Comparison of lower extremity EMG between the 2-leg squat and modified single-leg squat in female athletes.

PURPOSE To compare EMG activity of selected hip and knee muscle groups in female athletes performing a modified single-leg squat and the 2-leg squat using the same relative intensity. METHODS Eleven Division I female athletes from a variety of sports (soccer, softball, and track) completed the study. EMG measurements were taken as the subjects completed 3 parallel repetitions at 85% of their 3-repetition maximum on each exercise. Mean and mean peak EMG data from the gluteus medius, hamstrings, and quadriceps and the quadriceps:hamstrings EMG ratio were compared between the 2 exercises. RESULTS Statistically higher mean (P < .01) and mean peak (P < .05) gluteus medius and mean and mean peak (P < .01) hamstring EMG activity occurred during the modified single-leg squat. The 2-leg squat produced higher mean and mean peak (P < .05) quadriceps activity and a higher quadriceps:hamstrings EMG ratio (P < .01). CONCLUSION Muscle-recruitment patterns appear to differ between the 2 types of squat exercises when performed at the same relative intensity by female athletes.