Combined Functional Task Practice and Dynamic High Intensity Resistance Training Promotes Recovery of Upper-extremity Motor Function in Post-stroke Hemiparesis

Abstract

Weakness is a significant impairment in persons with post-stroke hemiparesis, yet traditional clinical perspectives caution against strengthening in neurological populations. Significant correlations between weakness and functional movement have been demonstrated, however, a clear relationship between increased strength and functional improvement has been elusive. This case study describes a combined program of dynamic, high-intensity resistance training and functional task practice for the upper-extremity in adult hemiparesis. The patient was a 65-year-old, right hand dominant woman who presented to the Neural Control of Movement Laboratory at the Palo Alto VA Rehabilitation Research and Development Center 16 weeks following clipping of an unruptured aneurysm with consequent dense right hemiparesis. She received 7 weeks of acute rehabilitation according to CARF guidelines (ie, at least 3 hours of two or more disciplines, 6 days per week). Her baseline research evaluation revealed significant upperextremity deficits at the ICF body structure/function level including: weakness, shoulder pain, mild resistance to passive movement, and need for moderate to maximal assistance in many activities of daily living including bathing and dressing. The Stroke Impact Scale score reporting her perspective indicated she had recovered from her stroke only 50%. The hybrid resistance training-functional task practice intervention, detailed in this report, was delivered 3 times per week for 6 weeks with each session lasting 75:00. The subject revealed marked improvements in isometric and dynamic force production in 5 key upper-extremity actions: elbow flexion, elbow extension, shoulder flexion, shoulder abduction, and shoulder external rotation. Strength gains were accompanied by increased EMG activation immediately postintervention and by a combination of increased activation and apparent hypertrophic effects at 6 month follow up. Marked improvements were noted in all clinical and functional measures and in an elbow trajectorytracking task which served as a surrogate measure of motor control. Improvements in strength and positive outcome effects at the physiological, clinical, and functional levels were observed in this subject following the experimental hybrid upper-extremity rehabilitation intervention described. Importantly, no deleterious effects were observed including exacerbation of spasticity or musculoskeletal compromise. Observations of improved EMG activation in this case study suggest that improvements in motor activation underlie these strength gains and can likely be attributed to working at a high intensity level.