Piriformis syndrome - another irritation to the sciatic nerve

By: John P. Revord, MD
April 8, 2000

Piriformis syndrome and sciatica pain

Piriformis syndrome is a condition in which the piriformis muscle irritates the sciatic nerve and causes pain in the rear and may cause pain along the back of the leg and into the foot (similar to sciatica pain). Piriformis syndrome is most common among women, and is thought to be common among active individuals (such as runners and walkers).

While there is some controversy in the medical community, many health professionals believe that an accurate diagnosis and comprehensive management approach are critical to alleviate the sciatica type of pain caused by piriformis syndrome.

What is the piriformis muscle?

The piriformis muscle is a small muscle located deep in the rear (behind the gluteus maximus).

The piriformis muscle:

• Starts at the lower spine and connects to the upper surface of each femur (thighbone).

• Functions to assist in rotating the hip.

• Runs horizontally, with the sciatic nerve running vertically directly beneath it.

Piriformis syndrome can develop when the piriformis muscle becomes tight or spasms and places pressure on the sciatic nerve that runs beneath it. The pressure on the sciatic nerve can cause low back pain and/or pain that radiates to the rear and down the leg (similar to sciatica pain). From a technical standpoint, piriformis syndrome does not cause true sciatica (as sciatica is usually defined as a radiculopathy, or compression of a nerve root as it exits the spine). However, just like sciatica, piriformis syndrome can cause pain, numbness and tingling along the sciatic nerve, which runs down the back of the leg and into the foot.