The Sciatic Nerve is the main nerve that runs from the bottom of the spine and down the leg to the foot. Sciatica is the name given to the irritation or pressure upon this nerve. It is the largest nerve in the body and consists of a nerve network in the pelvis. It is formed from several lumbar spinal nerves. The sciatic nerve runs down each leg from the back of the pelvis and down the back of each thigh. At the knee joint, the nerve separates into two main branches, known as the tibial nerves and then proceeds down to the feet. It supplies the hip joint, many of the thigh muscles, the knee and ankle joints and all the muscles in the lower leg and foot, including the skin on the thighs and below the knee.
The most common cause of Sciatica is a prolapsed (slipped) intervertebral disc.
The spinal column consists of a number of vertebrae that are 'stacked up' and are separated by thick pads of tissue called discs. These act as shock absorbers to the vertebrae while we are continually moving our backs, through bending etc. Other names for Sciatica are slipped disc, prolapsed disc or herniated disc. The fibrous tissue that these discs consist of can become ruptured through heavy lifting or excessive bending. Any damage to these discs can result in the compression of the Sciatic Nerve, causing pain and discomfort (Appendix 1).
Dislocation of the hip and/or knee, certain infections and alcohol dependence may also be the cause of Sciatica.
In many cases however, it is damage to the disc that causes a protrusion (a bulge) and this causes a limitation of space between the discs. The sciatic nerve becomes trapped within this space and the compression of the nerve...