Piriformis Syndrome


Piriformis syndrome is a condition in which the piriformis muscle, located in the buttock region, spasms and causes buttock pain. The piriformis muscle can also irritate the nearby sciatic nerve and cause pain, numbness and tingling along the back of the leg and into the foot (similar to sciatic pain

Why it Occurs

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 and turning the leg and foot outward
• Runs diagonally, with the sciatic nerve running vertically directly beneath it (although in some people the nerve can run through the muscle).
The exact causes of piriformis syndrome are unknown. Suspected causes include:
• Muscle spasm in the piriformis muscle, either because of irritation in the piriformis muscle itself, or irritation of a nearby structure such as the sacroiliac joint or hip
• Tightening of the muscle, in response to injury or spasm
• Swelling of the piriformis muscle, due to injury or spasm
• Bleeding in the area of the piriformis muscle.
Any one or combination of the above problems can affect the piriformis muscle (causing buttock pain) and may affect the adjacent sciatic nerve (causing pain, tingling, or numbness in the back of the thigh, calf, or foot).


Most commonly, patients describe acute tenderness in the buttock and sciatica-like pain down the back of the back of the thigh, calf and foot. Typical piriformis syndrome symptoms may include:
• A dull ache in the buttock
• Pain down the back of the thigh, calf and foot (sciatica)
• Pain when walking up stairs or inclines
• Increased pain after prolonged sitting
• Reduced range of motion of the hip joint
Symptoms of piriformis syndrome often become worse after prolonged sitting, walking or running, and may feel better after lying down on the back.


In addition to basic stretching, a comprehensive physical therapy and exercise program can be developed for each patient’s individual situation. A number of stretching exercises for the piriformis, hamstrings and hip extensors may help decrease the painful symptoms along the sciatic nerve and return the patient’s range of motion. The basic stretches include:
Piriformis stretch
There are a number of ways to stretch ones piriformis muscle. Two simple ways include:
• Lie on ones back with both feet flat on the floor and both knees bent. Pull the right knee up to the chest, grasp the knee with the left hand and pull it towards the left shoulder and hold the stretch. Repeat for each side.
• Lie on the back with both feet flat on the floor and both knees bent. Rest the ankle of the right leg over the knee of the left leg. Pull the left thigh toward the chest and hold the stretch. Repeat for each side.
Each piriformis stretch should be held for 5 seconds to start, and gradually increased to hold for 30 seconds, and repeated three times each day

Hamstring stretch for sciatic nerve pain
Stretching the hamstrings (the large muscle along the back of each thigh) is important to alleviate any type of sciatic pain. There are a number of ways to stretch the hamstrings:
• Place two chairs facing each other. Sit on one chair and place the heel of one leg on the other chair. Lean forward, bending at the hips until a gentle stretch along the back of the thigh is felt, and hold the stretch.
• Lie on the back with both legs straight. Pull one leg up and straighten by holding on to a towel that is wrapped behind the foot until a mild stretch along the back of the thigh is felt.
Again, try to work up to holding each stretch for 30 seconds and repeat three times each day.

For severe sciatica pain from piriformis syndrome, an injection may be part of the treatment.
Piriformis injection
A local anesthetic and corticosteroid may be injected directly into the piriformis muscle to help decrease the spasm and pain. The purpose of an injection is usually to decrease acute pain to enable progress in physical therapy.
Botox injection
For persistent piriformis spasm that is resistant to treatment with anesthetic/corticosteroid injections, an injection of botulinum toxin (e.g. Botox®), a muscle weakening agent, may be useful. The goal of the injection is to help the muscle relax and help reduce pressure on the sciatic nerve.
The goal with both injections is to help the patient progress with stretching and physical therapy, so that when the effect of the injection is over the muscle will be remain stretched and relaxed.