Lower Back Issues

Piriformis Syndrome

Causes
The symptoms of sciatica come from irritation of the sciatic nerve. It’s still a mystery why the piriformis muscle sometimes starts to irritate the sciatic nerve. Many doctors think that the condition begins when the piriformis muscle goes into spasm and tightensagainst the sciatic nerve, squeezing the nerve against the bone of the pelvis.

In some cases, the muscle may be injured due to a fall onto the buttock. Bleeding in and around the piriformis muscle forms a hematoma. A hematoma describes the blood that has pooled in that area. The piriformis muscle begins to swell and put pressure on the sciatic nerve. Soon the hematoma dissolves, but the muscle goes into spasm.

The sciatic nerve stays irritated and continues to be a problem. Eventually the muscle heals, but some of the muscle fibers inside the piriformis muscle are replaced by scar tissue. Scar tissue is not nearly as flexible and elastic as normal muscle tissue. Thepiriformis muscle can tighten up and put constant pressure against the sciatic nerve.

Symptoms
Piriformis syndrome commonly causes pain that radiates down the back of the leg. The pain may be felt only on one side, though it is sometimes felt on both sides. The pain can radiate down the leg all the way to the foot and may be confused for a herniated disc in the lumbar spine. Changes in sensation and weakness in the leg or foot are rare. Some people say they feel a sensation of vague tingling down the leg.

Sitting may be difficult. Usually people with piriformis syndrome do not like to sit.When they do sit down, they tend to sit with the sore side buttock tilted up rather than sitting flat in the chair.