The main functions of the lumbar spine are to protect the spinal nerves and facilitate a great part of the movement of the trunk.
The movement and loads cause adaptive changes of the tissue throughout life. These changes include loss of tissue elasticity, formation of osteophytes and calcification of the ligaments. As a result, the structures surrounding the spinal canal increase in volume and at the same time reduce the space available for nerve roots.
Degenerative changes are a physiological response of the body during the life of an adult. Imaging techniques (x-rays, computed tomography, and nuclear magnetic resonance) show these changes in different ways, depending on the person's age and activities. Many of these changes can be asymptomatic and unknown to the person. The presence of corresponding symptoms (mainly back pain) depends on the extent and location of the degeneration and the person's own anatomy.
Not all degenerative changes that can be detected with imaging techniques are symptomatic or need treatment. Sometimes this fact makes it difficult to detect the origin of the pain, since degenerative changes can be spread (and observed) along the entire lumbar spine, but only one of them can cause pain.