The Intervertebral Discs

Epidemiological studies have shown that smoking, is a risk factor for intervertebral disc herniation because it causes a significant decrease in oxygen in the avascular disc by vasoconstriction (Foster). Heavy coughing can also cause disc herniation. Sitting unsupported increases the pressure on intervertebral discs, and may contribute to disc herniation. Driving is a risk factor for disc herniation because of the continuous vibration to the spine, and truck drivers are particularly prone to the problem. A weakened annulus is a prerequisite for disc herniation, and an annular tear or weak spot can result from repetitive normal stress from customary activities and physically stressful activities. Although bone has no pain receptors, the discs have associated neurovascular elements, which include pain fibers (Foster). Lower back pain is a common symptom of disc herniation along with stiffness and diminished stability of the spine, unilateral leg pain, numbness,