A power assistive device for hand rehabilitation that provides training of a combined movement of finger flexion-extension and forearm supination-pronation to a user. The power assistive device includes a hand brace and a base. The hand brace includes finger assemblies that adjustably connect to a platform, actuators that connect to the finger assemblies, and strain gauge sensors that connect to the finger assemblies and detect force signals generated by movement of the finger assemblies. The base removably connects to the hand brace and includes a forearm support, a C-shaped ring that includes C-shaped tracks formed along an inner circumferential surface of the C-shaped ring, a rotatable platform that moves along the C-shaped tracks, a mounting platform that connects to the rotatable platform, and an electromyography (EMG) sensor that attaches to the forearm of the user and senses EMG signals generated by movement of the hand of the user.