About the Back and Back Problems

Understanding Your Body

Understanding Your Body provides easy-to-understand explanations of body systems and disease conditions. This material can be used for patient education, life sciences curriculum development, or to enhance public understanding of general health concepts. Permission for such use is not required, but citation as to source is requested. The information provided is derived from Consumer Versions of Clinical Practice Guidelines, sponsored by the Agency for Health Care Policy and Research, from 1992 to 1996.

The human spine (or backbone) is made up of small bones called vertebrae. The vertebrae are stacked on top of each other to form a column. Between each vertebra is a cushion known as a disc. The vertebrae are held together by ligaments, and muscles are attached to the vertebrae by bands of tissue called tendons.

Openings in each vertebra line up to form a long hollow canal. The spinal cord runs through this canal from the base of the brain. Nerves from the spinal cord branch out and leave the spine through the spaces between the vertebrae.

The lower part of the back holds most of the body's weight. Even a minor problem with the bones, muscles, ligaments, or tendons in this area can cause pain when a person stands, bends, or moves around. Less often, a problem with a disc can pinch or irritate a nerve from the spinal cord, causing pain that runs down the leg, below the knee, called sciatica.

Muscles of the Back and Spine
Image depicting the Sciatic nerve and surrounding bones and back muscles. Image of lower back vertebra, discs, Spinal cord and nerve leaving the Spinal canal.

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Current as of November 2007
Internet Citation: About the Back and Back Problems: Understanding Your Body. November 2007. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/patients-consumers/prevention/understanding/bodysys/edbody1.html