and hamstring strength at 60°/sec and muscle endurance at 180°/sec were measured isokinetically. Leg preference was determined using three tasks: kicking a soccer ball, stepping on an object, and smoothing out sand. Two by three factorial analyses of variance (ANOVA) with repeated measures were used to determine if differences existed in the legs (preferred, nonpreferred) by group (NAS, 1LA, 2LA) for flexibility, stability, OLH, strength, and muscle endurance. Tukey's HSD post hoc test was performed to assess differences as necessary. The ANOVA revealed no significant interactions between leg preference and group for flexibility, stability, OLH, strength, or muscle endurance. However, a group main effect was revealed when strength and OLH scores from both legs were combined. Tukey's post hoc test revealed that 1LAs were significantly stronger isokinetically (quadriceps, P=0.0006; hamstring, P=0.024) and jumped significantly farther (P<0.001) compared to the NASs and 2LAs. Observed differences among groups could be a result of training level differences (i.e., varsity vs. recreational) affecting exercise volumes and intensities. The lack of significant asymmetries between preferred and nonpreferred legs suggests that an inadequacy in training elicited asymmetrical adaptations. In conclusion, asymmetries in the preferred and nonpreferred legs did not exist in the subjects in this study; hence, leg preference could not be associated with asymmetries in flexibility, stability, power, strength, or muscle endurance.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-108.

Two-Footed Vertical Jump And Single-Leg Hop Before And After Training With A Pilates-Based Conditioning Program In College-Level Modern Dancers

LF Mortensen ¹, DA Kaiser ¹, SL Gibb ¹, PE Allsen ¹

Abstract

The purpose of this study was to determine the effect of a Pilates-based conditioning program on two-footed vertical jump and single-leg hop of modern dancers. Twenty-eight healthy subjects (all females, age = 20.0±6.0 years) were recruited from two entry-level modern dance classes taught at Brigham Young University. All of the subjects had prior dance experience, although none were elite dancers. The subjects were self-assigned to one of two groups. The control group (n=15) participated in their technique class only. The class met Monday through Friday for 70 minutes of dance activity. The experimental group (n=13) participated in the daily technique class, as well as a 50-minute Pilates-based conditioning program three days a week. A pre-test was given to all subjects with each one performing a maximal two-footed vertical jump, and maximal right foot and left foot hops. The starting position for the jumps (both feet in first position for two-footed jump, jumping foot turned out and non-jumping foot in a sur le cou de pied position for the single leg hops) were very familiar to the dancers. These jumps were performed on the Just Jump or Just Run device (Probotics, Huntsville, AL). This device provides a valid measure of jump height by measuring the length of time from when the subject jumps off the test mat until they land back on the mat. The highest of three jumps was used for analysis. At the conclusion of the eight-week study period, a post-test was administered in the same manner as the pre-test. To determine the significance of the pre-test and post-test results, a paired-samples t-test was computed. The results revealed a significant improvement for the experimental group's right foot hop t(12)=2.23; p<0.0457, and the experimental left foot hop t(12)= 2.57; p<0.0244. There was no significant improvement in the experimental groups two-footed vertical jump t(12)=1.51; p< 0.1576. There was no significant improvement in any of the control group's jumps; right foot t(14)=1.28;p< 0.2198; left foot t(14)=–0.92; p<0.374; two-footed t(14)=1.32; p<0.2078. These results show there may be an advantage to using the Pilates-based conditioning program to improve single-leg hop height in modern dancers.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-108–S-109.

Mild Exercise During A Simulated Half-Time Does Not Improve Vertical Jump Performance

HL Cady ¹, CL Docherty ¹, BM Gansneder ¹, SM Zinder ¹, CD Ingersoll ¹

Abstract

Athletes often stretch and warm-up prior to athletic competition to decrease injury and increase performance. The majority of athletic competitions have a half-time where athletes rest to help restore energy for the remainder of the game. No studies to date have examined the effects of activity during half-time to further benefit athletes' performances for the remainder of the game. Therefore, the purpose of this study was to determine the effect of mild half-time exercise on future vertical jump performance. A 1 × 4 factorial was used in this study. The independent variable was exercise group at 4 levels and the dependent variable was maximal vertical jump. The study took place on a hardwood basketball court at Cocke Hall, Virginia Military Institute, Lexington, Virginia. Eighty-eight men and women (21.6 ± 3.38 yrs, 70.1 ±3.92 cm, 179.1 ± 36.26 kg) participated in this study. All subjects were healthy individuals, 18 years of age or older, with no current or previous injuries within the previous 3 months. The subjects were randomly assigned into one of four half-time groups. All subjects performed 3 vertical jump pre-tests using the Vertec® (Cranston, RI), followed by twenty minutes of exercise which simulated a first half of an athletic game. The participants then performed mild exercise, at a constant, predetermined speed and resistance for varied intervals depending on group membership for the half-time period. Group 1 performed no activity for 8 minutes, group 2 performed no activity for the first 4 minutes then rode a stationary bike for 4 minutes, group 3 rode a bike for the first 4 minutes then performed no activity for 4 minutes, and group 4 rode a bike for 8 minutes. Three vertical jump post-tests immediately followed the simulated half-time period. Maximal vertical jump was used for both the pre and post-test vertical jumps. Vertical jump percent change was calculated and used in a one-way analysis of variance (ANOVA). No significant difference in vertical jump performance was found between the groups (F_3,84 = 1.288, p = .284, Eta² = .044, 1-ß = .333). These data suggest that the amount of exercise during a simulated 8 minute half-time does not affect future VJ performance.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-109.

Force-Length-Velocity Comparison Of Hamstring And Quadriceps In Isometric And Isokinetic Contractions With Young Subjects

M Tsuruike ¹, MA Hoffman ¹

Abstract

It is generally accepted that as the angular velocity of a joint increases, the force produced about that joint decreases. This is commonly referred to as the force-velocity relationship. A similar relationship exists between sarcomere length and force production during isometric contractions and is known as the force-length relationship for isometric contractions. Both of these relationships have been shown to describe activity of the quadriceps muscle group. However, we have not been able to establish these relationships in the hamstring muscle group. Therefore, the purpose of this investigation was to systematically determine if the hamstring muscle group demonstrated either the force-velocity or force-length relationships existed in a group of young subjects. Twelve healthy young subjects (21.2±1.2 yrs) participated in this study. All subjects were tested in the sitting position, and the peak torque (Nm) was generated during both isometric and isokinetic contraction using a KIN-COM dynamometer. During the isometric contractions the knee joint was randomly set at 10 degree intervals between 10 and 90 degrees of knee flexion. The subjects then performed 3 trials of their maximum voluntary contraction (MVC) for 4 seconds with the intervals of 6 seconds between each of the trials. In the isokinetic contraction, the angular velocity was randomly set at 30, 90, 150 and 210deg/sec, and the subjects performed 3 trials of their MVC for each of the angular velocity both concentrically and eccentrically. All torque values were divided by body mass (Nm/kg). With regard to the isometric contraction, there was a significant relationship in the force-length curve for the knee flexion between 10 and 90deg (r²=.12, p<.05); yet, no significant relationship was found between 10 and 60deg. There was a significant difference in the mean value of peak torque between 30 and 150 or 210deg/sec (1.61 and 1.22 or 1.26Nm/kg, p<.05); yet, no significant relationship in the force-velocity curve was found between 90 and 210 deg/sec. This investigation clarified that the leg curl produced by the hamstring showed neither the force-length relationship until 60deg of flexion, nor the force-velocity relationship between 90 and 210deg/sec. It is unclear as to why this relationship does not appear to exit in the hamstring muscle but it is hypothesized that it may be related to the characteristics such as ratio of muscle type fibers or functional demands.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-110.

