Sex differences in total frontal plane knee movement and velocity during a functional single-leg landing

ObjectivesFemales land with more knee valgus than males. While most studies have evaluated lower extremity mechanics during double leg landing, most sports require single-leg landing from a double or single leg takeoff. Further, knee movement occurs toward both varus and valgus during functional landing. The purpose of this study was to determine if differences exist between females and males in total frontal plane movement and velocity of the knee during single-leg landing.DesignExperimental cohort.SettingMotion analysis laboratory.ParticipantsForty healthy, physically-active females (n = 20) and males (n = 20).Main outcome measuresThree-dimensional motion analysis was completed on the lower extremities during double-leg jumping followed by a single-leg landing. Student's t-tests (p ≤ 0.05) were used to determine if differences exist in frontal plane knee angles (valgus and varus excursion) and angular velocities between females and males.ResultsFemales demonstrated greater knee valgus and varus excursion, and valgus and varus velocities compared to males (p < 0.05).ConclusionsThese findings suggest that total movement in the frontal plane at the knee may be an important factor in injury mechanics in females. Further, single-leg landing from a functional jump should be considered when comparing landing biomechanics between females and males.