Neuromuscular Changes Contributing to Hand Weakness after Stroke - Rehabilitation Institute of Chicago

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Fri, Nov 12

Speaker: Megan Conrad

Title: Neuromuscular Changes Contributing to Hand Weakness after Stroke

Abstract: The ability to generate hand forces is fundamental for grasping, transporting and manipulating objects.  After a stroke, weakness is prevalent in the arm and hand (Ada et al, 2003; Boissy et al, 1999) and is a primary factor contributing to impairment (Kamper et al, 2006).  An understanding of the mechanisms underlying weakness is a necessary first step in the development of appropriate therapies.  We have measured that changes in passive tissue impedance and muscle atrophy are limited.  Thus, we believe that changes in motor unit properties and their activation may be largely responsible for the observed weakness.  Additionally, in preliminary experiments we have observed changes in the frequency content of electromyographic (EMG) signals in hemiparetic muscle during maximum voluntary contractions (MVCs).  The shift in frequency content may directly result from underlying changes in the neuromuscular properties of the muscle.This presentation will outline our previous findings regarding hand weakness after stroke.  Additionally, it will outline our future plans to assess motoneuronal factors contributing to changes in EMG data following stroke with the understanding that these factors are likely contributors to hand weakness.