Manual Therapy Treatment for Penile Pain- A Clinical Case Report with 6-Month Follow-up

ABSTRACT

Background

Male genital pain, which is neither related to genitourinary nor other obvious pathology, is an uncommon symptom in male patients and not frequently treated using manual therapy. The purpose of this case study is to describe a clinical reasoning process in combination with anatomy-based differential diagnosis and manual treatment for genital pain.

Case Description

A male patient with a 3-week acute onset of genital pain was hospitalized and referred for evaluation and treatment after unsuccessful treatment with medication and acupuncture. Clinical examination was performed indicating a possible nerve entrapment followed by interventions of ligamentous articular strain, high-velocity low-amplitude (HVLA) manipulation, and strain– and counterstain, coupled with soft tissue stretching to lumbar and inguinal areas to address a possible lumbar referral potentially from L1 and/or ilioinguinal nerve entrapment.

Outcomes

After 4 consecutive days of manipulative treatment, pain decreased from 9/10 to 0/10 and the Barthel Index improved from 50 to 95. A 6-month follow-up revealed complete resolution of symptoms with no recurrence.

Discussion

This case illustrates that a detailed history and examination along with a reasoned diagnostic process to determine an appropriate intervention strategy may improve patient care using manual therapy techniques.

Conclusion:

By utilizing a deductive reasoning process related to the penile area, clinicians may better apply manual therapy techniques for successful treatment.

Background

Unexplained penile pain is one of non-etiological chronic pelvic pain syndrome that is related neither to genitourinary nor other obvious pathology [1]. It is diagnosed through elimination of various conditions and requires a clinical reasoning approach [2]. A literature search for English language articles in PubMed and Scopus using keywords of genital pain, penis pain, penile pain, scrotum pain, scrotal pain, manipulation, manipulative therapy, hands-on therapy, and manual therapy demonstrated one article that reported penile pain treated with non-surgical or non-medical interventions [3]. The authors found that in male patients with chronic pelvic pain syndrome, palpation of a trigger point in the pelvic muscles (internally – puborectalis/pubococcygeus, coccygeus; and sphincter ani; and externally – rectus abdominis. external oblique, adductor magnus. gluteus medius, bulbospongiosus, transverse perineal, and gluteus maximus) could reproduce pain in seven pelvic locations: penis, perineum, rectum, suprapubic region, testes, groin and coccyx/buttocks, with the top three being the penis (90.3.%), perineum (77.8%), and rectum (70.8%). The authors thought that by identifying the relationship between the muscle trigger point sites and pelvic pain locations, clinicians would better understand why manual treatment could relieve pelvic pain. A further literature search found that penile pain may be caused by involvement of pudendal, genitofemoral, or ilioinguinal nerves due to lower abdominal surgery, trauma, or bladder stones [4–8]. The clinical manifestations may include burning or radiating pain in the inguinal region and genitalia [6–9]. Genital pain treated via manual treatment has not been frequently reported, particularly with a male patient [3,10]. Thus, this case report describes a process of clinical reasoning leading to diagnosis and successful therapy using manual treatment for penile pain.

Case description

A 54-year-old male patient employed as a farmer (height 167 cm and weight 64 kg) was referred for manual physical therapy with a 3-week history of waking with an acute insidious onset of sharp penile pain, believed to be related to farm activities performed the previous week. He was the father of three children with no history of genetic disease and did not smoke or drink alcohol. The patient reported being healthy with no previous surgery, hospitalization, or sexual dysfunction. Pain was initially tolerable, but the pain level increased to as high as 9/10 and was accompanied by daytime dysuria over the first week. Pain occurred 4–5 times per night, lasting for about 10 min, and gradually subsided. The only position of ease was to kneel into the fetal position with one hand grasping his penis (Figure 1). Two weeks after the onset, the patient was admitted to the hospital due to the effects of penile area pain on bowel and urinary function. The patient stated that he wanted to urinate when the bladder was getting full, and was able to urinate or pass the stool, but was very painful in the penile and scrotum area. He denied any sensory disturbance like tingling and numbness at the anal and buttock areas when the pain occurred. Further, the initial medical examination revealed no tender areas related to the sacrotuberous ligament, ischial tuberosity, inferomedial border of the ischium, or ischiorectal fossa on either side. Active trunk motion of extension and sidebending/rotation to the right aggravated the pain, with flexion relieving the pain mildly. Neurological testing of dermatomes and bilateral cremasteric reflexes were normal. Additionally, blood and urine tests were within normal limits. The X-ray at admission revealed that the patient had a scoliotic left lumbar segment with a left convexity and right rotation (Figure 2). Abdominal ultrasound identified no abnormalities in the genitourinary system, including stones. Magnetic resonance imaging of the penis and scrotum was reported as normal. As a result, he was diagnosed with ‘idiopathic’ penile pain related to chronic pelvic pain syndrome and treated with Ibuprofen and acupuncture for a week, which provided temporary relief for approximately 2 hours each time. Consultation with a manual therapist was then requested and was performed by the principal investigator (YL).

