[Study of the silent period during the post-stimulus histogram method]

Isotonic contractions of human hand muscles were elicited by nerve stimulation and the silent period was studied on single motor units employing post-stimulus histograms. At submaximal M-response (up to 70% of M-maximum) the motoneurons under study were not stimulated and thus the after-hyperpolarization was excluded from the experiment. Under these conditions the latency of the silent period was not less than 60 ms and the silent period parameters were similar to those after subthreshold for M-response nerve stimulation and to those after skin stimulation. The experiments proved that neither recurrent inhibition nor spindle unloading affected the spinal centres of muscles under study.