The Facts
The spine is made up of bone segments called vertebrae. Vertebrae
have two parts - the cylinder-shaped vertebral bodies to the front and the boney
bridges making up the facet joints at the back. Most of the spine is flexible
enough to let people bend, stretch, and lift. Between the bones of the spine
are small discs that are hard on the outside, and soft and jelly-like on the
inside. The spinal bones are connected by the facet joints at the back
and by the discs at the front. The nerves of the spinal cord run through the
spinal canal, which is just behind the vertebral bodies, and separate
into roots along the length of the spinal cord and at the tail end of the spine.
Some of them pass through the pelvis to become the sciatic nerves, which
pass down each leg. Problems with the vertebrae, joints, or discs can all cause
back disorders. Back disorders can cause mild to very severe backache.
About 75% to 85% of Americans will develop back pain at some time in their lives.
Though it hurts, back pain is rarely caused by a serious disease and usually
disappears in six to eight weeks. It often comes back, however, making it the
second most common reason people see doctors.