Figure 1.

The patient kneeled down on the examination mat with the right hand grabbing his penis and the left hand supporting his trunk.

Figure 2.

The X-ray film was taken on the admission day, showing a scoliotic left lumbar segment with a left convexity and right rotation and left pelvis anteriorly rotated. The arrow indicates the most convex spot of the vertebrae at the L4 level.

Examination

The patient entered the examination room with assistance in a forward-bent position requiring maximal assist to sit on the examination table. During the interview, he reported no unwanted or noticeable weight loss or gain in the last 12 months. When asked to lie down, the patient could only lie on his right side in the fetal position, which moderated his pain (4–5/10) (Figure 1). In the fetal position, palpation of lymph nodes in neck, submandibular area, axillary fossa, and along the inguinal canal area were conducted and no remarkable lumps identified. When not in the fetal position, complaints of severe burning pain at the penile root and anterior and superior scrotum, left greater than right, were voiced (pain 9/10). He denied any referred and/or radicular symptoms (including tingling and numbness) elsewhere or feeling of swelling in the scrotum. Inspection of the scrotum revealed no measurable edema. Lumbar spine palpation in right side-lying revealed a sharp, tender spot on the left L4 transverse process area.

The patient denied pain in the paravertebral muscles, pubic symphysis, bilateral flank/gluteal regions, including piriformis muscle and sacrotuberous ligament, and no swelling was identified in the lower extremities. The patient then rolled into the supine position with his left hip flexed where palpation revealed a taut, tender area near the left inguinal ligament mid-point. Manual muscle testing and lumbar range of motion were not measured due to complaints of pain. In addition, no lumps were identified along the inguinal canal, neck and in axillary fossa areas. After the examination, the patient’s daily living activities were assessed with the Barthel Index [11], and he received a score of 50.

Diagnosis

The patient reported pain at the root of the penis and the superior portion of the scrotum. Based on the location of pain, this could be caused by pathology of the following structures and their relation to the penile area: pubic symphysis, the origin of the adductor muscles, inguinal and femoral canals, spermatic cord, and femoral vessels and nerve, obturator nerve, dorsal nerve of penis (a branch of the pudendal nerve), iliohypogastric nerve, ilioinguinal nerve, genitofemoral nerve or upper lumbar region, in particular the L1 nerve root. Based on the patient’s present chief complaint, past medical history, current laboratory and radiological results, and physical examination, the following possible causes could be excluded (see Table 1 for the flowchart of differential diagnosis): adductor muscle strain, urinary stone, lower extremity infection, canal herniation, spermatic-related operation like vasectomy, and femoral or obturator nerve impingement. Based on the above and in consideration of the three main symptoms (a tender point at the left side of L4’s transverse process, pain at the root of the penis and superior portion of the left scrotum, and a cramping tender with palpation at the left lower abdominal area near the inguinal canal), we concluded that this patient’s problem might be related to involvement of a nerve or nerves innervating the penis and scrotum.

Table 1.

