Hip strength in females with and without patellofemoral pain

Study Design: Cross-sectional. Objectives: To determine if females with anterior knee pain are more likely to demonstrate hip abduction or external rotation weakness than a similar, asymptomatic, age-matched control group. Background: Diminished hip strength has been implicated as being contributory to lower-extremity malalignment and patellofemoral pain. The identification of reliable and consistent patterns of weakness in this population may assist health care professionals establish a more effective treatment plan. Methods and Measures: Hip abduction and external rotation isometric strength measurements were recorded for the injured side of 15 female subjects with patellofemoral joint pain (mean SD age, 15.7 +/- 2.7 years; age range, 12-21 years). These were compared with strength measurements from the corresponding hip of 15 age-matched female control subjects (mean +/- SD age, 15.7 +/- 2.7 years; age range, 12-21 years). All strength measurements were made using hand-held dynamometers. Results: Subjects with patellofemoral pain demonstrated 26% less hip abduction strength (P<.001) and 36% less hip external rotation strength (P<.001) than similar age-matched controls. Conclusions: The results indicate that young women with patellofemoral pain are more likely to demonstrate weakness in hip abduction as well as external rotation than age-matched women who are not symptomatic.