Females Utilize Quadriceps Dominant Landing Strategies That Increase Knee Shear Forces And Internal Extension Moments

TC Sander ¹, BM Gansneder ¹, LK Bunker ¹, GA Gaesser ¹, EN Saliba ¹, DH Perrin ¹, SJ Shultz ¹

Abstract

Females appear to perform running, cutting and landing maneuvers in a manner that tends to increase anterior cruciate (ACL) loading and with quadriceps activation dominance. However, these variables have not been considered together and potential sex related differences in the onset latency and amplitude of muscular preactivity prior to completing these maneuvers have yet to be adequately explored. This investigation examined how kinetic and pre- and post-landing electromyographic variables were affected in males and females when performing a single leg landing task. Fifteen males (25.0 ± 4.1 yrs, 180.9 ± 6.6 cm, 84.2 ± 15.5 kg) and 15 females (24.0 ± 3.7 yrs, 166.1 ± 8.4 cm, 57.8 ± 8.9 kg) participated. Tibial anterior shear force (ASF) and hip, knee and ankle internal extension moments (IEM) were determined by inverse dynamics using the Vicon Motion Analysis System (Oxford Metrics, Oxford, England) upon single leg landing from a 40cm platform positioned 30cm from the edge of the force plate. Muscular preactivity onset (ON), preactivity mean amplitude (PRE) and post-landing mean amplitude (POST) were determined using the MA-300-16 EMG System (Motion Lab Systems, Inc., Baton Rouge, LA). Separate repeated measures analysis of variance were used to determine sex related differences upon landing in ASF at the knee, IEM at each lower extremity segment (hip, knee, ankle), and ONS, PRE and POST for the quadriceps (rectus femoris, vastus lateralis), hamstring (medial hamstrings, biceps femoris) and lateral gastrocnemius muscles. Analysis of kinematic data revealed that females experience 30% greater ASF (.21 ± .04 vs. .14 ± .04 N/kg; P < .001) and 37% greater lower extremity IEM (30.1 ± 7.5 vs. 21.7 ±5.2 Nm/kg*m; P = .002) when compared to males. Analysis of electromyographic data revealed that prior to landing, females preactivated their quadriceps 42% greater than males (41.1 ± 13.6 vs. 29.3 ± 9.8% MVIC; P =.009), and their gastrocnemius 49% less than males (68.1 ± 24.3 vs. 45.3 ±17.1% MVIC; P = .01). These findings further support that females utilize landing strategies that place greater emphasis on the knee extensor mechanism, resulting in joint forces that may increase strain on the ACL. More research is needed to explain the biomechanical implications and underlying causes of sex related differences in lower extremity motor control strategies, and the potential for altering these strategies through specific training interventions. Supported by NIH Grant MO1 RR00847

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-110.

Gender Differences In Knee Torques And Angles During Different Cutting Tasks

CA Trowbridge ¹, RP Winder ¹, I Hunter ¹, MD Ricard ¹

Abstract

Females experience a 3–5 times increased risk of non-contact ACL injury. Previous research suggests that females may decelerate and change direction differently than males and that these differences may contribute to their increased ACL injury rate. The purpose of this study was to evaluate knee torques and knee angles in the sagittal and frontal planes at initial contact and during the first 25% of stance for two 45° cutting tasks in recreationally active collegiate males and females. Seven females (age = 20.3 ± 1.4 yrs., height = 164.2 ± 6.0 cm, mass = 60.6 ± 7.6 kg) and six males (age = 23.3 ± 0.8 yrs., height = 178.6 ± 5.0 cm, mass = 76.5 ± 12.0 kg) with no history of serious knee injury performed six trials. Three trials at constant speed and three with deceleration were performed at 2.0–2.2 m/s (4.3–4.7 mph). Kinetic and kinematic data were collected using a five-camera motion analysis system (Motion Analysis Corp., Santa Rosa, CA), integrated with a force plate (AMTI, Newton, MA). Monitoring the change in speed in the horizontal and vertical directions on the force plate allowed for control of the two conditions. Data from the video system and the force plate were imported in to a desktop computer with a custom-made software package where joint angles and joint moments were calculated using the inverse dynamics method. Knee torque and angle in the sagittal and frontal planes were collected at initial contact. During the first 25% of stance, peak torque in the sagittal and frontal planes was determined along with the knee angle and time of stance at peak torque. A factorial ANOVA was used to compare gender across conditions (alpha=0.05). For the constant speed cutting and cutting with deceleration, females demonstrated significantly greater valgus angle at the knee (p = 0.0019 and p = 0.0046), less peak valgus torque (p = 0.0016 and p = 0.0094), and faster time to peak torque (p = 0.0054 and p < 0.0001). At initial contact females demonstrated greater knee flexion (p = 0.002 and p = 0.0068). Even though males had greater valgus torque, females reached their peak valgus torque earlier and exhibited a greater valgus position at this time. The frontal plane results are consistent with the position often noted at ground contact in female ACL injuries; however, the sagittal plane results are contrary. Therefore, future research should continue to explore gender differences so the relationship between position, torque, and ACL injury can be better understood.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-110–S-111.

Reliability And Validity Of The Landing Error Scoring System: Implications On ACL Injury Risk Assessment

DA Padua ¹, SW Marshall ¹, JA Onate ¹, AI Beutler ¹, KM Guskiewicz ¹, CA Thigpen ¹, SB Knowles ¹, WE Garrett ¹

Abstract

Typically, 3-D motion analysis is used to examine kinematic and kinetic variables associated with ACL injury risk. However, 3-D motion analysis systems are impractical in the clinical setting. Thus, reliable and valid measures of clinical motion analysis are needed to help identify individuals at potential risk for ACL injury. Therefore, the purpose of this study was to establish the reliability and validity of a clinical motion analysis tool. Healthy males (n=63) and females (n=54) participated in this study. Participants performed a jump-landing task by jumping from a 30-cm high box. Following the initial landing the participants immediately jumped upward for maximal vertical height. A force-plate and 3-D electromagnetic tracking system collected kinematics and kinetics data and two video cameras were used to record sagittal and frontal plane imagery during the jump-landing tasks. Video imagery was reviewed by a single rater using the Landing Error Scoring System (LESS). The LESS is a novel clinical motion analysis tool designed to identify errors in jump-landing technique. The intra-session and intra-rater reliability of the LESS were examined through ICC. Concurrent validity of the LESS was examined in two ways. First, LESS scores were compared between sexes using MANOVA. Second, the sample was dichotomized into groups: high error (H) and low error (L). The groups were formed by determining the upper and lower 25^th percentile LESS scores. Subjects whose LESS scores were in the lower 25^th percentile were assigned to group L (n=28). Subjects whose LESS scores were in the upper 25^th percentile were assigned to group H (n=30). MANOVA was used to compare groups on kinematic and kinetic variables measured during the jump-landing task. Our findings reveal that the LESS has excellent intra-session reliability (ICC_2,1=.90, SEM=1.05) and intra-rater reliability (ICC_2,k=.90, SEM=1.08). The LESS was able to differentiate between sexes as LESS scores were significantly higher in females (P=.003). Several kinematic and kinetic variables differed between the L and H groups. Group H demonstrated less (P<.05) hip flexion at initial contact, maximal knee flexion, knee and hip flexion displacement, time to peak vertical ground reaction force, and time to maximal knee and hip flexion. In addition, group H demonstrated greater (P<.05) peak vertical ground reaction force, anterior tibial shear force, knee valgus torque, and anterior shear ground reaction force. The LESS appears to be a reliable and valid clinical motion analysis tool. Additional research is needed to establish the predictive validity of the LESS. (Funded by the American Orthopaedic Society for Sports Medicine)

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-111.

