The objective of this Phase II clinical trial is to identify how exercise training parameters, particularly the specificity and intensity of stepping practice, influence long-term mobility outcomes in patients with subacute stroke. Previous work indicates these variables can influence the efficacy of training interventions in individuals without neurological injury, with some data to support their utility in chronic stroke. However, studies that systematically assess the independent and combined effects of these principles in individuals early following stroke are sparse. This critical research gap impedes clinical translation, and current clinical practices remain adherent to traditional theories of rehabilitation, including lower intensity interventions focused on underlying impairments. Additional concerns of providing only high-intensity walking training revolve around the lack of attention toward movement quality will result in use of compensatory movement strategies that could be reinforced with repeated practice, or that other risks of cardiovascular events should preclude high-intensity training. Unfortunately, there is little data to support these hypotheses, and our studies suggest that application of these training parameters can strongly influence walking function, as well as improve underlying impairments and improve gait kinematics. Our approach is to characterize the effects of these training variables on recovery of locomotor function and quality, as well as changes in impairments and other mobility tasks in patients early post-stroke, in an effort to evaluate whether such training influences neurological recovery or whether patients utilize compensatory strategies. In this 2x2 factorial RCT design, Aim 1 of the study will characterize changes in mobility function associated with manipulation of specific and intensity of exercise interventions. We will evaluate functional measures of gait speed and endurance, spatiotemporal symmetry, as well as measures of cardiopulmonary fitness. We postulate that combined application of high-intensity, task specific stepping practice will result in significantly greater increases in locomotor measures as compared to lower intensity or non-specific training paradigms. In Aim 2, we will characterize the changes in impairments (strength) and other mobility tasks (balance, sit-to-stand transfers) to determine whether stepping intervention can mitigate the major impairments underlying post-stroke impairments. Quantitative measures of volitional strength will be the primary outcomes. In Aim 3, we will characterize changes in community mobility and quality of life, the later of which can inform us about cost-effectiveness. Overall, these results have potential implications on the delivery of effective exercise interventions in person with subacute stroke.
The proposed research will evaluate the individual and combined effects of task-specificity and intensity of rehabilitation interventions on locomotor function, community mobility and quality of life in patients with subacute (1-6 months) post-stroke.