Effects of Strength Training on Upper-extremity Function in Post-stroke Hemiplegia

Principal Investigator: Carolynn Patten, PhD, PT

Project Staff: Peter S. Lum, PhD; KevinC. McGill, PhD; Heather E. Brown; Dhara Kothari; Sara M. Northrop; and Ruth Yap

Project Category: Stroke

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 are conducting 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. Our operational definition of subacute is completion of all outpatient therapy programs, but less than 6 months post-CVA. For purposes of this study, chronic describes subjects between 6 and 18 months post-CVA who have completed all outpatient therapies. In the subacute arm of the study we compare this 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 all subjects receive both standard and experimental therapies in a cross-over design.

We hypothesize that subjects who receive resistance training in addition to standard functional rehabilitation will demonstrate greater gains in elbow and shoulder strength and greater improvements in functional performance than the control group without experiencing increased hypertonia. We will study the neuromuscular mechanisms underlying these improvements in strength and control of movement resulting from these interventions.

Project Milestones to Date:

1. Experimental and therapeutic protocols have been established,

2. Reliability testing for the trajectory-tracking task has been completed with11 hemiparetic adults. These data have been analyzed and presented at the annual VA RR&D Meeting (Feb, 2002) and a manuscript is in revision for the Journal of Rehabilitation R&D,

3. Reliability testing for torque data has been completed with 10 hemiparetic adults. These data have been reduced and statistical analysis is currently being performed,

4. A cross-sectional MRI study demonstrating activation impairment in 8 hemiparetic adults has been completed. These data have been analyzed and were presented at the International Society for Magnetic Resonance in Medicine in May, 2002. A manuscript is in preparation,

5. A cross-sectional analysis of the torque development deficit is being conducted in data obtained from the baseline evaluation session. A manuscript will be submitted from this data analysis,

6. 12 subjects have been enrolled in the subacute arm of the study, 5 of these subjects have completed the six-month follow up study. All subjects demonstrated clinically and functionally significant improvements on the clinical battery of outcome measures. Due to blinding involved in the study design, specific details of the results will be withheld until the end of the study,

7. Thirteen subjects have been enrolled in the chronic arm of the study, seven of these subjects have completed the six month follow up evaluation,

8. Analysis of the biomechanical and kinematic data is proceeding for both the subacute and chronic arms of the study.

Dr. Peter S. Lum transferred to the Richmond, VA VAMC and remains involved in the project.

Funding Source: VA RR&D Merit Review

Funding Status: Funded