What causes lumbar spinal stenosis?
Degeneration of the spine
Degeneration of the spinal column is a normal process to which everyone is prone to some degree. Some people naturally have narrower spinal canals than others.
When the spine begins to degenerate, the bands (ligaments) between the vertebrae thicken. In addition, the small facet joints, which overlap and connect the vertebral arches on the back of the spine, enlarge (which is to say they become wider and flatter). As a result, the nerve roots will have less space, especially in the small groove where the nerve roots leave the spinal canal. In some cases, a bulging intervertebral disc may contribute to the narrowing of the spinal canal.