The spinal column runs down the center of the back and is composed of several nerve cords surrounded by bony vertebrae. Each vertebra is separated by a disc which acts as a shock absorber. Numerous ligaments and muscles surround the spinal column. Because many of the forces affecting the body are exerted in this region, nearly any of these tissues or structures can become stretched or stressed and contribute to pain.
Back pain can arise from nerves in the back or from other tissues in the region.
Spinal stenosis, a narrowing of the space in the spine's central canal, is a common condition in older adults and may be associated with back and leg pain. Disc herniation, which is an injury to the intervertebral disc, is a more common condition for younger and middle-aged adults. Muscle weakness, strain or the inflammation of the small facet joints that connect each vertebra could also be culprits for back pain. In patients with osteoporosis, a condition most commonly seen in older women, a compression fracture may also be a source of pain. Compression fractures are caused by a collapse of the vertebrae.