The term spinal cord injury (SCI) refers to any injury of the neural (pertaining to nerves) elements within the spinal canal. SCI can occur from either trauma or disease to the vertebral column or the spinal cord itself. Most spinal cord injuries are the result of trauma to the vertebral column. Such trauma can cause a fracture of bone or tearing of ligaments with displacement of the bony column. This causes a pinching of the spinal cord. The damage from the spinal cord injury can affect the nerve fibers sending and receiving of messages from the brain to the body’s systems that control sensory, motor and autonomic function below the level of injury.

Age at Injury:
SCI primarily affects young adults. Fifty-five percent of SCIs occur among persons in the 16 to 30 year age group, and the average age at injury is 31.8 years. Since 1973 there has been an increase in the mean age at time of injury. Those who were injured before 1979 had a mean age of 28.6 while those injured after 1990 had a mean age of 35.1 years.

Gender:
Overall, 81.7% of all persons in the national database are male. Although this four-to-one male to female ratio has varied little throughout the 25 years of the Model Systems data collection, since 1990, the percentage of males has decreased to 80.6% (from 81.8% in the 1970’s).

Anatomy and Physiology:
The spinal cord is the largest nerve in the body. Nerves are cord-like structures made up of nerve fibers. Nerve fibers are responsible for the communication systems of the body, which include sensory, motor, and autonomic functions. The nerve fibers within the spinal cord carry messages between the brain and the rest of the body. Because the spinal cord is such an important part of the nervous system, protective bone segments, called the vertebral column, surround it (see Figure A). Approximately 11,000 new cases of SCI occur each year.

The spinal cord goes through the center of the stacked vertebrae. These bones protect the spinal cord. The nerve fibers branch out from the spinal cord to other parts of the body.

Source: Spinal Cord Information Network
http://www.spinalcord.uab.edu