Task context and reaching performance after stroke: Effects of target distance and trunk restarint

Task context and reaching performance after stroke: Effects of target distance
Abstract
Purposes: To examine the effect of target distance on reaching performance in persons after stroke and the influence of voluntary trunk movement on the arm endpoint trajectory during reaching.
Methods: Twenty-five persons after stroke using ipsilesional arm performed reaching task. Kinematics of reaching movements to targets placed within arm length, arm length and beyond arm length were analyzed.
Results: As reaching distance increased, the velocity, displacement and active joint ranges of trunk and arm increased. Whenever the trunk was involved, there was a stereotyped sequential recruitment of the arm and trunk in that the trunk began moving before the hand. The trunk played an important role in positioning the hand close to the target during the terminal stage of the reaching movement.
Conclusions: Reaching distance affected the spatio-temporal aspects of coordination between the trunk and arm. The trunk not only acts as a postural stabilizer during reaching, but also becomes an integral component in positioning the hand close to the target. Persons with left brain damage showed deficits in trunk and arm movement trajectory control and in temporal coordination of trunk and arm.


Task context and reaching performance after stroke:
Effects of target distance and trunk restraint
Abstract
Purpose: To examine the effects of context on reaching performance in persons with stroke.
Methods: Twenty-five persons with stroke used ipsilesional arm to perform an upper-extremity reaching task under four experimental conditions, formed by the crossing of target distance and trunk restraint.
Results: Significant and large effects of target distance and trunk restraint were found on increasing elbow and shoulder joint ranges. Movement smoothness was improved under condition of trunk restraint and target placed in near distance.
Conclusions: The results of this study showed that the influence of internal and external constraints on reaching performance. Participants with left brain damage and apraxia showed deficits in movement trajectory control. The ability of trunk control affected reaching performance in the variables of movement time and reaction time.