Comparison Of Impact Force From 3 Heights During Ground Landing To Horizontal Landing

RG DeMont ¹, P Demey ¹, SP Ma ¹

Abstract

Mid- and long-term rehabilitation goals comprise of sport specific training techniques that often involve jumping techniques. Recent research has linked landing instruction to reduction in ligament injury. Height is a modified factor in jump training and there are devices that purport the ability to reduce impact of landing through graded resistance. The importance of landing height and method were examined in this study. A horizontal jump-training device (Shuttle System, Contemporary Design Co. Glacier, WA) with rubber elastic cords providing resistance was used to modify landing in 17 people. The device consists of a low friction moveable horizontal sled supporting the body, and a foot-plate that is used by the subject to perform a modified jump and land sequence. We manipulated the device with an electromagnet to hold the participant in the “height” of the jump. After preparing the pressure sensor, the electromagnet was released allowing the sled to move at a speed determined by the elastic resistance, returning to the starting place, and loading the participant's leg in a landing manner. Each participant completed three trails of each type of landing. Two styles of landing (hard -using a stiff knee; soft -using a bent knee) from 30 cm on the horizontal device and landing from steps of 33.5, 28, and 22 cm with similar instructions of landing styles were completed. These activities were counter balanced within the ground and horizontal groups. The impact force applied to the subjects' foot was measured via a pressure platform (Tekscan, Inc., Boston, MA) placed on the floor and on the foot-plate of the horizontal device. Impact force of landing, normalized to body weight was compared between ground heights and horizontal landing, and between landing styles. There were no significant interactions among landing style and height. There was a significant difference between the impact force for landing style (F_{3, 14}=79.64, p= .000) with a lower impact during the soft landings and height (F_{3, 14}=10.43, p= .000) with a lower impact during the horizontal landing. There was no effect for gender (F_{1, 14}= .364, p= .556). The reduced normalized landing impact force on the horizontal training device supports the use of horizontal training in progressive rehabilitation. In addition, to instruct patient in landing techniques makes it possible to reduce the impact force acting on the body during landing.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-111–S-112.

Effects Of Tri-Phasic Oral Contraceptives On Risk Factors On Anterior Cruciate Ligament Injuries In Recreationally Active Females

S Aronson ¹, LC Olmsted ¹, J Hertel ¹

Abstract

Women are 2–8 times more likely to tear their anterior cruciate ligament (ACL) than men. Reproductive hormone levels throughout the menstrual cycle and their effect on risk factors for ACL injury such as altered neuromuscular performance has been previously examined. To date, no studies have focused on neuromuscular performance associated with ACL injury in women taking oral contraceptive pills (OCP). Since reproductive hormone levels stay relatively constant across the menstrual cycle in OCP users, one hypothesis is that neuromuscular performance would not change. The purpose of this study was to examine potential neuromuscular performance risk factors for ACL injury in OCP users. Eight recreationally active females taking tri-phasic OCP with a mean age of 20.25 ± .71 years, mean mass 58.52 ± 6.55 kg and mean height 163.83 ± 9.30 cm participated in this study. Knee joint laxity, quadriceps and hamstring strength, knee joint position sense and postural control were assessed weekly across the course of one menstrual cycle, corresponding to mid-week of subjects' OCP regimen. Repeated measures ANOVAs were calculated for the four dependent variables. Post-hoc pair-wise comparisons were calculated when significant differences were found. Alpha level was set a priori at 0.05. Significant differences were found in strength measures of peak torque at speeds of 60 °/s and 120 °/s (F = 3.51, p = 0.03; F = 3.40, p = 0.04) and average power at 120 °/s for knee flexion (F = 3.10, p = 0.05). Subjects performed at higher peak torque and average power values earlier in the cycle. Significant differences were also found with joint position sense testing at 15 ° (F = 4.97, p = 0.009). Subjects had smaller joint repositioning error towards the end of the cycle. There were no significant differences for postural control and knee joint laxity. The results of strength and joint repositioning measures in the present study were unexpected due to consistently low hormone levels in OCP users. Changes in strength were most notable during the week subjects were menstruating. Subjective menstrual symptoms reported by the subjects may have been the cause of the strength deficits. Changes in joint repositioning error at 15 ° are in agreement with previous studies examining healthy subjects suggesting a learning effect with repeated testing. Our results suggest possible correlations between subtle changes in reproductive hormones and neuromuscular components. Further research should focus on mechanisms by which reproductive hormones affect neuromuscular performance variables across the menstrual cycle on OCP users and non-users.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-113.

The Effects Of Isokinetic And Functional Fatigue On Dynamic Stability During Jump Landings

EA Wikstrom ¹, ME Powers ¹, MD Tillman ¹, MB Horodyski ¹

Abstract

It is well accepted that neuromuscular control plays a major role in dynamic joint stability and the body's inherent protection from injury. It is also well accepted that neuromuscular fatigue can impair this control and stability. In many studies, variables such as proprioception and kinesthesia were assessed when fatigue was induced isokinetically using open kinetic chain movements. It is possible that fatigue induced in this manner does not represent the fatigue experienced during athletic competition. Thus, the purpose of this study was to compare the effects of an isokinetic fatigue protocol (IFP) to a functional fatigue protocol (FFP) using measures of dynamic stability. Twenty healthy male (n=8, age=21.8±1.4 yr, ht.=180.6±7.6 cm, mass=74.1±1 kg) and female (n=12, age=22.2±2.1 yr, ht. =169.3±9.8 cm, mass=62.5±10.1 kg) subjects were assessed for vertical, anterior/posterior, and medial/lateral time to stabilization (TTS), peak vertical ground reaction force (GRF), and knee and ankle kinematics following a jump landing. Each subject completed three jump landing trials requiring them to perform a two-legged jump at 50% of their maximum jump height to the center of a force plate placed 70-cm from the starting position. Subjects were instructed to utilize a single-leg landing on the preferred leg and to stabilize quickly and remain motionless for 20-sec. Immediately following, each subject completed either an IFP consisting of continuous concentric plantar flexion and dorsiflexion contractions at 30°/sec and 120°/sec, or a FFP consisting of a series of agility and plyometric drills. Fatigue was defined as either a 50% decrease in plantar flexion and dorsiflexion peak torque or a 50% increase in time to complete the FFP following an initial maximum effort run through the course. Immediately following fatigue, three trials of the landing task were again performed. Subjects returned one-week later to complete the remaining fatigue protocol under identical testing conditions. The order of the fatigue protocols was randomly assigned and counterbalanced. Separate 2 × 2 (Protocol × Time) analyses of variance with repeated measures revealed significant Time main effects for both vertical TTS (F_1,19=9.17, p=.007) and GRF (F_1,19=9.59, p=.006), as post-test values were significantly greater than pre-test values. No differences were observed in any of the measures when comparing the two fatigue protocols. The results of this study suggest that some measures of dynamic stability can be affected by lower extremity fatigue. The results also suggest that fatigue induced isokinetically can represent fatigue experienced during a more functional task.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-113.

