Understanding Your Back

Without a spine (backbone), your body wouldn't be able to remain upright or to bend, twist, or move with any flexibility.

It's your spine, the flexible column made up of 33 bones called vertebrae, that allows you to stand upright and to walk. In addition to providing support to the body, the spinal column protects the spinal cord. The function of the spinal cord is to relay messages (nerve impulses) from the brain to the body and from the body to the brain.

Each vertebra has an opening that runs up and down the spine.

Together these openings form the spinal canal that contains the spinal cord. All movements of your body, including your arms and legs, and all sensations are relayed through the spinal cord. There's also a small opening between each vertebra called a foramen where the spinal nerves leave the spinal canal and go to the rest of your body.

Taking care of your spine requires an understanding of back anatomy.

Illustration of spine and supporting muscles

The bones of the spine—the vertebrae—begin at the neck. The spine has three curves, which serve to support the body during movement, to keep the body balanced, and to help us to stand upright.

The spine can be divided into these sections:

  • The cervical spine is composed of the first seven of the 33 vertebrae. You can find them by touching the upper back and feeling the bony protrusions. The cervical spine supports your head.

  • The thoracic spine is composed of 12 lumbar vertebrae. This section of the spine helps to protect the organs in your chest and serves to anchor your ribs.

  • The lumbar spine is composed of five vertebrae located in the lower back. This part of the spine provides the most power and has the most motion.

  • The sacrum and the coccyx are located at the bottom of the spine. The sacrum is formed before birth by five naturally fused vertebrae and connects the spine to the pelvis and lower half of the skeleton. At the end of the spinal column is the coccyx or tailbone.

Illustration of lower spine, disks, and nerves

Between each vertebra is a spongy cushion called a disk. These disks absorb shock when the body moves. They also cushion the spinal bones and help keep the back fit.

Your spine is supported by strong back muscles, which help to hold the vertebrae and disks in correct alignment. In addition, strong abdominal, hip, and leg muscles help to reduce strain on your back.