Knee Forces During Landing in Men and Women

Sex differences in biomechanics may provide one explanation for the greater incidence of knee injuries in women, but few studies have compared internal forces. In this study, a musculoskeletal model was used to compare male and female, bilateral and unilateral landings based on motion capture and force plate data. Participants were classified as landing medially or laterally loaded based upon the mediolateral load share at the knee (bilateral: p < 0.001, η(2)=0.452; unilateral: p < 0.001, η(2) = 0.444). Knee kinematics and ground reaction forces were not different between the two groups (p > 0.05, η(2) = 0.001 – 0.059), but there were differences in muscular recruitment. Landing strategy did not appear to be dependent on sex. However, for both medially and laterally loaded bilateral landings men had greater gluteal (p = 0.017, η(2) = 0.085) and hamstrings forces (p < 0.001, η(2) = 0.183), whereas women had greater quadriceps forces (p = 0.004, η(2) = 0.116). This study demonstrates an association between muscular recruitment and medially loaded landings. Landing strategy seems to be a function of skill not sex; however, within a particular landing strategy there may be sex differences in muscular activation that contribute to the difference in injury rates.