Flowchart – differential diagnosis of penile pain based on current symptoms and signs

Condition		Ruled out by
Herniation, vascular and lymphatic ; urinary disease, genital disease, cancer, bones, muscles, nerves	→	Blood test, equal strength and rate of pulses of bilateral femoral and dorsalis pedis, no history of LE inflammation and infection, no lump at the inguinal area and pain not associated with coughing or positioning changes – implies no herniation, vascular and enlarged lymph nodes.
Urinary disease, genital disease, cancer, bones, muscles, nerves	→	Urine test, US and Radiograph: negative. No urgency, frequency, or pain during urination- implies no: urinary diseases
Genital disease, cancer, bones, muscles, nerves	→	No genital abnormality identified, normal bilateral cremasteric reflexes – implies no genital diseases.
Bones, muscles, cancer, nerves	→	Radiograph and US: negative. Muscles attaching the pubic and proximal femur: no signs and symptoms of strain – implies no bone and muscles
Cancer, nerves	→	Acute onset, no unwanted weight loss or gain in last 12 months, no lumps identified along the inguinal canal, axillary fossa, and neck and submandibular area; no night sweating – implies no cancer
Nerves	→	No urinary retention without willingness to urinate; no tingling and numbness at perineal and anal areas – implies no caudal equina syndrome
Resulting condition:
Nerves	→	Dorsal branch pudendal n., genitofemoral n., ilioinguinal n., and ilio-hypogastric n.

LE, lower extremity; US, ultrasound; n, nerve.

Anatomically, three peripheral nerves (pudendal, genitofemoral, and ilioinguinal) supply innervation to the penis and scrotum, but each of these nerves innervates different areas of penis and scrotum (Table 2) [6–8]. The pudendal nerve from S2-4 exits the greater sciatic foramen between the piriformis and coccygeus muscles ventral to the sacrotuberous ligament to enter the lesser sciatic foramen where it splits into three branches: dorsal penile, perineal, and inferior rectal nerve. The pudendal nerve innervates the penile shaft, posterior scrotum, perineum, lower rectum, anus, and pelvic muscles [6,12–15]. The most common spots for potential pudendal nerve impingement are underneath the piriformis’ inferior border, between the deep sacrospinous and superficial sacrotuberous ligaments, or in the pudendal canal [6,14]. In this patient, palpation over the inferior piriformis, on the sacrotuberous ligament, and along the inferomedial edge of the inferior pubic ramus did not induce pain or reveal tender points. Further, no symptoms were noted in the sensory distribution for the shaft of the penis, perineum, or inferior rectum. Therefore, the pudendal nerve impingement could be excluded as a primary diagnosis.

Table 2.

Nerve innervation to the scrotum and penis

	Sensory to scrotum	Sensory to penis	Cremasteric reflex
Dorsal branch of pudendal nerve.	Posterior	Shaft	NA
Genital branch of genitofemoral nerve	Lateral	NA	Yes
Ilioinguinal nerve	Anteriorand superior	Root	NA
Ilio-hypogastric nerve	NA	NA	NA

Second, the genitofemoral nerve (GFN) of L1-2 pierces the psoas major muscle to travel inferiorly with genital and femoral branches along the anterior surface of the muscle [7,12,15,16]. The genital branch enters the internal inguinal ring to the inguinal canal and exits the external inguinal ring to innervate the cremasteric muscle and lateral scrotum. Morphologically, psoas major muscle tightness may cause impingement of the GFN, but this patient showed a normal cremasteric reflex bilaterally and no sensory deficit around the lateral scrotum, which possibly excludes the GFN impingement.

The third is the ilioinguinal nerve [8,12,15–17]. The L1 spinal root travels inferolateral underneath the psoas major muscle and splits to be superiorly the iliohypogastric nerve and inferiorly the ilioinguinal nerve, which continues in the inferolateral direction over the anterior surface of the quadratus lumborum and transverse abdominis [8,16,17]. The ilioinguinal nerve innervates penile root and anterior scrotum [8,16,17]. On its pathway to the genital area, this ilioinguinal nerve pierces the transverse abdominis (TA) near the vertical line through the anterior iliac crest and anterior superior iliac spine to travel between the internal oblique (IO) muscle and the TA. After traveling a short distance, this nerve pierces through the IO muscle at the mid-point spot just over the inguinal canal to enter the canal along the canal’s posterior wall and exits out the canal through the external inguinal ring to innervate the root of the penis and anterior and superior scrotum (Figure 3) [8,17]. So, based on the innervated area matching the area where the patient demonstrated pain, it is very likely an inguinal nerve impingement.

