Sex-Differences in the Relative Distribution of Lower Extremity Sagittal Plane Moments During Landing

Abstract

Sex-differences in movement strategies may contribute to increased anterior cruciate ligament (ACL) injury risk in female athletes. This may be due to quadriceps dominance in females that is characterized by lower quadriceps-hamstrings strength and activation ratios compared to males. However, sex-differences in hip and ankle function may also be related to knee injury risk, considering their ability to stabilize the knee during high-risk athletic tasks. Sex-differences in the relative distribution of sagittal plane moments through the hip, knee, and ankle are not well understood. PURPOSE: To determine if male and female collegiate basketball players employ different landing strategies in the relative distribution of sagittal plane moments at the hip, knee, and ankle. METHODS: Twenty-three Division 1 male (N=11) and female (N=12) basketball players participated in the study. Established 3D motion analysis techniques were utilized to collect three trials of a drop vertical jump. The percent distributions of each lower extremity joint (hip, knee, ankle) relative to the summated sagittal plane moment during the landing phase of the DVJ were calculated. Sex-differences in normalized external sagittal plane moments (Nm/kg) and relative percent distributions were examined using ANOVA (p<0.05). RESULTS: There were significant sex-differences in hip flexion (M: 2.93Nm/kg, F: 1.68Nm/kg, p<0.001), but not knee flexion (p=0.34) or ankle dorsiflexion (p=0.12) external moments when normalized to bodyweight. Male athletes appeared to employ a more hip-dominant strategy, with a higher distribution of sagittal plane moments at the hip (41.1%), compared to the knee (31.6%). Female athletes preferentially utilized a knee strategy, characterized by a higher relative distribution of sagittal plane moments at the knee (37.1%, p=0.007) and lower distribution at the hip (33.6%, p=0.009) compared to male athletes. There were no significant sex-differences in the relative distribution of sagittal plane moments at the ankle (M: 27.4%, F: 29.4%, p=0.29). CONCLUSION: In the sagittal plane, male basketball players preferentially utilize a hip-dominant landing strategy, whereas female basketball players utilize a knee-dominant landing strategy. These differences may help explain the sex disparity in ACL injury rates.