Lower limb strength, flexibility, and running biomechanics in adolescents with and without Osgood-Schlatter disease: comparisons by sex.

OBJECTIVES: To compare lower limb strength, flexibility, and running biomechanics in adolescents with and without Osgood-Schlatter disease according to sex. DESIGN: Retrospective chart review. SETTING: Hospital-affiliated outpatient sports medicine clinic. PARTICIPANTS: 100 adolescents with and without Osgood-Schlatter disease (n = 25 each group). MAIN OUTCOME MEASURES: Mass-normalized sagittal and frontal hip strength and sagittal knee strength, and quadriceps femoris and hip flexor flexibility were assessed. Limb crossover, contralateral pelvic drop, medial knee displacement, and tibial dominant stride were evaluated during treadmill running. RESULTS: Compared with sex-matched healthy peers, female adolescents with Osgood-Schlatter disease had lower hip abduction strength and greater hip flexion strength, and a higher odds of contralateral pelvic drop and medial knee displacement (d = -1.70-0.71; odds ratio = 4.00-4.85; 0.001≤P ≤ 0.03), whereas male adolescents with Osgood-Schlatter disease had greater hip and knee sagittal plane strength yet less flexibility (d = -1.60-1.00; odds ratio = 3.71; 0.001≤P ≤ 0.02). Compared with male adolescents with Osgood-Schlatter disease, female adolescents with Osgood-Schlatter disease had lower hip and knee strength, greater quadriceps femoris flexibility, and higher odds of frontal plane biomechanical deviations (d = -1.41-1.38; odds ratio = 4.03-4.54; 0.001≤P ≤ 0.02). CONCLUSIONS: We identified differences in lower limb muscular and biomechanical features among adolescents with Osgood-Schlatter disease according to sex that may inform tailored rehabilitation strategies for this population.