Somatosensory evoked potentials modification related to isometric voluntary contraction.

Somatosensory evoked potentials were elicited by applying an electrical stimulus to the median nerve while the subjects performed a handgrip isometric contraction. Somatosensory evoked potentials (SEPs) were recorded from scalp positions C3 + 2 and C3-2. SEPs during the increase phase and decrease phase of force, and during the hold phase (period of maintenance of steady force) of isometric contraction were compared with potentials during rest.