A Reference for Patients
Two out of every three adults suffer from low back pain at some time. Back pain is the #2 reason adults visit a doctor, and the #1 reason for orthopaedic visits. It keeps people home from work and interferes with routine daily activities, recreation, and exercise. The good news is that for 9 out of 10 patients with low back pain, the pain is acute, meaning it is short-term and goes away within a few days or weeks. There are cases of low back pain, however, that take much longer to improve, and some that need evaluation for a possible cause other than muscle strain or arthritis.
Symptoms may range from muscle ache to shooting or stabbing pain, limited flexibility and/or range of motion, or an inability to stand straight.
What Structures Make Up the Back?[1]
The back is an intricate structure of bones, muscles, and other tissues that form the back, or posterior part of the bodys trunk, from the neck to the pelvis. At the center is the spinal column, which not only supports the upper bodys weight but houses and protects the spinal cord the delicate nervous system structure that carries signals that control the bodys movements and convey its sensations. Stacked on top of one another are about 30 bones the vertebrae that form the spinal column, also known as the spine. Each of these bones contains a roundish hole that, when stacked in line with all the others, creates a channel that surrounds the spinal cord. The spinal cord descends from the base of the brain and extends (in the adult) to just below the rib cage.
Vertebrae are bones that form the spinal column. Small nerves (roots) enter and come out from the spinal cord through spaces between the vertebrae. Because the bones of the spinal column continue growing long after the spinal cord reaches its full length in early childhood, the nerve roots to the lower back and legs extend many inches down the spinal column before exiting. This large bundle of nerve roots was dubbed by early anatomists as the cauda equina, or horses tail. The spaces between the vertebrae are maintained by round, spongy pads of cartilage called intervertebral discs that allow for flexibility in the lower back and act much like shock absorbers throughout the spinal column to cushion the bones as the body moves. Bands of tissue known as ligaments and tendons hold the vertebrae in place and attach the muscles to the spinal column.