The spinal cord is the major bundle of nerves carrying impulses to and from the brain to the rest of the body. Rings of bone, called vertebrae, surround the spinal cord. These bones constitute the spinal column or back bones.
Spinal cord injury is the result of a direct trauma to the nerves themselves or indirect damage to the bones and soft tissues and vessels surrounding the spinal cord.
Spinal cord damage results in a loss of function, such as mobility or feeling. In most people who have spinal cord injury, the spinal cord is intact. Spinal cord injury is not the same as back injury, which may result from pinched nerves or ruptured disks. Even when a person sustains a break in a vertebra or vertebrae, there may not be any spinal cord injury if the spinal cord itself is not affected.

Causes of Spinal Cord Injury
Spinal cord injuries may result from falls, diseases like polio or spina bifida (a disorder involving incomplete development of the brain, spinal cord, and/or their protective coverings), motor vehicle accidents, sports injuries, industrial accidents, and assaults, among other causes. If the spine is weak because of another condition, such as arthritis, minor injuries can cause spinal cord trauma.