Effect of rehabilitation tasks on organization of movement after stroke

The purpose of this study was to examine the effect of presence or absence of an object (goal-directed action vs. rote exercise) and the effect of functional specificity of the object on the organization of reaching movements of persons who have had a stroke.

A repeated-measure counterbalanced design was used in each of two experiments. Eighteen persons who had been hospitalized after stroke were recruited from the roster of a rehabilitation hospital and through stroke clubs and volunteered to participate. Fourteen of these became the data-producing sample. In Experiment 1, the OPTO-TRAK/3020 motion analysis system was used to record movement when the participants reached for preferred food (goal-directed action) or to a spatial location (rote exercise). In Experiment 2, the system recorded movement when participants reached to pick up the receiver of an active telephone (natural context), a detached receiver (partial context), and a stick (simulated context). The organization of the reach movement was described kinematically as the number of zero crossings of the acceleration profile (smoothness), movement time (speed), displacement, peak velocity (an indication of force), and location of peak velocity in the velocity profile (planning strategy).

Goal-directed action produced significantly smoother, faster, more forceful, and more preplanned movement than did the rote exercise condition. Functional specificity of the context did not significantly affect organization of the reach.

Goal-directed reach enabled persons with stroke to display characteristics typical of reach to a target by persons who have not had a stroke better than reaching out in space. These findings support the occupational therapy practice of using objects in a functional context to improve coordinated movement. However, the nature of the objects to be used requires further study.