Prediction of walking recovery after stroke can inform patient-centered care and support discharge planning. The accuracy of current prediction models is limited, however, due in part to small study designs and narrow predictors assessed. We propose a comprehensive evaluation of a novel combination of biomarkers to improve prediction of walking recovery and guide rehabilitation efforts after stroke. These include acute structural brain network disruption (utilizing MRI); blood biomarker levels (e.g., brain-derived neurotrophic factor and vascular endothelial growth factor); and clinical assessments of strength and mobility. The long-term goal is to develop a competitively funded research program to optimize gait rehabilitation strategies based on neural substrates of walking impairment and recovery after neurologic injury. The overall objectives in this application are to assess study protocol feasibility and investigate relationships between select biomarkers and walking recovery to provide strong justification for a larger study on predictors of independent walking after stroke. The proposed objectives will be pursued through the following specific aims: 1) Assess feasibility of a larger study and develop methods for telehealth data collection; 2) Establish baseline levels of biomarkers (clinical, neuroimaging, blood) and average change over time; and 3) Elucidate relationships between baseline levels of biomarkers and walking gains across time in persons after stroke. A longitudinal, observational study design will be utilized for this study. Thirty-five persons with acute (<3 days) stroke will be recruited from the local medical center. Select inclusion criteria include presence of new lower limb weakness and assistance for walking; select exclusion criteria include cerebellar stroke and contraindications to MRI. Subjects will undergo clinical evaluation within 3 days, 1, 4, 9, 12, and 26 weeks after the initial onset of stroke symptoms. MRI scans will occur 5-12 days and 12 weeks post-stroke, and blood draws 72 hours, 1 week, and 12 weeks post-stroke. To assess feasibility we will examine study processes, recruitment, resources, study management, and scientific assessment. To examine the role of acute clinical, neuroimaging, and physiological measures in predicting walking recovery, we will examine relationships between these measures and walking outcome at 12- weeks post-stroke. This study employs an innovative approach to investigate predictors of walking recovery after stroke. The proposed research is significant because it is expected to provide strong scientific support for future clinical trials designed to target therapies based on predicted functional potential. Ultimately, such knowledge has the potential of enhancing mobility gains and patient independence following stroke.