کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4065187 | 1266243 | 2010 | 7 صفحه PDF | دانلود رایگان |
The objective of this study was to investigate the reciprocal influences of stance pattern (bilateral stance vs. unilateral stance) and thumb-index precision grip task (static target vs. dynamic target) on postural–suprapostural tasks by manipulating task-load. Fifteen healthy volunteers participated in four postural–suprapostural tasks, including static force-matching in bilateral/unilateral stance (BS_static; US_static), dynamic force-matching in bilateral/unilateral stance (BS_dynamic; US_dynamic), and two control tasks in bilateral and unilateral stances without a finger task. The normalized force error (NFE), reaction time (RT) of the finger tasks, and normalized change in center of pressure sway (ΔNCoP) were measured. For suprapostural task performance, a significant interaction effect between postural and suprapostural tasks on NFE of the finger tasks was noted (static: BS < US; dynamic: BS > US), but RT was not different among the four tasks. For postural task performance, negative ΔNCoP during unilateral stance indicated a spontaneous reduction in postural sway due to added force-matching. In contrast, addition of force-matching tended to increase postural sway during bilateral stance, but postural fluctuations decreased as task-load of suprapostural task increased (BS_dynamic < BS_static). In conclusion, performance of postural–suprapostural tasks was differently modulated by task-load increment. Our observations favored adaptive resource-sharing and implicit expansion of resource capacity for a postural task with a motor suprapostural goal.
Journal: Journal of Electromyography and Kinesiology - Volume 20, Issue 3, June 2010, Pages 413–419