Effect of sex and age on lower extremity sagittal plane asymmetry during single and double leg drop jump landings

The leg-dominance theory suggests that kinetic and kinematic asymmetries place athletes, particularly females, at a higher risk of non-contact anterior cruciate ligament (ACL) injuries. Sex and age effects on asymmetry of sagittal plane lower extremity joint angles and moments during the stance phase of double-leg (DJ) and single-leg (SJ) drop jump landings were examined between pre- and post-pubescent male and female athletes in this study. For the SJ, pre-pubescent athletes had significantly greater ankle and hip peak flexion angle asymmetries compared to post-pubescent athletes and an interaction effect was found for knee flexion angle, with pre-pubescent males having greater asymmetries. For the DJ, males had significantly greater peak hip extension moments compared to females. This study did not provide support to the leg-dominance theory with respect to explaining the higher prevalence of female ACL injuries.