Sciatica: pain along the large sciatic nerve that runs from the lower back down to the leg.

When the pain begins to radiate down to the leg, a certain nerve will be affected. It is possible to have therapy aimed at a specific target. Sciatica is usually caused by pressure on the sciatic nerve from a herniated disc (also referred to as a ruptured disc, a pinched nerve, a slipped disk, etc.). The problem is often diagnosed as "radiculopathy", i.e. a disc protruded from its normal position in the vertebral column putting pressure on the radicular nerve (nerve root) connected with the sciatic nerve.

Disc anatomy

Discs are the spongy cushions between the bones of the spine, supplying mobility to the spinal column while protecting the bones from repeated stress. It is the constant strain put on the discs, especially when combined with a lack of muscles, leading to their proclivity to rupture.

The disc consists of a hard, fibrous shell, the annulus, surrounding a more spongy nucleus. Repeated stress and injury, combined with weight, posture, and genetics, as well as simple bad luck, may lead to the nucleus rupture through the anulus. The medical condition resulting from this is a herniated nucleus pulposus.

The disc spaces are named after the bones they are sandwiched in between. The lumbar spine consists of five bones or vertebrae ending at that part of the pelvis called the sacrum. When a disc ruptures, a piece of the nucleus will be pushed through the anulus at a very nerve root. The disc material will compress the nerve. As compressed nerves hurt, sitting or straining, or even coughing or sneezing, will put more pressure on the nerve, thus causing more pain.