TABLE 2.

Nine Studies Identified for Inclusion in Systematic Review

Author	Purpose	Methodology and Participants	Measures	Injury Incidence and Prevalence	Identified Risk Factors	PEDro Score	Limitations	Strengths
Bennett et al12	Evaluate foot type as predictor of medial tibial stress syndrome	High school runners, single season n = 125	Navicular drop, gastroc length, rearfoot angle, tibiofibular varum	15/125 runners (12% total; 2/57 or 4% men, 13/68 or 19%) or women had MTSS symptoms. Incidence not reported.	Sex and navicular drop associated with MTSS (r2 = 0.18 navicular drop; r2 = 0.24 sex, P < 0.05). OR not reported	5	Assessment of MTSS did not explicitly rule out stress fracture with bone scan/radiograph, navicular drop was measured postinjury	Easily obtainable measure, highly specific clinical definition of MTSS
Cain et al13	Evaluate foot pronation/supination as risk factor for foot/ankle overuse injury	High school-aged male indoor soccer players, single season n = 76	Foot Posture Index, coach-rated ability	32% of players sustained at least 1 ankle/foot injury during the season. Incidence not reported	Supination and under pronation (FPI score less than 2) associated with foot/ankle overuse injury (sensitivity 89% specificity 50%)	8	Male participants only, foot posture index scoring system requiring significant training of novice evaluators (two 2-h sessions)	Playing h factored into analysis, injury defined by self-report of pain resulting in missed h
Finnoff et al14	Evaluate hip strength as a risk factor PFPS in high school runners	High school runners, age 14–18 yrs, single season (n = 98)	Weight, leg lengths, isometric hip strength (external rotation, internal rotation, abduction, adduction, flexion, extension)	5/98 subjects experiences PFPS symptoms. 2/53 or 3.7% men, 3/44 or 6.8% women. Incidence not reported	Lower hip ER:IR strength ratio increased risk of PFPS (P = 0.08); higher ER:IR ratio was protective (OR < 0.01; CI < 0.01–0.44; P = −0.02). Higher abd strength (OR, 5.4; CI, 1.5–29.5; P < 0.01) and abd: add ratio (OR, 14.14; CI, 0.90–220; P = 0.05) increased risk	5	Low recruitment rates, reenrollment of 4/98 subjects across multiple seasons, unable to report reliability data for strength testing	Easily testable in clinic setting, also reported effect of agonist-antagonist strength imbalance in addition to individual muscle groups
McHugh et al16	Evaluate balance and hip strength as predictors of ankle injury	High school-aged male and female football, basketball, gymnastics, and American football players, 2 seasons, (n = 169)	Hip flexion, abduction, adduction, strength through hand-held dynamometer, single-limb balance on tilt board, body mass index, ligamentous laxity	27 lateral ankle sprains recorded. Incidence 1.47/1000 exposures. Prevalence of injured athletes not reported	Higher body mass index in male athletes and history of previous ankle strain were significant predictors of injury; balance and strength were not (P > 0.05)	8	Injury prevalence not reported in detail. Nonstandard report of incidence. Did not discriminate between game or practice time	Large sample size, 2-yr follow-up, men and women included in model, previous injury included in model, power analysis conducted, training h considered in model
Myer et al17	Evaluate joint laxity as ACL injury risk factor in female athletes	Female high school-aged soccer and basketball players, 4 seasons, (n = 95 nested case–control from total n = 1558)	Generalized joint laxity tests, AP tibiofemoral translation (CompuKT knee arthrometer) in bilateral knees	19/1558 subjects sustained ACL tears (1.2%). Incidence not reported	Side to side differences in knee laxity associated with increased ACL injury risk (OR, 4.0 per 1.3 mm difference; CI, 1.7–9.7). Positive knee hyperextension increased injury risk (OR, 5.0; CI, 1.2–18.4)	8	Model restricted to ACL injury only, requires specialized equipment, training h not included in model	Nested case–control design with internally validated prediction model, large sample size, broad population of interest
Plisky et al18	Evaluate balance as a risk factor for lower extremity injury in basketball players	Male and female high school basketball players, single season (n = 235)	SEBT	54/235 (23%) of athletes sustain a LE injury. Incidence not reported	R/L reach distance disparity >4 cm increased injury risk OR, 2.7; CI, 1.4–5.3 all, 3.0 (1.1–7.7 men). Normalized composite reach distance less than 94% increased LE injury risk (OR, 3.0; CI, 1.5–6.1 all; OR, 6.5; CI, 2.4–17.5 women)	7	19% dropout rate, multiple trials required for accurate SEBT assessment, training h not included in model	Previous injury accounted for in model, large sample size, men and women
Turbeville et al19	Evaluate risk factors for injury in high school American football players	High school-aged male American football players (13–19 yrs), 2 seasons (n = 717)	Report of preseason conditioning, body mass index, grip strength, playing experience	132 injuries reported among 100/717 (13.9%) players over 2 seasons. 62% were LE injuries; 38% were UE injuries. Incidence not reported	Physical characteristic were not associated with injury risk. Players with previous injuries or more playing experience (OR, 1.34) at increased LE injury risk	6	Study-designed for overall injury risk, injury rates underreported relative to historical data, individual training h not included in model	Easily obtainable measures, data applicable to specific positions played, preseason conditioning and use of special equipment (eg, brace) recorded
Wang et al20	Evaluate ankle injury risk factors in high school basketball players	High school male and female basketball players, single season, (n = 42)	Isokinetic ankle strength (Cybex 6000, Biodex dynamometer), ankle ROM, ankle endurance, postural sway (forceplate)	18/42 (43%) players sustained ankle injuries; incidence not reported	Postural sway was only variable associated with injury (OR, 1.2; CI, 1.09–1.36; P < 0.01)	6	25% dropout rate, specialized equipment required, small sample size	Training h included in model, strict inclusion criteria with control for shoe type, bracing, training surface