Investigators: Charles G. Burgar, MD and H.F. Machiel Van der Loos, PhD Project Staff: Peter S. Lum, PhD; Peggy Shor, BS OTR; Matra Majmundar, OTR TYC; Douglas F. Schwandt, MS; and James H. Anderson, JEM Project Category: Stroke - 2000 The prevalence of stroke in DVA patients is increasing as aging veterans join the population at highest risk. Upper limb paralysis is often resistant to therapeutic efforts. More effective methods are needed to maintain or restore the dexterity necessary for daily activities. Therapists routinely incorporate passive and active-assisted movements into treatment of hemiparesis. Such therapy is time-consuming, costly, and often limited in duration by financial resources. This project studied the ability of a device (MIME) to assist limb movements and facilitate recovery of motor function in subjects with chronic hemiparesis due to stroke. MIME incorporates an industrial robot and operates in three unilateral modes and one bimanual mode. In unilateral operation, passive, active-assisted, and guided movements against a resistance are possible. The bimanual mode enables the subject to practice bilateral, coordinated movements with rate and range under his or her control. This was a prospective, blinded, controlled clinical trial. Thirty chronic stroke subjects were randomly assigned to a test group or control group. Both groups received 24 one-hour sessions over a 2 month period. The test group practiced reaching movements (tabletop and vertical) and planar tracing of circles and polygons, with the paretic limb assisted by the robot. The control group received conventional NDT-based therapy of the same intensity and duration. A therapist blinded to group assignment evaluated all subjects pre- and post-treatment with standard clinical scales. Findings to Date: Twenty-eight subjects (14 in each group) completed the study. All had improved motor function. The robot-assisted group showed a trend for greater overall improvement than the control group. Treatment-specific effects were observed (i.e., the shoulder/elbow portion of the Fugl-Meyer score increased in both groups, with gains in the robot group significantly higher than the control group (p < 0.05), while gains in wrist/hand scores were only minimal; consistent with the study protocol that emphasized shoulder and elbow movements). Analysis of biomechanical data suggests possible mechanisms for the improvements, including strength gains and improved motor control in paretic muscles, with increased agonist and decreased antagonist activity. Publications and Presentations: Lum PS, Burgar CG, Kenney D, Van der Loos HFM. Quantification of force abnormalities during passive and active-assisted upper-limb reaching movements in post-stroke hemiparesis. IEEE Transactions Biomedical Engineering 46(6):652-62, 1999. Lum PS, Van der Loos HFM, Shor P, Burgar CG. A robotic system for upper-limb exercises to promote recovery of motor function following stroke. Proceedings, 6th International Conference on Rehabilitation Robotics ICORR'99;1999 July 1-2, Stanford, CA. p. 235-9. Burgar CG, Lum PS, Shor M, Van der Loos HFM. Rehabilitation of upper limb dysfunction in chronic hemiplegia: Robot-assisted movements vs. conventional therapy. Arch Phys Med Rehabil 80(9):1121, 1999. Related Work Funding Source: VA RR&D Merit Review |
