you could not do before? when i park my car somewhere, and another car gets too close, i cannot get in between with my wheelchair. now i can stand up, walk, get into the car and get the chair back into the car. this is david when he first had his implant in 2017. stim on means electrical stimulation on. when it is turned off, he cannot move. back on, and he is able to walk again. nerves in the spinal cord send signals from the brain to the legs. some people are paralysed when the nerves are damaged through injury. in most cases, there is still a small signal to the legs, but it is too weak to create movement. the implant boosts the signal, enabling david to walk. it has also improved david's kite surfing. he can make slight movements with his feet to control the surfboard. even with his implant turned off. that is the wrong leg.