RESEARCH REPORT PLATFORM PRESENTATION

EFFECTS OF TASK-SPECIFIC LOCOMOTOR AND STRENGTH TRAINING IN AMBULATORY STROKE SURVIVORS. Sullivan K¹, Brown D², Klassen T¹, Mulroy S³, Ge T¹, Azen S¹, Winstein C¹; ¹University of Southern California, Los Angeles, California, USA. ²Northwestern University, Chicago, Illinois, USA. ³Rancho Los Amigos National Rehabilitation Center, Downey, California, USA

PURPOSE: A phase II, multi-site, single-blinded, randomized clinical trial (RCT) was conducted to determine the independent and combined effects of task-specific and LE strength training on walking outcomes post-stroke. RELEVANCE: Impaired walking ability is a hallmark residual deficit that contributes to post-stroke walking disability. Impairment in lower extremity muscle strength is a significant contributor to decreased walking speed after stroke. No studies have combined task-specific locomotor training in combination with lower extremity strength training programs designed to improve post-stroke walking outcomes. PARTICIPANTS: Participants included 80 individuals (mean age 61±12.4 years) who were ambulatory, but walked slower than 1.0 m/sec and were at least 6 months post unilateral stroke (stroke onset 25±16.2 months). METHODS: Participants were stratified by initial comfortable walking speed (moderate>0.5 m/sec; severe ≤0.5 m/sec) and randomized to one of four exercise pairs: 1) body-weight supported treadmill training (BWST) and locomotor-based strength training (resistive cycling task, LBST), 2) BWST and LE muscle-specific strength training (MSST), 3) BWST and upper extremity ergometry (SHAM), and 4) LBST and SHAM.Training occurred 4 times per week for 6 weeks (24 total sessions). Exercise type in each exercise pair was alternated daily. Primary outcomes were comfortable and fast overground walking speed, and distance walked in 6-minutes measured at baseline, after 12 and 24 treatment sessions and at a 6-month follow-up. ANALYSIS: Interactions between severity, treatment group, and time were assessed by using a repeated measures ANOVA model for each of the primary outcome measures. RESULTS: The BWST/SHAM group had significantly greater increases in walking speed compared to the LBST/SHAM group (pre-post change in comfortable velocity = 0.12 +/− 0.14 m/sec vs. 0.01 +/− 0.07 m/sec, p = .004), change in fast velocity = 0.09 +/− 0.14 m/sec vs. 0.01 +/− 0.09 m/sec, p = .03), but improvement in 6 min walk distance was comparable between the two groups. All BWST groups made similar significant improvements in walking speed and distance with training (p < 0.0001) that were evident regardless of whether LE strength training (LBST, MSST) was combined or not (SHAM). Walking improvements for the BWST groups were maintained at the 6-month follow-up. CONCLUSIONS: After stroke, task-specific training using body-weight support during treadmill walking is more effective in improving walking speed than resisted cycling. Furthermore, a moderate intensity LE progressive resistive training program alternated daily with task-specific treadmill walking did not provide an added benefit to walking outcomes. IMPLICATIONS: The findings provide strong evidence for the effectiveness of intense, task-specific training to improve walking outcomes after stroke. Further work is necessary to determine how exercise programs that combine muscle strengthening protocols with task-specific training can be implemented to maximize function and voluntary muscle torque capability in individuals post-stroke. KEYWORDS: Clinical Trials, Exercise, Walking Recovery. FUNDING ACKNOWLEDGEMENTS: This study was supported by a grant from the Foundation for Physical Therapy to establish the Physical Therapy Research Network (PTClinResNet): a clinical research network to evaluate the efficacy of physical therapist practice.

ETHICS COMMITTEE: University of Southern California Institutional Review Board