Anatomy
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
