Comparison of footwear and barefoot kinetics and kinematics during various sporting movements

BACKGROUND: The ability of athletic shoes in enhancing athletic performance is attributed to the elastic energy storage and recovery in its cushioning system, however much remains unclear about the efficacy of wearing athletic shoes and the influence of the athletic shoes on knee joint biomechanics. The aim of this study was to investigate the effects of wearing athletic shoes on the kinematics and kinetics of the knee joint during four different athletic movements, including walking, running, jumping and sidestepping. The hypothesis was that the effect of athletic shoes on knee biomechanics would differ depending on the type of movements. METHODS: Knee joint kinematics and kinetics in walking, running, jumping and sidestepping were assessed in both barefoot and shod conditions. Nineteen healthy recreational athletes participated in this study. Three dimensional joint force, joint angle, and joint moment were calculated using a three dimensional motion analysis system. The variables evaluated in this study included the time of stance phase, velocity of the movement, ground reaction force, peak joint angles, and peak joint moments in the sagittal, frontal, and transverse planes. The biomechanical variables were compared between barefoot and shod conditions using a paired t-test. RESULTS: The amplitude of the velocity and the ground reaction force were significantly greater in shod walking, running, and sidestepping. The knee flexion angle was significantly greater in shod walking, running, and jumping, while the knee flexion moment was significantly greater in shod walking and running. The abduction angle, abduction moment, and external rotation moment were significantly greater in shod sidestepping. CONCLUSIONS: Athletic footwear changes the kinematics and kinetics in the knee j oint during walking, running, j umping, and sidestepping, and the effects of the athletic footwear on knee joint motion vary depend on the types of athletic movements. A deeper understanding of how humans adapt to altered properties of the foot ground interface during different movement tasks may enhance our knowledge of the mechanisms of load regulation in human motion.