In 2017, Michel Roccati was in a motorbike accident that left his lower body completely paralyzed. In 2020, he walked again, thanks to a breakthrough new spinal cord implant. The implant sends electrical pulses to his muscles, mimicking the action of the brain, and could one day help people with severe spinal injuries stand, walk, and exercise. It builds on long-running research into using electrical pulses to improve quality of life for people with spinal cord injuries, including a 2018 study by the same team that helped people with partial lower-body paralysis walk again. "It was a very emotional experience,"...