You fall, but your arms protect your head and chest. You'll be black and blue, but nothing more. Here, in less that a millisecond, the entire nervous system, from the brain on down, joined forces to make a brilliant, if not graceful, maneuver. When you injure your spinal cord, its bundle of nerves become swollen, bruised, or severed - resulting in a lack of communication between nerve pathways. Your nerves are damaged and your new situation is usually permanent.
Peripheral nerves can no longer send messages that require immediate action.
Like a short-circuit or a blown fuse, the spinal column at the place of impact on down remains silent. Nor can the brain order a leg to move, away, up, down, across. The leg receives no messages, no sensations. The severity of this silence depends on the site of spinal cord injury. Bowel and bladder capabilities will be affected.