[Immediate and remote postactivation effects in the human motor system].

Postactivation effects (appearance of long-lasting non-voluntary contraction of muscles after 30-60 s of the sustained voluntary effort) were studied. It is shown that after contraction of distal muscles postactivation effects can appear in proximal muscles not involved in the previous voluntary activity. The testing of the motor system state by the muscle tendon vibration revealed that besides the well known immediate postactivation effects there were concealed changes lasting for 15-20 min. It is suggested that postactivation phenomena reflecting the functioning of certain central tonogenic structures activated by a voluntary effort or by an increased afferent inflow can be used as an efficient tool in the study of postural mechanisms.