Rectus femoris: Its role in normal gait

Objective: To analyze the role of the rectus femoris muscle in nondisabled gait at various walking velocities using fine-wire dynamic electromyography. Design: Descriptive study. Fine-wire electromyography data were collected from the rectus femoris during level walking at four walking speeds. Rectus femoris activity patterns in the loading response phase and the pre- and initial-swing phase of the gait cycle were compared using paired t tests. Setting: A gait laboratory. Subjects: Ten nondisabled adult volunteers. Main Outcome Measures: Amplitude of rectus femoris activity in the loading response phase and the pre- and initial-swing phase during walking at four speeds. Results: There was a bimodal pattern of rectus femoris activity in all subjects, at all speeds, in both phases, with high variability in the onsets, durations, and amplitudes of activity, and paired t tests revealed no significant differences (p > .05) between phases at any walking speed. Conclusion: Activity in the rectus femoris in the pre- and initial-swing phase in nondisabled individuals at all speeds suggests that similar activity detected in individuals with stiff-legged gait may not be inappropriate.