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.