This study evaluated the effect of context on the reaching performance of the unaffected arm and postural control while standing in patients with right cerebral vascular accidents (RCVA) and in healthy adults. Fifteen subjects with RCVA and sixteen healthy subjects performed tasks with the right hand under two conditions while standing. One condition involved moving coins forward on a table as far as possible (concrete task) and the other reaching forward without a target (abstract task). Forward reaching distance, forward displacement and lateral shift of center of pressure (CoP), and weight distribution were the dependent variables. The RCVA and control groups achieved significantly greater reaching distances in the concrete task than in the abstract one. The RCVA group showed significantly less lateral shift of the CoP and placed more weight on the affected leg in the concrete than the abstract task, whereas the control group made a greater lateral shift in the concrete task and had a similar mean ratio of weight distribution during both tasks. The results demonstrate that a functional application of task targets may favorably modulate both reaching and posture performance and exert various positive affects on postural control. Such applications may have a place in the therapeutic recovery efforts for patients afflicted with stroke.
Hsieh-ching Chen, Keh-chung Lin, Chia-ling Chen and Ching-yi Wu
Ching-yi Wu, Shih-han Chou, Mei-ying Kuo, Chiung-ling Chen, Tung-wu Lu and Yang-chieh Fu
Stroke patients are often left with hemiplegia or hemiparesis of the upper extremities, severely limiting the ability to perform bimanual and functional activities. No studies have investigated how stroke patients adapt their movements to changes in object size in functionally asymmetric bimanual tasks. The influence of object size on intralimb and interlimb coordination during an asymmetrical, functional bimanual task was examined in patients with left cerebral vascular accidents (LCVA) and healthy controls. Fourteen LCVA patients and 13 age-matched controls were instructed to reach to grasp a large and a small jar with the right/affected hand and to open the cap with the other hand. Movement kinematics was analyzed for intralimb coordination (spatial and temporal planning of reaching and grasping) and interlimb coordination (bimanual synchronization and temporal association of the hands). The results demonstrate a spatial adaptation of reaching in the affected hand to the object size and deficits in temporal planning of grasping with the affected hand to object size in the stroke patients. Movement adaptations of the unaffected hand in the stroke patients were similar to those in the healthy adults. Bimanual coordination was independent of object size for both groups.