Principal Investigator: Carolynn Patten, PhD, PT Project Staff: Peter S. Lum, PhD, Kevin C. McGill, PhD; Heather E. Brown, MSPT; Dhara Kothari, MS PT; Sara M. Northrop, MPT; and Ruth Yap, MS Project Category: Stroke - 2004 Objective: The underlying premise of this study is that upper-extremity rehabilitation for persons with post-stroke hemiparesis can be significantly improved by increasing the intensity of rehabilitation activities. We conducted a controlled, randomized, double-blind clinical trial to study the effects of shoulder and elbow strength training in subjects in the subacute and chronic phases of recovery following stroke. In the subacute arm of the study (operationally defined at 2-6 months post-CVA) we compared the experimental intervention of standard functional rehabilitation combined with elbow and shoulder strength training against a control intervention of standard functional rehabilitation alone. In the chronic arm of the study (operationally defined as 6-18 months post-CVA) all subjects received both standard and experimental therapies in a cross-over design. Research Plan and Methods: We hypothesized that subjects who receive resistance training in addition to standard functional rehabilitation would demonstrate greater gains in elbow and shoulder strength and greater improvements in functional performance than the control group without experiencing increased hypertonia. We studied the neuromuscular mechanisms underlying these improvements in strength and control of movement. Clinical Relevance to the VA: At present, there is little definitive Level I evidence that rehabilitation for stroke is effective. The current state of research suggests that therapies involving more treatment, and especially more intense treatment, may be more effective for restoring motor function in the upper-extremity. This study directly tests two forms of therapy with the goal of identifying the more effective, efficient and persistent approach to restoring upper-extremity motor function. This research holds the potential to produce evidence regarding the effectiveness of therapeutic interventions for post-stroke rehabilitation. Our future plans are to continue this line of research, refining the therapeutic interventions based on our findings, to increase the sample population, and to identify physiological mechanisms responsible for recovery of motor function. Progress Reports and Findings to Date: We have found that the experimental treatment involving both task practice and high-intensity resistance training produces superior effects to standard treatment (task practice alone) across levels of impairment, function and disability. These effects are retained, and extended following six months without additional treatment. In addition, remarkable improvements in spasticity were demonstrated following the experimental treatment while no such systematic effects were demonstrated following task practice. Finally, biomechanical power, or the time-dependent aspect of force production was remarkably improved following the experimental treatment. We believe that improved power underlies improved functional performance. Research Plan for the Next Year: The funded aspect of this clinical trial ended on 31 December, 2003. We continue to analyze data and submit manuscripts. A proposal for continuation of this project has been submitted to VA RR&D Merit Review. We await results of the review process. Funding Source: VA Merit Review Funding Status: Completed |
