earticle

영어

The purpose of this study was to investigate the effects of various posture in squat exercises on muscle activations of vastus medialis oblique (VMO) and vastus lateralis (VL). There was to suggest the optimal training posture of squat exercise for healthy young women, athletics, or patellofemoral pain syndrome. Twenty-four healthy young adults participated spontaneously in this study, and had no medical history of anterior knee pain or any lower extremity disorders. Surface electromyography (EMG) was used to collect the data of muscle activation in VMO and VL. Surface EMG data were collected at each angle in dominant knee joint (15, 35, and 60 degrees) and foot positions (internal rotation, neutral, and external rotation). The normalized EMG activity levels (%MVIC) of the VMO and VL were compared using two-way ANOVA with repeated measures. There was significant main effects of knee joint angles and foot positions, and interaction effect on EMG activities of VMO and VL. VMO/VL ratios by different foot position. There was an interaction effect between knee joint angles and different foot position. A externally rotated foot position produced significantly more VMO/VL activity ratio than that from internally rotated position and neutral position, although there was not significantly different in the three angles in knee joint. These findings suggest that squat exercise at externally rotated position is the effective way. The results of this study are also to suggest the optimal training posture of squat exercise is externally rotated foot position for healthy young women, athletics, or patellofemoral pain syndrome.