The most common causes of lower back spinal pain are sprains, herniated discs, disc degeneration and sciatica, states the National Institute of Neurological Disorders and Stroke. Although sprains and strains cause the majority of back pain, they do not necessarily involve the spine.
Herniated, ruptured or degenerating discs in the spine cause lower back spinal pain, says the National Institute of Neurological Disorders and Stroke. Discs can become herniated in an injury that compresses the disc, causing it to bulge and rupture. This in turn puts pressure on the nerves. The vertebrae in the spinal column can also degenerate, meaning that the discs become less elastic and no longer cushion the back as it flexes and moves. Sometimes the sciatic nerve that runs down the spine and to the legs gets pinched in a vertebra, causing pain that radiates down the body.
Underlying conditions, such as arthritis, infections and cauda equina syndrome, can also cause lower back pain, explains the National Institute of Neurological Disorders and Stroke. Arthritis inflames the joints of the body, causing lower back pain. Sometimes the spinal column contracts infections, such as osteomyelitis or discitis, that occur in the vertebrae and intervertebral discs respectively. Cauda equina syndrome occurs when the material from a ruptured disc enters the spinal canal and exerts pressure on the lumbar and sacral nerve roots, leading to bowel and bladder incontinence. Lacking treatment, permanent neurological damage can occur.