Quadriplegia is the paralysis of the body from the neck downwards, including the trunk, arms and legs. Paralysis generally occurs when there is an error in the communication between the brain and muscles due to spinal cord injury. This error results in a complete or partial loss of muscle function. Quadriplegia commonly results from injury between the cervical vertebrae C5 and C7. This leads to loss of function of breathing muscles and muscles controlling bowel and bladder movements. Function may be restored by intensive therapy in some cases.