The Effects Of Hamstring Delayed Onset Muscle Soreness On Time To Stabilization From A Jump-Landing

KA Smink ¹, ME Powers ¹, MD Tillman ¹, MB Horodyski ¹

Abstract

Dynamic joint stability is an essential component of athletic performance. If deficits in dynamic stability exist, the athlete may be unable to perform at a competitive level and may be prone to injury. The microtrauma that occurs during resistance and other types of exercise, generally referred to as delayed onset muscle soreness (DOMS), induces changes in the local tissue similar to those seen following macrotrauma. The purpose of this study was to identify whether hamstring DOMS would impair dynamic stability as measured by time to stabilization (TTS) following a jump-landing procedure. Thirty college-aged (age = 21.8±1.5 yr., ht. = 171.5±8.6 cm, mass = 67.4±9.7 kg) subjects free from knee and/or hamstring injury within the past six months participated. Additionally, subjects were excluded if they had participated in lower extremity weightlifting exercises within the past six months. Each subject was randomly assigned to one of two treatment groups (DOMS or control). DOMS was induced using a protocol that consisted of 6 sets of 10 eccentric repetitions performed on a prone hamstring-curl exercise device. Participants in the control group were not subjected to the DOMS protocol. The TTS measurement was derived using a jump-landing procedure onto a Bertec (Bertec Corporation, Columbus, Ohio) tri-axial force plate. DOMS was monitored using hamstring flexibility, pressure pain threshold (PPT), and passive range of motion pain threshold (PROMPT) at baseline, 48-h, and 96-h post. TTS measurements were also performed on both groups at each time period. Separate two-way mixed design analyses of variance (P<.05) were performed for TTS in the vertical plane (Fz), as well as medial/lateral (Mx), and anterior/posterior (My) moments between the groups at each of the measurement points. The level of DOMS was significantly different from the baseline at each of the time points in the DOMS group. No significant interactions were noted for each of the three TTS measures. The results of the present study suggest that dynamic joint stability, as measured by TTS after a jump landing, is not influenced by exercise induced hamstring injury. Despite the physical markers indicating the presence of DOMS in our subject population, there was no influence on TTS. Future research needs to consider the issue that the dynamic task presented here combines the synergistic use of multiple joints and muscles to be executed. Incorporation of an entire lower extremity fatigue protocol or multiple muscle DOMS model could elicit different results.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-113–S-114.

Functional Fatigue Decreases Leg Spring Stiffness During Drop Landings

NMG Martin ¹, HL Sanderson ¹, RJ Schmitz ¹, DH Perrin ¹, SJ Shultz ¹, MA Watson ¹

Abstract

This study determined if functional fatigue influenced leg spring stiffness during a double-leg drop landing. Thirty-five recreationally active, college students (16 males, 19 females, 22.7±3.3 yrs, 173.1±8.8 cm, and 69.6±10.8 kg), were instructed to perform 5 double-leg drop landings from a 60 cm box. Subjects were then instructed to run as fast as possible through a timed agility course consisting of forward running, backward running, and side shuffling (128m total). A maximal vertical jump was completed following every other trial to help confirm fatigue. Subjects were allowed no longer than 5s between trials and were deemed fatigued when the trial time reached 150% of their first trial time on 3 consecutive trials OR when 30 trials were completed. Following the final trial subjects repeated the drop landings. To assess between day reliability, 18 subjects repeated this protocol at least 72 hours later (8 males, 10 females, 22.0 ± 2.5 yrs, 172.9 ± 9.9 cm, 66.1 ± 10.6 kg). Vertical ground reaction force (vGRF) for each drop landing, time for each trial and jump height for every other trial were recorded. Leg spring stiffness was calculated by dividing vGRF by center of mass (COM) displacement. Repeated measure ANOVAs were performed for vGRF, leg spring stiffness, and COM displacement (pre to post fatigue); as well as time and maximal vertical jump height (initial vs. final). ICC_2,K (SEMs) assessed day-to-day performance consistency in response to this fatigue protocol. Significant decreases were found between pre-fatigue (268.5±84.5 N*m⁻¹) and post-fatigue (220.5±62.8 N*m⁻¹) leg spring stiffness; as well as between initial (0.44±0.11m) and final (0.30±0.13m) maximal vertical jump height. Significant increases existed for vGRF (4449±1051 N vs. 4784±1070 N), COM displacement (−0.25±.04 m vs. −0.33±.05m), and initial to final trial time (23.5±2.9 s vs. 36.3±6.2 s). These responses were consistent across repeat test days for pre and post fatigue measures; ICC_2,K = 0.93 (23.3 N*m⁻¹) and 0.82 (30.0N N*m⁻¹) for leg spring stiffness; 0.88 (396.1N) and 0.94 (301.6N) for vGRF; 0.85 (0.01m) and 0.75 (0.03m) for COM displacement, respectively. These findings suggest that functional fatigue reliably decreases leg spring stiffness during drop landings. Thus fatigue may alter musculoskeletal biomechanics through decreased ability to control the deceleration phase of landing, specifically decreasing leg spring stiffness. As leg spring stiffness decrements have been suggested to explain injury incidence, this study suggests that fatigue may alter leg spring stiffness in a way that increases injury risk.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-114.

Isokinetic And Functional Fatigue Protocols Have Similar Effects On Balance

JA Tymkew ¹, C Jacobs ¹, CG Mattacola ¹, TL Uhl ¹, TR Malone ¹

Abstract

Muscular fatigue has been induced using both isokinetic and functional protocols. The efficacy of the fatiguing protocol is often examined by comparing balance before and after exercise. Comparisons between different fatiguing protocols have not been examined. The purpose of this study was to compare the effects of isokinetic and functional fatigue protocols on balance. Two separate repeated measures 2×10 ANOVAs (fatigue protocol × test trial; p<0.05) assessed sway differences from baseline in the anterior-posterior and medial-lateral direction (in). The two levels of fatigue protocol were isokinetic and functional; the 10 levels of test trials were baseline and post-fatigue trials 1–9. Isokinetic testing was performed in Wenner-Gren Biodynamics Laboratory and functional testing was performed in the College of Health Sciences Musculoskeletal Laboratory. Sixteen, healthy subjects (8 males and 8 females, age=22.69 ± 2.98 years, ht=173.43 ± 8.65 cm, wt=67.76 ± 7.46 kg) volunteered for this study. On each testing day, subjects balanced on the NeuroCom Balance Master^® (Clackamas, OR) to obtain baseline sway distances, then completed one of the two muscular fatigue protocols (the knee isokinetic test or the functional test). After completion of the respective fatigue protocol, subjects balanced on the NeuroCom Balance Master^® for nine time intervals over three minutes (10 seconds balancing, 10 seconds rest). The isokinetic protocol consisted of a knee flexion/extension, concentric/concentric exercise at 180°/s until peak torque dropped 50% below maximum for three consecutive trials. The functional test consisted of an anaerobic exercise protocol, which included forward sprinting, retro running, side shuffling, and cariocas. Subjects performed trials until their time to completion increased 50% above their initial trial. Thirty seconds rest was provided between trials. The repeated measures ANOVAs revealed no main effect for fatigue protocol in the anterior-posterior direction (F_1,15=1.991, p=.179) or the medial-lateral direction (F_1,15=1.205, p=.290). Results revealed a main effect for time in both the anterior-posterior (F_9,135=7.079, p=.000) and medial-lateral (F_9,135=3.804, p=.000) direction. A Bonferroni Holm Post-Hoc analysis (p<.05) indicated that anterior-posterior post-fatigue trial 1 (11.30 ± 4.28), trial 8 (5.96 ± 4.92), and 9 (5.02 ± 4.64) were significantly different from baseline and medial-lateral post-fatigue trials 1 (5.03 ± 1.63), 3 (2.79 ± 2.79), and 8 (3.15 ± 2.63) were significantly different from baseline. The two fatigue protocols, isokinetic and functional, had similar effects on balance. It appears that either an isokinetic or a functional protocol is effective and thus gives the clinician flexibility in application.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-114–S-115.

