Stroke is a leading cause of adult disability, with more than 795,000 people having a stroke in the United States each year. Stroke survivors often experience loss of motor control and impaired function. Immediately after stroke, there is a time-limited window of heightened plasticity during which the greatest gains in recovery occur. Therefore, early intensive sensorimotor rehabilitation post-stroke is critical in improving functional outcomes and minimizing disability. As recommended in a national guideline, “rehabilitation therapy should start as early as possible, once medical stability is reached”. However, acute stroke survivors often receive little active training to improve mobility during their hospital stay and they are left alone during most of the day. Especially for those acute patients with no voluntary motor output (Manual muscle testing MMT=0), active motor training might be even less, partly due to a lack of rehabilitation protocols to detect potential motor recovering signals sensitively and facilitate neuroplastic changes. Although a number of rehabilitation devices have been developed for stroke rehabilitation, few of them is suitable for the critical period of early in-bed rehabilitation, especially for patients with MMT=0, to provide timely motor-sensory training during the critical time window early post stroke. To address this unmet clinical need, the proposed project will develop a novel wearable rehabilitation robot suitable for in-bed acute stage rehabilitation with guided motor relearning, passive and active motor-sensory rehabilitation early in the acute stage post-stroke including patients who are paralyzed with no motor output. We propose to develop the early acute stroke rehabilitation device suitable for severe motor impairment and evaluate the device through a clinical trial to conduct intensive daily motor-sensory rehabilitation on patients with acute stroke including those with MMT=0 or 1 during the earliest feasible periods (>24 hours after admission) and throughout their hospital stay, using a wearable rehabilitation robot. The long-term goals are to intervene early and facilitate sensorimotor recovery, reduce lower limb impairments, and improve balance and locomotion. In Phase I of the study, we will improve the hardware and software of a prototype wearable rehabilitation robot and make it suitable for in-bed early intensive rehabilitation of acute stroke survivors with severe ankle motor impairment to carry out the training: 1) guided motor relearning training under real-time feedback; 2) intelligent stretching for sensory stimulation and stiffness reduction; 3) game-based active movement training under robotic assistance and demonstration; 4) repeat the guided motor relearning in 1). A clinical trial will be conducted in Phase II on a study group receive the above 4-step training, while control group receives only passive ankle movement in the middle range of motion without stretching and active ankle movement without robotic assistance. The proposed study seeks to provide a much needed early in-bed sensory-motor training protocol applicable to severe motor impairment using a rehabilitation robot to facilitate neuroplastic changes in the critical period of early post stroke, which will likely promote earlier and better recovery and improve functional outcomes.