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The role of cutaneous sensation in the motor function of the hand
Author(s) -
Ebied Ayman M.,
Kemp Graham J.,
Frostick Simon P.
Publication year - 2004
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1016/j.orthres.2003.12.005
Subject(s) - sensation , isometric exercise , physical medicine and rehabilitation , wrist , handwriting , afferent , psychology , proprioception , sensory system , carpal tunnel syndrome , audiology , medicine , neuroscience , physical therapy , computer science , anatomy , surgery , artificial intelligence
We studied the effect of abolishing cutaneous sensation (by infiltrating local anaesthetic around the median nerve at the wrist) on the ability of 10 healthy volunteers (a) to maintain a submaximal isometric pinch‐grip force for 30 s without visual feedback, and (b) to perform a fine finger‐manipulation „handwriting” task. Blocking cutaneous sensation had no effect on ability to maintain pinch force, suggesting that muscle afferents have the major role in force‐control feedback. However, a near‐linear fall in force, present with or without block (mean slope = −1.3 ± 0.2% s −1 ), which cannot be attributed to motor fatigue, reveals a shortcoming of the afferent feedback system. Blocking cutaneous sensation did impair ability to perform the more demanding writing task, as judged by an 18 ± 6% increase in the length of the path between target points, a 22 ± 9% increase in the duration of the movement and a 63 ± 24% in „normalised averaged rectified jerk”, an averaged time‐derivative of acceleration (all significantly nonzero, P < 0.04). These experiments demonstrate the relative importance of muscular and cutaneous afferent feedback on two aspects of hand performance, and provide a way to quantify the deficit resulting from the lack of cutaneous sensation. © 2003 Published by Elsevier Ltd. on behalf of Orthopaedic Research Society. All rights reserved.