The new treatment uses a technique called transcutaneous electrical nerve stimulation, which involves strategically placing electrodes on the skin of the lower back. While receiving stimulation, the men's legs were supported by braces that hung from the ceiling. At first their legs only moved involuntarily, if at all. But they soon found they could voluntarily extend the distance their legs moved during stimulation. They doubled their range of voluntary motion after four treatment sessions.
Link to Original Source