Lower Extremity Strength Differences in Male and Female NCAA Collegiate Soccer Athletes

Abstract

Non-contact ACL tears are a common occurrence in collegiate soccer. However, the incidence of injury is significantly higher in females than males. The mechanisms accounting for this disparity are unclear. It has been postulated that there may be a link between non-contact ACL tears and lower extremity strength. PURPOSE: The purpose of this study was to examine the hip and knee strength in collegiate soccer athletes. METHODS: 60 male (19.70 ± 1.22 years, 179 ± 7.22 cm, 76.05 ± 8.14 kg) and 60 female (19.43 ± 1.18 years, 167 ± 6.03 cm, 62.94 ± 6.73 kg) Division I Collegiate Soccer Athletes were evaluated. Subjects performed 3 trials of a 5 s max isometric contraction with a 10 s rest period between each trial. The motions assessed were hip abduction (AB), hip adduction (AD), hip internal rotation (IR), hip external rotation (ER), hip flexion (HF), hip extension (HE), knee extension (KE), and knee flexion (KF).Data were collected using a portable fixed dynamometer (Evaluator, BTE Technologies, Hanover, MD). Force in newtons (N) was normalized to percentage of body weight (force [N]/mass [kg] ˙9.81), reported as %Bwt. Torque was also calculated and normalized [(torque [Nm]/weight [N] x height [m]) × 100], reported as %T. Data were analyzed using two 2 (gender) × 8 (motion) multivariate ANOVAs. RESULTS: There was a significant difference (p<.05) in normalized strength for all motion except hip IR [males, 20.72 ± 5.26 (%Bwt) and females, 19.09 ± 5.25 (%Bwt)] and KF [males, 35.65 ± 8.77 (%Bwt) and females, 33.46 ± 7.81 (%Bwt)]. Finally, there was a significant difference (p<.05) for all motions in regards to normalized torque. CONCLUSION: The present study shows males are significantly stronger than females with the exception of normalized hip IR and KF. The inability of the female limb to create torque values similar to males may play a critical role in ACL susceptibility. Supported by NIH 1R03 AR054031-01