F. Baldissera et al., Changes in the excitability of the H-reflex in wrist flexors related to the prone or supine position of the forearm in man, NEUROSCI L, 295(3), 2000, pp. 105-108
The effect of the forearm position, prone vs. supine, on the excitability o
f the H-reflex in flexor carpi radialis (FCR) muscle was tested in nine adu
lt volunteers by comparing the recruitment profiles of the H and M waves. T
he H-reflex size, normalized to the maximal M response, was lower when the
forearm was supine than when it was prone, with an average reduction of abo
ut 50% over most of the H-recruitment curve. In three wrist positions, inte
rmediate between prone and supine, the amount of reflex attenuation was rel
ated to the prone-supination angle. Control experiments excluded that the c
hanges in the H reflex excitability were due to displacements of the sti mu
rating or recording electrodes. (C) 2000 Elsevier Science Ireland Ltd. All
rights reserved.