What is the sciatic nerve?

The sciatic nerve is the largest nerve in the entire body. It is not a single nerve but a collection of nerves that exit the lower lumbar spine and the sacrum then combine to form the sciatic nerve. The sciatic nerve runs down the back of the leg and into the foot branching out along the way to provide innervation to the tissues throughout the leg. Sciatica has many different causes and some of them can be more serious than others. A comprehensive exam will reveal the cause of the butt or leg pain and lead to proper treatment.


1. Lumbar Disc Herniation

When a disc herniation occurs there are two main factors that cause nerve pain. As the annular fibers break chemical irritants are released triggering pain and the inflammatory process. This increases pressure in the small area when there nerve roots reside causing nerve pain locally and into the involved limb. Secondarily, when the disc herniates it causes direct pressure on the nerve root. These two factors can cause low back pain, muscle spasticity, limb pain, numbness, and loss of motor function in the affected leg. At Comprehensive Chiropractic we use a flexion distraction table and a decompression table to help reduce the disc buldge.

2. Lumbar Foraminal Stenosis

Stenosis most often affects older adults and can cause sciatic pain. This occurs when the neural foramina (small hole) through which the nerve roots pass becomes smaller. This most commonly occurs due to degeneration of the disc and vertebra. This process closes down the foramen and thus applies pressure to the nerve roots causing symptoms in the leg.

3. Spondylolisthesis

A spondylolisthesis is a condition in which the vertebra one vertebra slips forward on the adjacent vertebra. When the vertebra is displaced, it can cause compression on the spinal nerves that exit in that area. This compression causes the leg symptoms associated with sciatica.

4. Piriformis Syndrome

The piriformis muscle is located deep in the buttock area that attaches the sacrum to the femur. The sciatic nerve runs directly under this muscle and in a small percentage of the population actually pierces through the muscle. When the piriformis muscle becomes tight or spastic it causes compression on the sciatic nerve and thus the leg symptoms that occur with sciatica.



5. Spinal Tumors

Spinal tumors are an abnormal growth of tissue that can be either benign or cancerous. Though they are rare, when a tumor occurs in the lumbar spine they can compress the spinal cord, nerve roots, or vertebra in that area and causing sciatica leg symptoms.



6. SI joint dysfunction

The Sacroiliac joint is one of the joints that connects your pelvis to your spine. You have two SI joints one on each side of the sacrum. When this joint becomes dysfunctional it can refer pain down the leg that is very similar to sciatica but not a true lesion of the sciatic nerve.

If you or someone you know is experiencing sciatica please visit Comprehensive Chiropractic to find out the cause of your sciatica and all of your treatment options.