Ensemble averaged electromyographic (EMG) signals for the four muscles recorded (100% speed shown). No significant differences in the mean root-mean-square (RMS) activity were observed between limbs within any of the four phases (loading, propulsion, initial swing, and terminal swing). Abbreviations: RF, rectus femoris; VL, vastus lateralis; MH, medial hamstrings; BF, biceps femoris