Effects of upper and lower limb static exertions on global synkineses in hemiparetic subjects.
OBJECTIVE
Global synkineses are nonpurposive pathological involuntary muscle activities or movements elicited at several or all of the joints of the affected limb or limbs during voluntary forceful resisted contractions. The purpose of this study was to assess the effect of upper and lower limb exertions on manifestations of upper limb global synkineses in hemiparetic subjects.


METHODS
Involuntary muscle activities on the affected upper limb of 11 hemiparetic subjects and on the left or right upper limb of 10 control subjects were recorded using surface electromyography during successive bilateral maximal ankle exertions and during contralateral grips.


RESULTS
Significant differences in the level of involuntary electromyography (EMG) activities were observed between experimental conditions (ANOVAs, p < 0.05). EMG levels in hemiparetic subjects were significantly higher during contralateral grip tasks than during the ankle exertions.


CONCLUSIONS
These results suggest that upper limb global synkinases are more prevalent in specific tasks and that this task specificity may reflect the neurophysiological mechanisms involved in the generation of global synkinases.
Boissy
P
P
Neuromuscular Research Center, University of Boston, MA 02215, USA. boissyp@securenet.net
Bourbonnais
D
D
Gravel
D
D
Arsenault
A B
AB
Lepage
Y
Y
D000328:Adult; D000842:Ankle; D001132:Arm / Q000503:physiopathology*; D016022:Case-Control Studies; D004576:Electromyography; D005260:Female; D018737:Hand Strength; D006429:Hemiplegia / Q000628:therapy*; D006801:Humans; D007537:Isometric Contraction; D007866:Leg / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009122:Muscle Hypertonia / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D018482:Muscle, Skeletal / Q000503:physiopathology