Short-term effects of practice with trunk restraint on reaching movements in patients with chronic stroke - A controlled trial

Background and Purpose - In prehension tasks with objects placed within arm's reach, patients with hemiparesis caused by stroke use excessive trunk movement to compensate for arm motor impairments. Compensatory trunk movements may improve motor function in the short term but may limit arm recovery in the long term. Previous studies showed that restriction of trunk movements during reach-to-grasp movements results in immediate increases in active arm joint ranges and improvement in interjoint coordination. To evaluate the potential of this technique as a therapeutic intervention, we compared the effects of short-term reach-to-grasp training (60-trial training session) with and without physical trunk restraint on arm movement patterns in patients with chronic hemiparesis. Methods - A total of 28 patients with hemiparesis were assigned to 2 groups: 1 group practiced reach-to-grasp movements during which compensatory movement of the trunk was prevented by a harness ( trunk restraint), and the second group practiced the same task while verbally instructed not to move the trunk ( control). Kinematics of reaching and grasping an object placed within arm's length were recorded before, immediately after, and 24 hours after training. Results - The trunk restraint group used more elbow extension, less anterior trunk displacement, and had better interjoint coordination than the control group after training, and range of motion was maintained 24 hours later in only the trunk restraint group. Conclusions - Restriction of compensatory trunk movements during practice may lead to greater improvements in reach-to-grasp movements in patients with chronic stroke than practice alone, and longer-term effects of this intervention should be evaluated.