The spine provides structure and support to the body. Without a spine, an individual would not be able to stand, bend or even move.

The spine is made up of block–shaped bones called vertebrae that are stacked on top of each other to form a column. At birth, a person typically has 33 vertebral bones. However, some vertebrae in the lower back fuse so that by adulthood there are 26 vertebrae. The spine is divided into several regions:

• Cervical:  seven vertebrae located in the neck 
• Thoracic: 12 vertebrae located in the upper back
• Lumbar:  five vertebrae located in the lower back

Below the lumbar vertebrae is the sacrum. This triangular bone makes up the back part of the pelvis. In children, the sacral spine begins as five vertebrae that eventually fuse into the single adult bone.

The sacral region also contains the coccyx (tailbone), which is at the bottom of the spine. The coccyx begins as several vertebrae, usually four, that fuse into one adult bone. The sacral region also contains the nerves that control bowel and bladder function and provide sensation to the pelvic area.

Intervertebral discs separate most of the vertebrae. These tough but elastic discs act as shock absorbers between the vertebrae, shielding the bones from the impact of activities such as jumping or certain forms of exercise. They degenerate as a person ages.

Ligaments and tendons also work together to connect bones to bones and bones to muscles. There are also a number of joints in the spinal column that connect the vertebrae and give the body flexibility to move.

The vertebral column is curved at various points to help align the head with a vertical line through the pelvis. The normal curve of the spine is shaped like an “S,” allowing the weight of the body to be evenly distributed.

The main purpose of the vertebral column is to support the weight of the head and trunk and to provide protection for the spinal cord. The spinal cord is an extension of the brain, and all information from the brain travels through the spinal cord to nerve fibers that stimulate the rest of the body. This pathway of information is necessary for bodily functions (breathing, heartbeat) sensations and movement.

Developmental problems, everyday stresses and sudden trauma can cause many spinal disorders. These include scoliosis, herniated discs, sciatica, arthritis, spinal stenosis, osteoporosis, fractures, spinal cord injuries and whiplash. Sometimes these conditions are minor, temporary or easily treated, but in other cases they can cause chronic pain and disability.