Piriformis syndrome is a condition in which the piriformis muscle, located in the region of the buttocks, has spasms and causes pain in the buttock area.The piriformis muscle can also irritate the nearby sciatic nerve, and cause pain, numbness and tingling along the back of the leg and in the foot (similar to sciatic pain).
The piriformis muscle
The piriformis muscle is a small muscle located in the deep part of the buttocks (behind the gluteus maximus).
The piriformis muscle:
- Begins at the bottom of the spine and connects to the upper surface of each femur
- Works to assist in hip rotation and leg twist and foot out
- Runs diagonally, with the sciatic nerve running vertically directly below (although in some people, the nerve may run through the muscle).
Causes of Piriformis Syndrome
The exact causes of pyriform syndrome are unknown. Possible causes include:
- Muscle spasms in the piriformis muscle, either by irritation of the piriformis muscle itself or by irritation of a nearby structure such as the sacroiliac or hip joint
- Contraction in response to injury or spasm
- Inflammation of the piriformis muscle due to injury or spasm
- Bleeding in the piriformis muscle area.
Any of these problems, or a combination of these, can affect the piriformis muscle (and cause pain in the buttocks) and can affect the adjacent sciatic nerve (and cause pain, tingling, or numbness in the back of the thigh, calf, Or foot).
Symptoms and diagnosis of pyriformis syndrome
There is no simple diagnostic test for pyriform syndrome that causes irritation of the sciatic nerve. The condition is primarily diagnosed based on the patient’s symptoms and a physical examination, and after excluding other possible causes for the patient’s pain.
Symptoms of Piriformis syndrome
Patients often describe acute tenderness in the buttocks and pain similar to sciatica that runs down the back to the back of the thigh, calf, and foot. Typical pyriform syndrome symptoms may include:
- A dull pain in the buttocks
- Pain that descends through the back of the thigh, calf and foot (sciatica)
- Pain when climbing stairs or slopes
- Greater pain after sitting for a long time
- Range of reduced mobility in the hip joint
Symptoms of pyriform syndrome often worsen after sitting for a long time, walking or running, and may improve after lying on your back.