Figure 3.

Left anterior abdominal wall. (a). A vertical incision was made through the left anterior axillary line (red dash line) that resulted in available visualization of 3 layers of anterolateral abdominal wall muscles (from inside out): transverse abdominis (TA), internal oblique (IO), and external oblique (EO) on either side of the incision line. The common trunk from L1 is seen to split into ilio-hypogastric and ilioinguinal nerves between TA and IO. (b). ilioinguinal nerve can be found piercing through the IO 2–3 fingers above the inguinal ligament (the black dash line) to travel between IO and EO and further piercing EO to enter the inguinal canal. (C) After reflecting the anterior wall anteriorly and medially and internal organs removed, the nerves on the posterior abdominal wall can be observed, including the common trunk from L1 piercing the TA to enter the space between TA and IO. (Photos: Howe Liu).

The next was to check where this ilioinguinal nerve could be impinged and if the physical examination could support such an impingement. During the physical examination, a taut, tender structure was found above the middle inguinal canal, along with the reported pain location in penis and scrotum; this might indicate a compression area of the ilioinguinal nerve piercing the internal oblique muscle. Furthermore, radiographs demonstrate a scoliotic left lumbar segment with a left convexity and right rotation. This vertebral position could increase possible compression of nerves passing between the psoas major muscle and L2-4 transverse processes when the trunk rotates to the right side with an ipsilateral stiff psoas major muscle. This theoretically might explain why this patient needed maximal assistance with active trunk movement as the movement could contribute to the impingement and worsen the nerve-related symptoms. Therefore, based on findings above, a compression of the ilioinguinal nerve was thought to be the source of his pain.

In this case, the primary impingement spot of the ilioinguinal nerve is very likely where the nerve pierces the IO muscle. In the foraminal space between the psoas major and lumbar transverse processes might be a secondary spot, since the space is for both ilioinguinal and ilio-hypogastric nerves to pass [8,17]. The ilio-hypogastric nerve has no innervation for the penis and scrotum [8,12,15,17], hence eliminating ilio-hypogastric involvement in this case. Thus, the scoliotic lumbar area, plus with increased tightness of psoas major, might just increase the tension of ilioinguinal nerve at the lumbar area in certain situations like trunk right rotation.

Intervention

The initial intervention was to reduce tension in the lumbar area included treating the left L4 transverse process using a ligamentous articular strain technique [18] due to tenderness and being the peak of the scoliotic convexity to promote analgesia. The technique was applied with the patient in the right lateral recumbent position. The clinician (YL) applied pressure in an anterior, slightly superior, and medial direction with the thumb to the left L4 transverse process within patient tolerance. The clinician held the pressure until a softening of the tissue was felt and tenderness decreased, upon which the clinician gradually released the force. This was repeated three times by the clinician. This technique was followed by a HVLA manipulation to the mid-lumbar segments in the right lateral recumbent position by identifying the appropriate segments and completing a rotational thrust for segmental mobilization for neurophysiologic analgesia and to improve motion [19]. Next, the patient was assisted to the hook-lying position, and the clinician identified the taut, tender area just above the midpoint of the left inguinal canal. The clinician then applied a strain and counterstrain (SCS) technique, followed by soft tissue mobilization using a kneading technique until the tissue softened. This technique was also repeated three times by the clinician [20,21] (Figure 4). The SCS technique was the primary intervention for releasing the tension of the taut and tender structure, while the kneading one was to generally soften the surrounding area. The patient was reassessed following multimodal interventions aimed at decreasing tissue tone, and the patient’s numeric pain rating was decreased to 3–4/10. He was then able to slowly get off the treatment table and slowly walk out of the treatment room with contact-guard assistance. This treatment sequence was repeated for three additional days based on successful progress and reexamination of findings.

