Causes

Short-term stresses in the low back may be generated by heavy or prolonged lifting. Less commonly recognized stressors include awkward positioning. Back pain may begin with something as simple as bending over to pick up a piece of paper. This occurs because over half of our body weight is above the waist, and we mechanically disadvantage the spine with twisting and bending. Thus, even with no weight, enough force is generated to precipitate injury.

The back also undergoes stress with certain positions. Prolonged sitting or staying in the same position gradually fatigues the back, often causing discomfort or pain. This physical and structural fatigue can produce symptoms or add to the likelihood of precipitating injury.

Another precipitator of low back pain can come from emotional stress. The back in general, especially the shoulders and lower back, are regions where stress and anxiety produce tension that can frequently lead to pain.

Diet also plays a role as does smoking. As in so many other things, health habits contribute to the risk of low back pain.

Back pain with corresponding symptoms, such as numbness or tingling in the leg or sciatica, may be the result of a disk putting pressure on the nerves that run through the spine. This happens in about 10 percent of back pain cases.

Most degenerative disk changes have nothing to do with low back pain. The back ages just as the rest of our bodies do. This starts early on, possibly as early as our teens, and progresses each decade thereafter. This aging is frequently accelerated by heavier lines of work but also may be hastened by things such as inactivity and deconditioning.

By the time we enter our thirties, most of us have clearly definable aging changes in the low back. These are frequently called degenerative disk changes. These changes may include such things as disk herniations, which are present even in those who have no symptoms. In fact, by the age of 40, there is a 50 percent chance that you will have a disk herniation, even if you have never had back pain symptoms. Thus, degenerative disk changes and even disk herniations are signs of normal aging of the spine.