Targeted nerve stimulation restores single-finger movements in a person with tetraplegia

The loss of hand function is one of the most devastating impairments for individuals with paralysis. While current neurotechnologies can partially restore prehensile control, they fall short of enabling independent finger movements — an essential requirement for full hand dexterity. Achieving this level of precision demands highly selective activation of individual muscles or muscle groups. In this first-in-human study, we explored a novel approach in an individual with chronic tetraplegia. Our method combined targeted surgery to isolate functionally relevant branches of the median and radial nerves with custom intrafascicular electrodes to interface with them. By precisely stimulating motor fibers within these nerves, we successfully restored independent movement in four fingers, including the thumb. The combination of these movements allowed the recreation of the lateral, hook, and palmar grasps with smoothly modulated forces. Furthermore, the participant regained the ability to perform functional tasks, such as pouring water from a bottle. These findings hold significant promise for individuals with hand paralysis, paving the way for neurotechnologies that can bypass spinal cord injuries and restore fine motor control.