Figure 4.

(a) Strain and counterstrain (SCS) involves a passive shortening of the affected tissues containing the painful point into a position of ease and supporting the patient in the position-of-comfort for 90 s, then slowly returning the patient to a neutral resting position. The position-of-comfort should relieve both tenderness and fascial tightness. In this case, the technique was applied on the lower left abdomen near the inguinal canal. (b). Tuina kneading technique is a form of Chinese manipulative therapy that involves pressure moving in a circular pattern on an affected area with the thumb, the thenar eminence or the palm to relieve tension.

Outcomes

The patient’s symptoms resolved completely after 4 days of treatment. During reevaluation, an updated X-ray was taken and still showed the lumbar scoliosis, but the tender area on the left L4 transverse process and left inguinal region had resolved, and, more importantly, pain and discomfort in the penis and scrotum resolved with no more effect on bowel movement and urinary activity. Functionally, he was able to get on/off the treatment table independently, and he was discharged to home on the fifth day with a home exercise program (HEP). The HEP included slow deep breathing, stretching and strengthening in a position of lunge with trunk rotation, core stabilization, 12-form Tai Chi exercise, and body mechanics education on how to use tools in farmer’s field. On the discharge day, range of motion wise was assessed. He was able to maintain a standing position with knees straight when bending over with the middle finger to reach below the ipsilateral patella; bending back to touch on the ipsilateral gluteal fold, side-bending to touch on the proximal knee joint line on both left and right sides; and trunk rotation to make the trans-shoulder plane angled with the trans-ASIS plane in 30°–45° on the right turn and 45°–60° on the left turning . No pain was triggered when manual resistance was provided to these trunk movements above. He completed the Barthel Index for patient’s daily living activities, and he received a score of 95. Six months after discharge, he completed a phone interview and stated he had no further symptoms following physical therapy treatment and returned to full duty work on the farm.

Discussion

A noninvasive, manipulative intervention for ‘idiopathic’ penile pain has been rarely reported. The critical premise for treating this patient was to find the cause of the pain, potential neural entrapment site(s) and describe the manual therapy techniques based on the patient’s clinical manifestations, medical history, occupation, physical examination, laboratory, and radiological results.

The patient’s primary complaint was pain at the root of the penis and superior portion of the scrotum – indicating a possible ilioinguinal nerve impingement.

Anatomically the ilioinguinal nerve could be impinged in three areas [8,17]: the space between the psoas major muscle and the lumbar spine transverse processes; as the ilioinguinal nerve pierces the transverse abdominis muscle over the anterior superior iliac spine and iliac crest to travel between the TA and internal oblique muscles; and/or as the ilioinguinal nerve pierces the internal oblique muscle just superior to the mid-point of the inguinal ligament as it enters the inguinal canal. In this case, physical examination revealed (1) a taut, tender area above the left inguinal region and (2) a tender spot over the left L4 transverse process. These indicate that the ilioinguinal nerve was likely impinged between the psoas major and L4 transverse process or where it pierces through the internal oblique muscle. It is plausible that side bending and rotation of the lumbar vertebra toward the right side could narrow the space between the left psoas major muscle and the left L4 transverse process. The taut tender spot could be a local internal oblique muscular tightening reaction. These mechanical actions of local musculoskeletal structures could compress the passing ilioinguinal nerve and iliohypogastric nerve.

A movement abnormality and/or ligamentous tissue restriction could put direct tensile pressure to the nerve root at the location of the neural foramen (e.g. consideration of intraforaminal ligaments). In this case, the ligamentous articular strain [18] and HVLA [19] interventions were applied respectively to release the myofascial tissue tension in the lumbar area and to potentially enlarge the space between the psoas major and lumbar transverse processes; and consequently, decrease the possible compression on the ilioinguinal nerve and iliohypogastric nerve. The HVLA and ligamentous articular strain interventions did not change the scoliotic lumbar structure, but likely affected other soft tissue structures around the neural foramen, including psoas major and quadratus lumborum muscles, fascia, and the intervertebral disc.

