HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 543/1/307    most recent 2002.023986v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Stinear, J. W. Articles by Byblow, W. D. Search for Related Content PubMed PubMed Citation Articles by Stinear, J. W. Articles by Byblow, W. D.

Disinhibition in the human motor cortex is enhanced by synchronous upper limb movements

James W. Stinear and Winston D. Byblow

The phasic modulation of wrist flexor corticomotor disinhibition has previously been demonstrated during the flexion phase of rhythmical passive flexion-extension of the human wrist. Here we ask if rhythmical bimanual flexion-extension movements of the wrists of neurologically intact subjects, modulate inhibitory activity in the motor cortex. In the first experiment intracortical inhibition was assessed when one wrist was passively flexed and extended on its own, with the addition of the opposite limb voluntarily moving synchronously in a mirror symmetric pattern, and also in a near-symmetric asynchronous pattern. Two subsequent experiments investigated firstly the modulation of spinal reflex pathway activity during the same three movement conditions, and secondly the effect of contralateral wrist movement alone on the excitability of corticomotoneuronal pathways to a static test limb. When the wrist flexors of both upper limbs were shortening simultaneously (i.e. synchronously), intracortical inhibition associated with flexor representations was suppressed to a greater extent than when the two muscles were shortening asynchronously. The results of the three experiments indicate that modulation of inhibitory activity was taking place at the cortical level. These findings may have further application in the study of rehabilitation procedures where the effects of simultaneous activation of affected and unaffected upper limbs in hemiparetic patients are to be investigated.

This article has been cited by other articles:

				C. M. Stinear, P. A. Barber, J. P. Coxon, M. K. Fleming, and W. D. Byblow Priming the motor system enhances the effects of upper limb therapy in chronic stroke Brain, May 1, 2008; 131(5): 1381 - 1390. [Abstract] [Full Text] [PDF]

				W. D. Byblow, J. P. Coxon, C. M. Stinear, M. K. Fleming, G. Williams, J. F. M. Muller, and U. Ziemann Functional Connectivity Between Secondary and Primary Motor Areas Underlying Hand-Foot Coordination J Neurophysiol, July 1, 2007; 98(1): 414 - 422. [Abstract] [Full Text] [PDF]

				R. G. Carson, C. J. Smethurst, Y. Oytam, and A. de Rugy Postural Context Alters the Stability of Bimanual Coordination by Modulating the Crossed Excitability of Corticospinal Pathways J Neurophysiol, March 1, 2007; 97(3): 2016 - 2023. [Abstract] [Full Text] [PDF]

				R. G Carson, S Riek, D. C Mackey, D. P Meichenbaum, K Willms, M Forner, and W. D Byblow Excitability changes in human forearm corticospinal projections and spinal reflex pathways during rhythmic voluntary movement of the opposite limb J. Physiol., November 1, 2004; 560(3): 929 - 940. [Abstract] [Full Text] [PDF]