Bones and disks

THE DISKS The spinal disks absorb the impact of body weight and movements. Normally, they serve as efficient shock absorbers for a long lifetime. But some of us give them more load or shock than they can bear-through excessive body weight, excessive or improper load lifting, and neglect of good tone in the muscles of both back and abdomen which help to maintain good posture. There is no such thing as a "slipped" disk, although you hear the term often. What has happened to the victim of a so-called slipped disk is that the disk has been crushed or has worn out and a portion of it has been extruded. The ligaments and fibrous layers of the disk have weakened, and the nucleus has been pushed out from the center into the spinal canal, compressing the nerve roots that branch from the spinal cord at this level.

The disk most commonly undergoing such herniation is the one between the fourth and fifth lumbar (lower back) vertebrae. When this disk is affected, pain is usually felt down the back of the leg and even into the side of the foot. Disk herniation can occur gradually over a period of many years of strenuous jarring activity, or it can be caused by an accident like a fall. Effective treatment for disk herniation is available. It may be conservative, relying upon removal of pressure from nerve roots, use of a firm bed or bed board, traction, and medication. In some cases, surgery may be required. The wise thing, of course, is to prevent disk problems. One sensible measure is to keep body weight at the proper level. Another is to be careful in picking up heavy weights. And very much worthwhile is the maintenance of physical fitness through regular moderate exercise and the use of special exercises (see page 89) for strengthening back and abdominal muscles.