[Recurrent inhibition of the flexor muscle motoneurons of the human forearm under the effect of vibration and static muscle strain].

By use of H-reflex technique reflex flexor muscles motoneurons recurrent inhibition was studied for man forearm muscle. It was observed the reduce of this inhibition with the muscles strain. The vibration, acting to the strained muscle, showed a disappearance of inhibition. It was marked that these features can be connected to both segmental or supraspinal action to motoneurons or Renshaw cells. The recurrent inhibition is reduced more effectively under complex vibration and muscle strain influence than under only strain factor, and it is connected to the vibration. It seems to be connected to the more activated receptors number. It is suggested that supraspinal inhibiting action on Renshaw cells is preferred in this mechanism. Possible role of the presynaptic inhibition is discussed that can be effective through skin or joint afferents of flexor reflex.