Sensorimotor Integration by Targeted Priming in Muscles with Electromyography-Driven Electro-vibro-feedback in Robot-Assisted Wrist/Hand Rehabilitation after Stroke

Restoring precise muscular control in the poststroke wrist/hand (W/H) demands sensorimotor integration to correct compensatory neuroplasticity. However, current rehabilitation robots inadequately modulate ascending somatosensory pathways from specific muscles. This study developed an electromyography (EMG)-driven soft robot with electro-vibro-feedback (EVF-robot) for targeted somatosensory priming in W/H muscles. This system integrates (a) focal vibratory stimulation and neuromuscular electrical stimulation for recruiting the somatosensory pathways of the targeted W/H flexors and extensors; (b) an EMG-driven control algorithm for strengthening the voluntary motor control of a driving muscle; and (c) robot assistance to achieve coordinated joint extension and flexion. In a single-arm trial with 20 sessions, 15 chronic stroke participants assisted by the system achieved significant improvements in voluntary W/H behavioral control, somatosensory feedback, and intermuscular coordination in the paretic upper limb (P < 0.05). During their W/H extension, the cortical peaks of corticomuscular coherence shifted contralaterally for W/H extensors, and the ascending corticomuscular coherence from W/H flexors increased (P < 0.05). These improvements persisted at the 3-month follow-up. The findings provide preliminary evidence that sensorimotor integration training with the EMG-driven EVF-robot may modulate compensatory neuroplasticity and facilitate improvements in coordinated motor control of the distal joints in individuals with chronic stroke.