The strain and counterstrain technique [20] and soft tissue kneading technique [21] were used to reduce abdominal muscle tension and relax the tension around the points where the ilioinguinal nerve and iliohypogastric nerve pierce through the transverse abdominis and internal oblique muscle near the left inguinal canal, where the tender area was palpated (Figure 3). Simultaneously, the soft tissue techniques may have altered tone and neuromuscular structures in the involved area. Although the ilioinguinal nerve is more likely involved based on the symptoms, we cannot completely rule out other structures involved, including the TA and internal oblique muscles.

Conclusion

This case illustrates how a thorough history, detailed examination, and a reasoned diagnostic process to evaluate anatomical structures may be contributing to unusual symptoms of penile pain. Physical therapists and other clinicians may require a detailed knowledge of relevant nerve pathways. The process in this case illustrates appropriate treatment and intervention strategies that can be applied by practicing manual physical therapists and clinicians to improve patient care when patients present with unusual but anatomical-based complaints. However, control trials are necessary to infer causation.

Biographies

Dr. Yingzhi Li is the Chair and Associate professor in the Department of Acupuncture and Manual Therapy in the Second Affiliated Hospital of the Yunnan University of Chinese Medicine. He received his degrees of Bachelor of Medicine and Masters and Ph.D. in Chinese Medicine from China. Dr. Li worked at the University of North Texas Health Science Center as a visiting scholar in 2018. Dr. Li is passionate about manual therapy and wellness, and about the use of osteopathic principles combined with Chinese Medicine for primary care.

Dr. Hao (Howe) Liu received his degrees of Bachelor of Medicine and Masters in Neuroanatomy from China, and degrees of Master of Physical Therapy and Ph.D. in Human Anatomy from the University of Mississippi Medical Center. He has been a licensed physical therapist engaging in teaching, research, and clinical practice in physical therapy (PT) in US for over 20 years. Currently, he is a full professor in the PT department at the University of North Texas Health Science Center. His research areas mainly focus on 1) how complementary and integrative therapy interventions like Tai Chi alone or in combination with traditional therapeutic exercise and/or hands-on manipulative techniques may work on patients, particularly the elderly ones; 2) how inappropriate use of assistive ambulatory devices (AADs) may affect on gait, balance, and posture in older adults under different conditions; and 3) surface projections of peripheral nerve pathways and potential impingement spots assessed in cadaveric labs.

Charles Nichols, PT, DPT, Sc.D. is an Assistant Professor for the Department of Physical Therapy for the University of North Texas Health Science Center. Dr. Nichols graduated from Texas Tech University Health Sciences Center with a Bachelor of Science degree in Physical Therapy. He then received his Doctor of Science degree in Physical Therapy from Texas Tech University Health Sciences Center in 2019. He is board-certified in orthopedics through the American Board of Physical Therapy Specialties, and a Certified Orthopedic Manual Therapist (COMT). He maintains his clinical practice at Therapy Excellence Inc.

Dr. Mason is the Assistant Dean of Osteopathic Clinical Education at the Texas College of Osteopathic Medicine, University of North Texas Health Science Center in Fort Worth, Texas. He is a professor in the Department of Family Medicine and Osteopathic Manipulative Medicine. He is board-certified in both Neuromusculoskeletal Medicine/Osteopathic Manipulative Medicine and Family Medicine. Dr. Mason is passionate about wellness and prevention and the use of osteopathic principles and practice integrated into primary care. He has been a board member on national committees of the American Academy of Colleges of Osteopathic Medicine, Chairing the Educational Council of Osteopathic Principles, the American Osteopathic Family Physicians, and The American Academy of Osteopathy as a board member. He serves as a board member for the Texas Medical Foundation Health Quality Institute and the American College of Graduate Medical Education Osteopathic Neuromusculoskeletal Medicine Residency Review Committee. Dr. Mason regularly lectures nationally and internationally on Manipulative Medicine and co-authored the “5-Minute Osteopathic Manipulative Medicine Consult” now in its second edition.

Funding Statement

The author(s) reported there is no funding associated with the work featured in this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).