Acute Rhabdomyolysis In A Female Collegiate Soccer Player

CG Recinella ¹, DM Santangelo ¹, PM Malloy ¹

Abstract

A 20-year-old NCAA Division I female soccer player complained of extreme soreness in both quadriceps after beginning off-season training. The first day of workouts consisted of leg press, squats, and lunges to fatigue at a maximum weight. The athlete reported to the athletic training room complaining of soreness in both quadriceps and was treated with ice, mild stretching and a compression sleeve. The athlete participated in the second day of workouts consisting of running with weights, sprinting, and jumping lunges. The athlete returned to the athletic training room complaining of increased pain and swelling. She had no history of difficulty with workouts, dehydration, heat illness, or anemia. The athlete has no history of drug or alcohol use.Initial signs and symptoms presented as delayed onset muscle soreness (DOMS). On day one of conditioning there was pain with palpation, anatalgic gait, and decreased knee flexion. After day two, the signs and symptoms progressed with decreased range of motion (ROM), increased pain and generalized swelling in thighs bilaterally. She also reported hematurea and intense quad pressure with the left quad feeling as if it was “going to explode”. The athlete was referred to the team physician for further evaluation.Differential Diagnoses consisted of extreme bilateral quad strain, dehydration, exertional rhabdomyolysis, and bilateral compartment syndrome of thighs. Laboratory results reported a creatinine level of 1.6, hematocrit at 40.0 and Creatinine Phosphokinase (CPK) levels of 1,128,170 U/I serum where normal levels are 20–200 U/I serum. A urinalysis revealed 1+ albumin. Rhabdomyolysis was confirmed.After evaluation by a team physician, the athlete was immediately sent to the emergency room for IV fluids. The athlete had oliguria and CPK levels were significantly elevated placing increased stress on her kidneys with risk for renal failure. A foley catheter was inserted to monitor urine production and the athlete was taken to the CCU in case emergency dialysis was needed. Additionally, anterior compartment syndrome was suspected but no course of action was taken due to unstable renal function. Once the athlete's CPK levels dropped the athlete's condition was considered stable and she underwent bilateral compartmental release of the thighs. Proximal and distal three inch incisions were made on the lateral side of both thighs. The athlete had follow-up surgery five days later to close the fascia. The athlete remained in the hospital for a total of nine days to monitor kidney function. Upon release, the athlete used a walker for 3–4 days then began to walk on her own for short distances. Rehabilitation consisted of quad sets, straight leg raises, ankle pumps, ROM exercises, and limited walking for two months. She then was released to begin more aggressive rehab by adding weights and repetitions to rehabilitation exercises. She began jogging at four months post surgery. The athlete complained of rapid fatigue and soreness of bilateral quads when increasing difficulty of workouts. After six months of re-conditioning she was cleared by the surgeon and team physician to participate in pre-season soccer at 40% exertion. She was instructed to increase percentage as tolerated. During pre-season she had slight swelling of the right anterior compartment and had to be restricted for 2–3 days. During the season, the athlete experienced a muscle herniation through the fascia slit of the distal right thigh causing some discomfort but was not limited. The athlete was able to complete her senior year of soccer without restrictions. Experiencing DOMS is expected during an athlete's training, but intense soreness with decreased ROM and apparent swelling of any muscle group is not. Cases of exertional rhabdomyolysis have been noted in the military during boot camp, marathon runners, extreme weightlifters, and in unconditioned persons. This case is unique because she was a healthy, conditioned athlete who had been participating in division I collegiate workouts for over two years with no previous problems. Also, no inherent pre-disposition was determined by a geneticist. The onset of her condition was very rapid and severe resulting from only two days of running and lifting. The team had a four week break between the fall season and the first day of workouts with no structured fitness maintenance program. This lapse in workouts may have put the team at risk for exertional injuries and illnesses. Rhabdomyolysis is not commonly seen by the athletic training population. Increased awareness among athletic trainers will result in early recognition and diagnosis preventing the fatal secondary conditions that can develop. The risk for rhabdomyolysis may be decreased with smart conditioning and prevention education.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-115.

Acetaminophen Extended Release Versus Ibuprofen In Treating Post-Marathon Muscle Soreness

BJ Lavins ¹, J Nick ¹, K Cooper ¹, C Quigley ¹, SA Silber ¹, DL Bowen ¹

Abstract

Acetaminophen (APAP) and ibuprofen (IBU) are widely used to treat post-exercise muscle soreness, but their effects have not been compared in trained distance runners after a long-distance run. This double-blind, parallel-group, non-inferiority study compared APAP and IBU in treating post-marathon muscle soreness. Eligible subjects (N = 497) were males or females ≈18 years of age who had completed the marathon and had not used over-the-counter analgesics during the race or confounding medications for at least 1 day or 5 half lives before the marathon. Female subjects were required to be non-pregnant, non-lactating, and using an acceptable form of contraception. Subjects were ineligible if they had: a previous diagnosis of osteoarthritis requiring analgesic therapy; major concurrent medical illness; a history of cardiovascular disease, heat injury, or collapse during a running or endurance event; known hypersensitivity to the study medications; appeared to need medical attention during the race; or had post-race baseline muscle soreness scores <4 on a scale of 0 (no muscle soreness) to 10 (maximal muscle soreness). All subjects provided informed consent. Subjects were randomized to receive APAP Extended Release (APAP ER) 1300 mg tid (3900 mg/d) or IBU 400 mg tid (1200 mg/d). Both study medications were administered orally for 5 days. Assessments were recorded twice per day (in the morning and evening) by telephoning an interactive voice response system. The primary efficacy variable was the average change from baseline in muscle soreness for both the morning and evening assessments. APAP ER was considered to be non-inferior to IBU if a one-sided, 95% confidence interval of the difference in adjusted means was less than the non-inferiority boundary defined as a relative effect size of 0.35. Of 497 randomized subjects, 483 were evaluated for safety and 377 for efficacy. Mean baseline muscle soreness was 7.6 (standard error [SE], 0.11) for both groups. The average change in muscle soreness from baseline to day 5 (morning and evening) was −3.92 (SE 0.117) for the APAP group and −4.19 (SE 0.120) for the IBU group. The one-sided 95% confidence interval (CI) (-infinity to 0.4640) of the difference in adjusted means was less than the non-inferiority limit (0.5717), implying that APAP ER was not inferior to IBU. Twenty-four subjects (5.0%) had at least 1 treatment-emergent AE (TEAE), including 11 subjects (4.5%) in the APAP group and 13 (5.4%) in the IBU group. As APAP met the predefined non-inferiority criteria, it is comparable to IBU in the treatment of post-marathon muscle soreness.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-115.

