TY - JOUR
T1 - Electromyographic analysis of joint-dependent global synkinesis in the upper limb of healthy adults
T2 - Laterality of intensity and symmetry of spatial representation
AU - Hwang, Ing Shiou
AU - Wang, Chun Hou
AU - Chen, Yi Ching
AU - Cho, Chiung Yu
AU - Yeung, Kwok Tak
N1 - Funding Information:
The authors are grateful to Miss Hsiu-Ching Chiu for her assistance in data collection. This research was in part supported by a grant from the National Science Council, Taiwan, under Grant no. NSC 91-2314-B006-141, and NSC 92-2314-B-040-005.
Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2006/8
Y1 - 2006/8
N2 - The intensity and spatial representation of electromyographical (EMG) activity were examined to characterize the effects of limb dominance and movement direction upon global synkinesis (GS). Twenty-two healthy young subjects (11 men, 11 women) with a mean age of 24.7 years participated in this study. Three trials of EMG activities from eight primary muscles in the unexercised limb were recorded when a maximal isometric contraction in various directions was performed by the shoulder, elbow, and wrist of the dominant and non-dominant upper limbs. The features of GS, including intensity and spatial representation, were quantified with standardized net excitation levels (SNE) and relative excitation (RE), respectively. Our data indicated that (1) GS intensity was strongly limb-dependent with a larger SNE level arising when target joints of the non-dominant upper limb were active, (2) the GS intensity was more influenced by movement direction of the non-dominant limb than by that of the dominant limb, (3) the gradient change in GS intensity was observed bilaterally with a larger SNE level associated with contralateral movements of a proximal joint than a distal joint, and (4) GS spatial representations of the upper limbs were patterned and symmetrical, but seemly insensitive to movement direction. Laterality in GS intensity and structured GS spatial representation with symmetry could be a consequence of use-dependent hemispheric organization.
AB - The intensity and spatial representation of electromyographical (EMG) activity were examined to characterize the effects of limb dominance and movement direction upon global synkinesis (GS). Twenty-two healthy young subjects (11 men, 11 women) with a mean age of 24.7 years participated in this study. Three trials of EMG activities from eight primary muscles in the unexercised limb were recorded when a maximal isometric contraction in various directions was performed by the shoulder, elbow, and wrist of the dominant and non-dominant upper limbs. The features of GS, including intensity and spatial representation, were quantified with standardized net excitation levels (SNE) and relative excitation (RE), respectively. Our data indicated that (1) GS intensity was strongly limb-dependent with a larger SNE level arising when target joints of the non-dominant upper limb were active, (2) the GS intensity was more influenced by movement direction of the non-dominant limb than by that of the dominant limb, (3) the gradient change in GS intensity was observed bilaterally with a larger SNE level associated with contralateral movements of a proximal joint than a distal joint, and (4) GS spatial representations of the upper limbs were patterned and symmetrical, but seemly insensitive to movement direction. Laterality in GS intensity and structured GS spatial representation with symmetry could be a consequence of use-dependent hemispheric organization.
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U2 - 10.1016/j.jelekin.2005.07.012
DO - 10.1016/j.jelekin.2005.07.012
M3 - Article
C2 - 16243541
AN - SCOPUS:33745197964
SN - 1050-6411
VL - 16
SP - 313
EP - 323
JO - Journal of Electromyography and Kinesiology
JF - Journal of Electromyography and Kinesiology
IS - 4
ER -