The electrical stimulator could one day be used to help people with paralysis to walk, as well as improve recovery from strokes, say researchers.
A device that sends an electrical "buzz" through the skin could allow people who were paralysed several decades ago to regain movement in their arms and hands.
The ARC-EX device sends an electrical current to the spinal cord through surface electrodes, increasing strength, sensation and ability to move in people with paraplegia.