Threshold Frequency Of An Electrically Induced Cramp Increases Following A Fatiguing Exercise

MB Stone ¹, JE Edwards ¹, ML Cordova ¹, CD Ingersoll ¹, JP Babington ¹, J Chen ¹

Abstract

A recent hypothesis regarding the genesis of exercise-associated muscle cramp is that cramp develops as a result of an abnormal, heightened increase in a-motoneuron activity due to fatigue. The frequency of stimulation at which an electrically induced cramp originates is termed the threshold frequency (TF). A change in TF is thought to represent one's propensity to cramp. If fatigue is a factor in the genesis of cramp, the TF of a fatigued muscle should shift from a previously established baseline. The purpose of this study was to determine the effect of local muscle fatigue on TF of electrically induced muscle cramp. A 2 × 2 repeated measures design was used for this study. The independent variables were test (pre- and post-) and condition (control and fatigue). The dependent variable was TF of an electrically induced cramp of the flexor hallucis brevis. Sixteen healthy subjects were recruited and counterbalanced assigned to testing order. A cramp was induced to determine baseline TF. For control, subjects then rested in a supine position for 30 min followed by another cramp induction to determine post-TF. For fatigue, after the pre-TF was determined subjects performed 5 bouts of great toe curls to failure at 60% 1-RM with 1 min rest between bouts. Immediately following the 5^th bout the post-TF measurement was taken. Of 16 subjects, 5 were excluded due to the fatigue criteria not being achieved post-exercise. A condition (fatigue/control) × test (pre/post) repeated measures ANOVA revealed a test by condition interaction for TF (F_{1, 10} = 37.655, P < 0.001). Simple main effects testing showed post-fatigue TF (32.9 ± 11.7 Hz) was significantly greater than pre-fatigue TF (20.0 ± 7.7 Hz; t₁₀ = −6.745, P < 0.001). The degree of local muscle fatigue realized in this study caused an increase in the TF of an electrically induced muscle cramp.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-116.

Within And Between Test Measurement Consistency Obtained From A Custom Reflex Testing Device

SJ Shultz ¹, TC Windley ¹, AS Kulas ¹, RJ Schmitz ¹, TC Valovich McLeod ¹, DH Perrin ¹

Abstract

The anterior cruciate ligament plays a sensory role in knee joint stabilization, providing feedback when excessive loads or joint motions are perceived. This study determined the reliability of a custom device (patent pending) to examine neuromuscular reflex sensitivity in response to anterior tibial loading. Measures included reflex time, reflex amplitude and knee extension torque within day (pre vs. post test baseline) and between days (pre and post baseline tests repeated 24–48hrs apart). Twenty subjects (10 M, 10 F; 24±4yrs, 74±21kg, 168±10cm) were positioned side-lying in a modified ligament-testing device. A reflex hammer attached to the device via a steel mounted frame elicited a knee extensor reflex while anterior-directed loads (20N, 50N, 100N; counterbalanced) were applied to the posterior tibia between pre and post baseline conditions. A load cell on the reflex hammer triggered data acquisition and recorded the tap force (Tap_F = N). Surface electromyography attached to the rectus femoris, medial and lateral vastii and hamstring muscles recorded mean quadriceps (Q) and hamstring (H) reflex time (R_Time = ms) and amplitude (R_Amp = %MVIC) from 5 trials at each condition. A load cell on the anterior shin, positioned 23cm from the joint line, was used to calculate the subsequent knee extension moment (KE_Mom = Nm/kg). Means±sd for pre and post baseline measures on day 1 & 2 ranged from 19.4±6.5 – 22.6±7.9N (Tap_F), 19.2±3.2 – 20.1±3.5ms (Q R_Time), 172.6±135.8 – 230.9±198.7%MVIC (Q R_Amp), 21.9±6.2 – 25.6±7.2ms (H R_Time), 53.6±51.8 – 63.6±59.9%MVIC (H R_Amp), and 0.11±0.06 – 0.13±0.06Nm/kg (KE_Mom). Day to day reliability coefficients (ICC_(2,k) ±SEM) for pre and post baseline measures of Tap_F (pre=.87±2.5N; post =.80±2.9N), Q R_Time (pre=.85±1.4ms; post=.89±1.1ms) and R_Amp (pre=.94±49.3%; post=.94±50.5%), H R_Time (pre=.77±3.1ms; Post=.72±3.8ms) and R_Amp (pre=.86±22.8%MVIC; post=.89±20%), and KE_Mom(pre=.90±0.2Nm/kg; post=.92±0.02Nm/kg) confirmed that consistent measures can be obtained from subjects on repeated test days. Within test reliability coefficients, comparing baseline measures pre and post loading trials, for Tap_F(Day₁=.90±2.4N; Day₂=.90±2.1N), Q R_Time (Day₁=.95±0.8ms; Day₂=.91±1.1ms) and R_Amp (Day₁=.90±63.2%; Day₂=.97±33.6%), H R_Time (Day₁=.95±1.4ms; Day₂=.81±3.1ms) and R_Amp (Day₁=.98±8.7%MVIC; Day₂=.96±11.9%), and K E_Mom Day₁=.91±0.02 Nm/kg; Day₂=.93±0.02Nm/kg) confirm the stability of these measures across repeated tests within the same session. With the reliability and precision of this research model confirmed, future research will use this device to examine the effects of knee injury risk factors (e.g. sex, fatigue, joint laxity) on neuromuscular reflex sensitivity in response to joint loading. Supported by a faculty grant from the University of North Carolina at Greensboro

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-116.

Reliability Of Three Different Strength Testing Protocols For Hip Abduction, Extension And External Rotation

TJ Hawkey ¹, SD Halverson ¹, DA Padua ¹, KM Guskiewicz ¹

Abstract

The assessment of hip abduction, external rotation, and extension strength are important components of lower extremity evaluation. However, a reliable method for assessing these measures has not been examined. Therefore, the purpose of this study was to examine the intra-session reliability of different methods to assess hip abduction, external rotation, and extension strength. Twenty healthy participants volunteered for this study. Strength of the kicking dominant leg was assessed for: hip abduction, hip extension, and hip external rotation. Strength was assessed using an isokinetic and hand-held dynamometer. Isokinetic testing was performed using concentric-eccentric and isometric protocols, separately. Hand-held dynamometer testing incorporated only isometric contractions using a make-test. Peak and average values were recorded for each strength measure. Participants performed three trials for each of the strength measures. Intra-session reliability was assessed using ICC (2,1) for each of the strength measures. The concentric-eccentric isokinetic protocol demonstrated excellent reliability (ICC > .90) for hip abduction and external rotation. However, hip extension values were less reliable with ICC values ranging from .72 to .89. Isometric testing on the isokinetic dynamometer revealed excellent reliability (ICC > .91) for all strength measures. Hand-held dynamometer strength measures also demonstrated excellent reliability (ICC > .90) for the strength measures, except for average hip extension values (ICC = .71). These findings demonstrate that average and peak strength for hip abduction, extension, and external rotation can be reliably measured using concentric-eccentric and isometric protocols using isokinetic and hand-held dynamometers. Isometric testing using the isokinetic and hand-held dynamometer demonstrated similar reliability, except that average hip extension values were less reliable using the hand-held dynamometer compared to the isokinetic dynamometer. Hip extension was also less reliable than hip abduction and external rotation measures during concentric-eccentric isokinetic testing. Thus, the reliability of hip extension strength values appears to differ depending on the assessment method. However, it should be noted that hip extension strength measures demonstrate acceptable reliability for all strength assessment methods performed in this study. The strength assessment methods used in this study deviate from the manufacturer's recommended testing position. Subjects were positioned for maximal body stability and isolation of hip joint movement. We believe that modified subject positioning improved the reliability of these measures. These results may be considered when assessing hip abduction, external rotation, and extension strength.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-116–S-117.

