A spinal cord injury is a physical disability. A spinal cord injury occurs when there is damage to the spinal cord which runs through the inside of the vertebral column. The purpose of the spinal cord is to relay nervous signals from the brain through the central nervous system and from there throughout the body. In other words, the brain initiates an action, the nerves carry the signal from the brain along the spinal cord and the central nervous system, and the muscles, joints, ligaments and tendons carry out the actions. When there is damage to the spinal cord, this pathway is interrupted. The signals are not able to be carried correctly from the brain to the rest of the body.
This can happen at various points along the spinal cord. The effect of this physical disability upon the body varies according to the level of the spinal cord which is affected by the injury. A spinal cord injury which occurs at a lower level of the spinal cord has a less significant effect than one which occurs higher up. This is because the parts of the body which are controlled by the nerves from the spinal cord extend out from roughly the same level as where they correspond to on the spine. For example, the muscles which control the chest, upper arms and neck are located high on the spinal column. An injury which affects these parts of the body has occurred at an upper part of the spinal column. It causes a higher degree of physical disability than a spinal cord injury which occurs lower on the spine.
