Biomechanical differences between unilateral and bilateral landings from a jump: Gender differences

Objective: To determine the effect of landing type (unilateral vs. bilateral) and gender on the biomechanics of drop landings in recreational athletes. Design: This study used a repeated measures design to compare bilateral and unilateral landings in male and female athletes. A repeated measures multivariate analysis of variance (type of landing*gender) was performed on select variables. Setting: Biomechanics laboratory. Participants: Sixteen female and 16 male recreational athletes. Main Outcome Measures: Kinetic, kinematic, and electromyographic (EMG) data were collected on participants while performing bilateral and unilateral landings from a 40-cm platform. Results: Compared to bilateral landings, subjects performed unilateral landings with increased knee valgus, decreased knee flexion at initial contact, decreased peak knee flexion, decreased relative hip adduction, and increased normalized EMG of the rectus femoris, medial hamstrings, lateral hamstrings, and medial gastrocnemius (P < 0.005). During both types of landing, females landed with increased knee valgus and normalized vertical ground reaction force (VGRF) compared to males (P < 0.009), however, the interaction of landing type*gender was not significant (P = 0.29). Conclusions: Compared to bilateral landings, male and female recreational athletes performed unilateral landings with significant differences in knee kinematic and EMG variables. Female athletes landed with increased knee valgus and N/GRF compared to males during both types of landing.