Comparison of knee mechanics among risky athletic motions for noncontact anterior cruciate ligament injury

It has been suggested that noncontact anterior cruciate ligament injury commonly occurs during sports requiring acute deceleration or landing motion and that female athletes are more likely to sustain the injury than male athletes. The purpose of this study was to make task-to-task and male-female comparisons of knee kinematics and kinetics in several athletic activities. Three-dimensional knee kinematics and kinetics were investigated in 20 recreational athletes (10 males, 10 females) while performing hopping, cutting, turning, and sidestep and running (sharp deceleration associated with a change of direction). Knee kinematics and kinetics were compared among the four athletic tasks and between sexes. Subjects exhibited significantly lower peak flexion angle and higher peak extension moment in hopping compared with other activities (P < .05). In the frontal plane, peak abduction angle and peak adduction moment in cutting, turning, and sidestep and running were significantly greater compared with hopping (P < .05). No differences in knee kinematics and kinetics were apparent between male and female subjects. Recreational athletes exhibited different knee kinematics and kinetics in the four athletic motions, particularly in the sagittal and frontal planes. Male and female subjects demonstrated similar knee motions during the four athletic activities.