How do strength, sensation, XXXX and joint individuation relate to the reaching deficits of people with chronic hemiparesis?

@entity73 @entity508 @entity71 @entity26906 @entity425 @entity51 @entity2720 @entity717
Hemiparetic subjects present with @entity717 including @entity425 , @entity508 and an inability to isolate movement to one or a few joints. Voluntary attempts to move a single joint often result in excessive motion at adjacent joints. We investigated whether the inability to individuate joint movements is associated with @entity71 . Controls and hemiparetic subjects performed two different @entity717 and three individuated arm movements, all in the parasagittal plane. The @entity717 were a sagittal 'reach up' ( @entity26906 ) and 'reach out' (shoulder flexion and elbow extension). Joint individuation was assessed by getting each subject to perform an isolated flexion-extension movement at each of the shoulder, elbow and wrist joints. In addition, we measured strength, muscle tone and sensation using standard clinical instruments. Hemiparetic subjects showed varying degrees of impairment when performing @entity717 and individuated joint movements. @entity73 (hand path curvature, velocity) were worse in the reach out versus the reach up condition. Typical joint individuation abnormalities were @entity2720 that should have been held fixed during movement of the instructed joint. Hemiparetic subjects tended to produce concurrent flexion motions of shoulder and @entity2720 when attempting any movement, one explanation for why they were better at the 'reach up' than the 'reach out' task. Hierarchical regression analysis showed that impaired joint individuation explained most of the variance in the reach path curvature and end point error; strength explained most of the variance in reaching velocity. Sensation also contributed significantly, but @entity508 and strength were not significant in the model. We conclude that the @entity51 reflects a fundamental motor control problem that largely explains some aspects of @entity51 of hemiparetic subjects.
