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Wed, Sept 28

Speaker: Neha Lodha, Ph.D.

Title: Influence of Task Constraints on Bimanual Force Control Post Stroke

Abstract: Stroke survivors exhibit different degrees of unilateral motor disability in both upper limbs. Thus, the execution of everyday bimanual tasks that require collaboration between hands is severely compromised following stroke. Substantial empirical evidence suggests the presence of greater strength deficits in the paretic hand relative to the non-paretic hand.  Does this finding imply that the paretic hand will contribute less force as compared to the non-paretic hand in all bimanual tasks? Are alternative force control strategies possible?

This study determined the influence of task constraints on ability to produce and coordinate forces in bimanual tasks, post stroke. Task constraints were manipulated by two specific bimanual isometric contractions: (a) wrist/finger extension and (b) power grip. Participants matched target, submaximal force levels displayed on a monitor while receiving visual feedback of the combined force produced by both hands together. The results show that the paretic hand contributes less force as compared to the non-paretic hand in a bimanual wrist/finger extension; however, this relationship was reversed in bimanual power grip. More importantly, regardless of the nature of the task, reduction in stroke severity was associated with increased symmetry and coordination in bimanual tasks.  An important implication involves rehabilitation protocols that emphasize training both hands to produce symmetric forces that are temporally coordinated.
Host: Dr. Mirbagheri