Almost 30 % of stroke survivors with initial severe arm impairment fail to achieve sufficient recovery of arm function to enable them to independently perform activities of daily living. Functional deficits can be improved by combining rehabilitation with promising new technologies. Myoelectrically controlled devices utilize the weak electrical signals generated by the affected muscles and amplify them to activate a motor in the device. The movement of the motor augments their own volitional movement in the joint associated with that motor. Hence, the device provides the user the support needed to move their paretic arm. a-Myopro is an adjustable myoelectrically controlled orthosis that facilitates movement of the paretic hand and elbow by providing assistance through four modes of movements. The a-Myopro user can train with a single mode, or multiple modes can be combined to allow for more complex training of individual or multi-joint movements. Thus, a- Myopro provides stroke subjects who have limited arm function a unique movement training paradigm that allows them to volitionally practice isolated arm movements that they otherwise cannot practice on their own. During the first weeks after the onset of stroke, the injured brain undergoes several neural mechanisms, a process known as neuroplasticity, that intend to reorganize the neural connectivity and repair the damaged tissue around the injury region. Several studies have revealed that rehabilitation during this acute period would enhance the functional outcome of the paretic arm presumably by modulating the heightened neuroplastic mechanism. Specifically, it has been suggested that novel interventions that enhance neuroplastic mechanisms of recovery are particularly needed for stroke survivors who are severely impaired. The rationale of this CDA1 proposal is to explore if the myoelectrically controlled device a-Myopro can be added to the acute rehabilitation of stroke subjects with severe arm deficits. The study will also investigate if application of a-Myopro would lead greater enhancement of clinical outcomes compared to standard care. Because neuroplasticity is heightened in the acute phase, the study aims to correlate the neurophysiological changes with the enhancement gained as a result of practicing with a-Myopro in this population. Thus, this study will test the premise that adding practice with a-Myopro to the acute rehabilitation of subjects with severe arm impairment acts as a novel rehabilitative tool that promotes the neuroplastic mechanisms of recovery to enhance clinical outcomes for these subjects. Preliminary data on chronic stroke subjects provides support for the central premise of this study. We have found that individuals with chronic stroke who receive 18 sessions of individualized practice using Myopro exhibit improvements in the clinical outcomes of the paretic arm. In this proposed study, to test my premise in the acute rehabilitation phase, ten subjects with acute ...