Between-Day 3D Kinematic Measurement Consistency During Lower Extremity Perturbations

RJ Schmitz ¹, SJ Shultz ¹, AS Kulas ¹, TC Windley ¹, DH Perrin ¹

Abstract

The reliability of a new device that measures neuromuscular response to a lower extremity perturbation has previously been established. However, it is not known if this neuromuscular response is accompanied by consistent kinematic patterns. This study determined the reliability of this perturbation device in providing consistent kinematic displacements as the result of internal and external rotation perturbations. Twenty subjects (10M,10F; 24.9±4.1yrs, 171.5±7.7cm, 73.6±17.2kg) completed an identical test protocol on 2 days. During each test session an electromagnetic tracking system and a non-conducting force plate monitored kinematics and kinetics while a lower extremity perturbation device produced 10 internal (IRP) and 10 external (ERP) rotation (random order) perturbations of the femur on the weight-bearing tibia at 30° of knee flexion. Hip flexion (HF), hip abduction (HA), hip rotation (HR), knee flexion (KF), knee abduction (KA), and knee rotation (KR) total joint displacements (TJD) were computed as averages from the 10 IRP and ERP trials. TJD was calculated from the initial joint position to the peak joint displacment during the single leg weight bearing phase of the perturbation. Extension, adduction, and internal rotation of the distal segment of the joint were defined as postive values. IRP Means ± sd for day 1 and day 2 TJD's were: HF_TJD −5.0 ± 4.8° & −5.4±3.5°; HA_TJD −1.5±2.8° & −1.3±2.4°; HR_TJD −11.1±6.3° & −12.3±5.1°; KF_TJD 2.7±6.7° & 1.8±4.9°; KA_TJD 2.5±3.6° & 3.0±2.1°; and KR_TJD −7.0±5.7° & −7.8±3.9°. ERP Means±sd for day 1 and day 2 TJD's were: HF_TJD −6.0±3.3° & −6.9±3.2°; HA_TJD −3.1±2.1° & −3.0±2.4°; HR_TJD 6.7±3.6° & 7.0±3.4°; KF_TJD 2.0±3.4° & 1.4±4.4°; KA_TJD −3.7±1.3° & −3.4±1.3°; and KR_TJD 7.6±2.3° & 6.8±2.5°. Reliability coefficients (ICC_(2,k) ± SEM) for between day measures of HF_TJD (.79±2.2°), HA_TJD (.52±1.9°), HR_TJD (.87±2.3°), KF_TJD (.80±3.0°), KA_TJD (.84±1.4°), KR_TJD (.85±2.2°) for IRP, and between day measures of HF_TJD (.69±1.8°), HA_TJD (.67±1.4°), HR_TJD (.79±1.6°), KF_TJD (.88±1.5°), KA_TJD (.80±0.6°), KR_TJD (.82±1.0°) for ERP, confirmed moderate to strong between day consistency in kinematic responses to this lower extremity weight bearing perturbation. With the reliability and precision of the kinematic measures confirmed, future work will investigate the joint kinetics during these internal and external perturbations.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-117.

Time-To-Boundary: A Novel Postural Control Assessment In Single Leg Stance

J Hertel ¹, LC Olmsted ¹

Abstract

A novel approach to quantifying stability in single leg stance is assessment of time-to-boundary (TTB) of center of pressure (COP) excursions. TTB measures estimate the time required for the COP to reach the boundary of the base of support if it were to continue on its current trajectory and velocity, thus assessing spatiotemporal characteristics of postural control. Our purpose was to examine the reliability of TTB and traditional COP-based measures, and the correlations between these measures. Twenty-four young adults completed three 10-second trials of single limb quiet standing on each limb. Traditional measures included standard deviation, velocity, and range of frontal (X) and sagittal (Y) plane COP excursions. For each data point, the instantaneous COP position and velocity were used to calculate TTB. For example, if COP X_i was moving medially, the distance between COP X_i and the medial boundary of the foot was calculated and divided by the corresponding velocity of COP X_i to determine the time required for COP X_i to reach the foot's boundary if it continued without deceleration. A time series of corresponding TTBX and TTBY measures was generated and used to calculate the resultant TTB (TTBR). A typical TTB series shows a sequence of peaks and valleys with the bottom of each valley representing a change in direction of COP. We sampled TTB measures at the valleys in each trial. TTB variables were the absolute minimum, mean of minimum samples, and standard deviation of minimum samples in the X, Y, and resultant directions. For each measure, ICCs were calculated for the 3 repeated trials on each limb. ICCs for traditional measures ranged from .35–.80 and .40–.74 in the frontal and sagittal planes respectively, while those for TTB measures ranged from .34–.81, .50–.87, and .54–.85 in the frontal, sagittal, and resultant planes. Bivariate correlations within traditional measures ranged from .66–.95 and .35–.97 in the frontal and sagittal planes, and from .45–.95, .70–.96, and .73–.95 for TTB measures in the frontal, sagittal, and resultant planes. Correlations between traditional and TTB measures ranged from .11–.90 and .03–.77 in the frontal and sagittal planes. The reliability of TTB measures is comparable to traditional measures. Correlations between TTB and traditional measures were weaker than those within each category of measures indicating that TTB measures capture different aspects of postural control than traditional measures. TTB measures provide a unique method of assessing spatiotemporal characteristics of postural control during single limb stance.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-117–S-118.

Validating The Single-Leg Squat Test As A Functional Test For Hip Abduction Strength

MA DiMattia ¹, AL Livengood ¹, TL Uhl ¹, CG Mattacola ¹, TR Malone ¹

Abstract

The single-leg squat (SLS) is a functional test commonly used to assess lower extremity strength. The purpose of this study was to determine the correlation between hip abduction strength and maximal hip adduction angle during the performance of a SLS. A secondary purpose was to evaluate the validity of a clinical observational technique to assess SLS performance as compared to a two-dimensional kinematic analysis. Fifty subjects (age, 24.32 ± 4.78 years; height, 171.64 ± 11,16 cm; mass, 74.84 ± 21,82 kg; 26 males, 24 females) with no lower extremity injuries volunteered for this study. We used a single-measure, concurrent validity study design. Subjects' hip abduction strength was measured on the dominant leg in a side-lying position using a hand-held dynamometer. The average of three trials was normalized to the subjects' bodyweight. We placed reflective markers on the lateral shoulder, both ASIS, greater trochanter, lateral knee, lateral malleolus, heel, and fifth metatarsal head of the dominant leg. Subjects performed a SLS with arms forward flexed and the non-dominant leg flexed to approximately 45° at the hip and 90° at the knee. The subject then squatted down to 60° of knee flexion and returned to the start position within 6 sec. Three SLS squat trials were recorded by the motion analysis system and concurrently graded by two clinicians using pre-determined criteria that assessed hip flexion, hip adduction, and knee valgus. Two-dimensional joint angles were exported from the motion analysis system. Results demonstrated a low correlation between hip abduction strength and measured hip adduction during the SLS (r = −.12, p=.40). The validity of the clinical observation technique revealed low sensitivity (26–68%) but high specificity (62 – 89%). We also found a high negative predictive value (71 – 92%) and a low positive predictive value (23 – 54%), which was expected because we sampled from a healthy population. Agreement between raters for identifying excessive (>10°) hip adduction and knee valgus was 71% (k= .02) and 67% (k=.28) respectively. We conclude that a SLS does not correlate highly with hip abduction strength and further research on the SLS and quadriceps strength is an appropriate next step. We also conclude that novice clinicians are able to visually determine when the knee and the hip are relatively straight during a SLS but that we are not able to determine excessive (>10°) movement in the frontal plane occurring at the hip and the knee. Finally, clinical decisions simply based upon visual observations without objective and valid measures should not be used to base assessments on patient functions.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-118.

