Comparison of 3D, Assist-as-Needed Robotic Arm/Hand Movement Training Provided with Pneu-WREX to Conventional Table Top Therapy Following Chronic Stroke

Objective—Robot-assisted movement training can help individuals with stroke reduce arm and hand impairment, but robot therapy is typically only about as effective as conventional therapy. Refining the way that robots assist during training may make them more effective than conventional therapy. Here we measured the therapeutic effect of a robot that required individuals with a stroke to achieve virtual tasks in three dimensions against gravity. Design—The robot continuously estimated how much assistance patients needed to perform the tasks and provided slightly less assistance than needed in order to reduce patient slacking. Individuals with a chronic stroke (n = 26, baseline upper extremity Fugl-Meyer score = 23 ± 8) were randomized into two groups and underwent 24 one hour training sessions over 2 months. One group received the assist-as-needed robot training and the other received conventional table top therapy with the supervision of a physical therapist. Results—Training helped both groups significantly reduce their motor impairment, as measured by the primary outcome measure, the Fugl-Meyer score, but the improvement was small (3.0 ± 4.9 points for robot therapy, versus 0.9 ± 1.7 for conventional therapy). There was a trend for greater reduction for the robot trained group (p = 0.07). The robot group largely sustained this gain at the three-month follow-up. The robot-trained group also experienced significant improvements in Box and Blocks score and hand grip strength, while the control group did not, but these improvements Correspondence: David J. Reinkensmeyer, PhD, Department of Mechanical and Aerospace Engineering, Department of Anatomy and Neurobiology, Department of Biomedical Engineering, University of California at Irvine, 4200 Engineering Gateway, Irvine, CA 92697-3975. Disclosures: Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article. This report summarizes work supported by NCRR M01RR00827 and under Federal Contract N01-HD-3-3352 by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and co-funded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB). The findings and conclusions in the report are those of the authors and do necessarily represent the views of NICHD, NIBIB, or NCRR. David Reinkensmeyer has a financial interest in Hocoma, A.G., a company that makes robotic therapy devices. The terms of this arrangement have been reviewed and approved by the University of California, Irvine, in accordance with its conflict of interest policies. NIH Public Access Author Manuscript Am J Phys Med Rehabil. Author manuscript; available in PMC 2013 November 01. Published in final edited form as: Am J Phys Med Rehabil. 2012 November ; 91(11 0 3): S232–S241. doi:10.1097/PHM. 0b013e31826bce79. N IH PA Athor M anscript N IH PA Athor M anscript N IH PA Athor M anscript were not sustained at follow-up. In addition, the robot-trained group showed a trend toward greater improvement in sensory function, as measured by the Nottingham Sensory Test (p = 0.06). Conclusions—These results suggest that, in patients with chronic stroke and moderate-severe deficits, assisting in three dimensional virtual tasks with an assist-as-needed controller may make robotic training more effective than conventional table top training.