Variation in motor evoked responses of lower limb muscles during different postural tasks

Militskova Alena Dmitrievna, Mukhametova Elvira Rishatovna, Baltina Tatyana Valeryevna

A comparative electromyography study of the lower extremity muscles was undertaken in order to compare responses under three experimental conditions: standing with eyes-open on hard and foam surface and with eyes-closed on hard surface. It was shown that transcutaneous electrical spinal cord stimulation at the level Th11-Th12 with pulse-duration 1ms and 0.1Hz frequency induce monosynaptic refectory responses in the hip and crural muscles while postural tasks performance in healthy subjects. Evoked responses amplitude analysis showed that both elimination of visual control and alteration of supporting surface (standing on foam surface) significantly decrease the amplitude of transcutaneous electrical spinal cord stimulation evoked responses in crural muscles.

Keywords:transcutaneous electrical stimulation of the spinal cord, postsynaptic inhibition, evoked responses, spinal cord, postural control