Combined Task-Specific Training and Strengthening Effects On Locomotor Recovery Post-Stroke

Abstract

Task-specific and strength training have demonstrated efficacy as therapeutic interventions poststroke. The intent of this case study is to describe outcomes associated with a therapy program that combines task-specific and strength training in an individual post-stroke and to discuss some possible mechanisms and modulating factors that may affect post-stroke neurologic recovery and responsiveness to intervention. The participant was a 38-year-old female with right middle cerebral artery stroke, evaluated 15 months postonset. She ambulated independently with an ankle-foot orthosis and straight cane. Her free and fast overground velocity was 0.50 m/s and 0.62 m/s, respectively. Body-weight supported treadmill training and a limb-loaded cycling exercise were alternated over 24 treatments sessions (4 times/wk for 6 wks). Measurements were taken pre-, post-treatment, and at a 6-mo follow-up. Instrumented gait and motion analysis with fine-wire EMG recording of LE muscle activity occurred pre- and post-treatment. Post-treatment, walking speed increased 18% for free--(0.59 m/ s) and 14.4% for fast-velocity (0.71 m/s); 6-min walking distance increased 4% (184.4 m). At 6-mos, continued improvements in all walking outcomes were evident. Gait and motion analysis revealed that functional locomotor recovery was associated with increases in magnitude of paretic leg gluteus maximus and gluteus medius activation during gait. Motion analysis confirmed an increase of hip and knee extension motions throughout stance and swing. For the person in this case clinically meaningful changes in walking function were associated with a combined therapeutic program that included both task-specific and LE strength training. Possible mechanisms associated with response to therapy were related to improved motor unit activation associated with increased strength in key muscles used in gait.