http://www.youtube.com/v/JxTqN6oiGL8

Old man tries out a brand new technology – The Self Walker – which enables disabled people to get up from their wheelchairs and magically allow them to walk. It's a miracle! Unfortunately, the machine hasn't had all its kinks worked out yet and it starts to malfunction. Poor grandpa's legs kick and flail about out of control, as prank victims helplessly try to rework the device.