EMG analysis of stereotyped voluntary movements in man.
EMG activity was recorded in biceps and triceps while subjects voluntarily flexed their elbows during a visual matching task. With fast flexion, the initial EMG was characterized by a triphasic pattern with a burst of activity first in biceps, then in triceps with a silent period in biceps, and finally in biceps again; these components were analysed quantitatively. Smooth flexion was characterized by continuous activity in biceps. Inhibition of tonic activity of triceps in relation to a fast flexion occurred in the 50 ms before the initiation of biceps activity. A patients with a severe pansensory neuropathy performed normally on these tasks. Physiological mechanisms underlying these patterns are analysed; an important conclusion is that the triphasic activity with fast flexion is 'centrally programmed'.
D000328:Adult; D004576:Electromyography; D005260:Female; D006801:Humans; D009043:Motor Activity / Q000502:physiology*; D009132:Muscles / Q000502:physiology*; D013239:Stereotyped Behavior / Q000502:physiology