Alterations of evoked electromyographic responses by passive stretch or shortening of the skeletal muscle
Abstract
Skeletal muscles are controlled by action of central nervous system end final level of control is provided by spinal motoneurons. The motoneuron pool in spinal cord is supplied by inputs from periphery, same and other levels of the central nervous system.
The final adjustment of excitability of the motoneurons might thus highly influence control of the muscle movements. Hofman reflex (H reflex) is electrophysiological parallel to monosynaptic stretch reflex, which can is evoked by electrical stimulation of the nerve.
By precise evaluation of a recruitment curve of H reflex and M wave we can evaluate excitability of the motoneuron pool during various situations. Present study was designed to elucidate an effect of passive stretch and shortening of the muscle on motoneuron excitability.