Repeated Administration Of The Concussion Resolution Index Demonstrated A Practice Effect In Non-Concussed Subjects

A Reinhart ¹, SC Livingston ¹, JT Barth ¹, SM Zinder ¹, CD Ingersoll ¹

Abstract

The assessment and management of sports-related concussions can be aided by computer-based neuropsychological tests such as the Concussion Resolution Index (CRI). The potentially confounding issue of practice effects on test outcomes make interpretation of these tests more challenging and complex. The purpose of this study was to determine whether subjects' scores on the CRI would change over time with repeated administration of the test, despite using alternate forms of the test. A repeated measures design was used. Baseline CRI tests were administered to subjects at Longwood University (Farmville, VA). One week following the initial testing, subjects underwent repeated testing at regular time intervals. The CRI reports scores for five test indices, which include: Simple Reaction Time (SRT), SRT Errors, Complex Reaction Time (CRT), CRT Errors, and Processing Speed (PS). Subjects were tested on 6 separate occasions using alternate test forms. Thirty-two subjects, ages 18 to 25 years, from Longwood University participated in the study. Significant practice effects were demonstrated with SRT (F_5,31=3.7, P=.003), CRTE (F_5,31=2.6, P=.028), and PS (F_5,31=20.1, P<.001) indices. There were no statistically significant differences demonstrated in CRT and SRTE indices (P>.05). Comparisons between days of testing reflected significant changes within the CRTE index (test session 3 (3.9±3.3) and 4 (6.5±5.0), and the PS index (multiple test sessions, P<.05). The results support the hypothesis that there are practice effects associated with repeated administration of the CRI despite using alternate forms of the test. Overall, the SRT, CRTE, and PS indices showed significant changes. The use of additional evaluative criteria for concussion assessment and return-to-play decision making is necessary due to the potential learning effects when athletes are administered the CRI repeatedly.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-118.

Knowledge And Direction Of Force Application Effect Head Acceleration

MR Sitler ¹, RT Tierney ¹, CB Swanik ¹, KA Swanik ¹, M Higgins ¹, JS Torg ¹

Abstract

Concussions are potentially life-threatening head injuries often caused by activities within the rules of a sport. The amount of head acceleration in response to force application is important because it has a direct correlation with concussion severity. Concussion prevention strategies have included the contraction of neck muscles prior to force application. Although neck muscle contraction prior to external head loading increases resistance to movement, it has not been studied thoroughly in a physically active population as a means of reducing head acceleration (and risk of concussion). The purpose of this study was to determine the effect of knowledge and direction of force application on head-neck segment kinematic and dynamic stabilization variables responses to an external force application. Forty physically active volunteers participated in the study: males, N = 20, age = 26.3 +4.3 years, height = 177.1 ± 6.1 cm, mass = 84.5 ±11.8 kg and females, N = 20, age = 24.2 ±4.1 years, height = 165.3 ±5.3 cm, mass = 59.0 ±5.1 kg. The study consisted of a two-factor research design with repeated measures. The independent variables were force application (known vs. unknown) and force direction (forced flexion, trapezius I eccentric tension assessed, vs. forced extension, sternocleidomastoid eccentric tension assessed). The dependent variables were selected kinematic and EMG variables, head-neck segment stiffness (Newtons per degrees), and head-neck segment flexor and extensor isometric strength (pounds). An external load of 50 N was applied to the participants' head-neck segments using a pulley system. The standardized force applications resulted in forced flexion or forced extension. Statistical analyses consisted of multiple multivariate analyses of variance, analyses of variance, and t-test, as well as follow-up univariate analyses of variance and t-tests (p ≤ .05). The results revealed that knowledge of force application significantly reduced head-neck segment acceleration (11% reduction) and displacement (33% reduction). Head-neck segment stiffness was significantly greater (25%) during known vs unknown forced extension. Acceleration and displacement were also significantly less (16% and 8%, respectively) when individuals were forced into flexion versus extension. Although there were no significant differences between sternocleidomastoid or trapezius I EMG (peak or area), isometric strength was significantly greater (41%) during forced flexion than forced extension. The results indicate that neck muscle preactivation can reduce head acceleration and should be prescribed to reduce the risk of concussion. Resistance training should focus on the ventral head-neck segment muscles because they are less capable of resisting head-neck extension resulting in greater risk of concussion.

J Athl Train. 2004 Apr-Jun;39(Suppl 2):S-118–S-119.

Intra-Tester Reliability Measurements Of Dynamic Tasks On The Kistler 9287BA Force Plate

DJ Stearne ¹, TM Covassin ¹, CB Swanik ¹, MR Sitler ¹

Abstract

Force plates are precise instruments often used to analyze kinetic data for injury prevention, rehabilitation, and sport performance. However, no research has investigated the reproducibility of force plate data over time when testing dynamic functional tasks. The purpose of this study was to determine the intra-tester reliability of a Kistler 9287BA Multi-Component Force Plate (Kistler Instrument Corp, Amherst, NY) when performing dynamic tasks that require each subject to move onto the force plate. Kinetic data were collected at 1,000 Hz and passed through an integrated amplifier for analysis using BioWare computer software (Kistler Instrument Corp, Amherst, NY) on peak vertical ground reaction force (Fz), peak shear forces in anterior-posterior (Fy) and medial-lateral (Fx) directions, and time to peak in all three directions on test-retest separated by no more than 7 days. Scores were collected for these variables on 14 healthy subjects (6 males and 8 females) (age 25.1 ± 4.9, height 172.9 ± 6.7 cm, weight 70.8 ± 11.2 kg) on the following 5 dynamic tasks: drop jump, drop landing, stop jump, stop landing, and cross-over cut. Center of pressure (COP) displacement area and velocity were then measured on one-legged quiet stance for 5 seconds per trial and processed in the same manner as force measures using the BioWare software package and collected at a sampling rate of 100 Hz. Pearson r correlations were conducted on the average of three trials for each activity on all subjects using the SPSS statistical software (version 11.0). Within task, between day correlations were moderate to high on peak force in Fx, (r = .52–.72), Fy (r =.68–.91), and Fz (r =.63–.93). All correlations for peak force were significant (p<.05) except Fx on drop jump task (p=.06). A low to high correlation was found on time to peak across the 5 tasks in Fx (r =.04–.97), Fy (r=.38–.73), and Fz (r =.20–.65). Results showed moderate correlation in scores for both COP displacement area (r =. 61, p<.05) and COP displacement velocity (r =.60, p<.05) on the one-legged quiet stance task. Although the Kistler Force Plate was found to be a reliable instrument to measure peak forces on dynamic tasks and COP displacement area and velocity in quiet stance, it was less reliable for time to peak force measures. Caution should be used when interpreting data over time because dynamic tasks may require a high degree of coordination and/or training from specific subject samples.

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