The piriformis is a small muscle located between the sacrum and the top of the femur, behind the glute muscles. It is responsible for rotating the hip and turning the leg and foot outwards when standing and inwards when the hip is flexed in a sitting position. The piriformis runs diagonally downwards and the sciatic nerve runs vertically behind the muscle. In small percentage of the population the sciatic nerve actually runs through the piriformis.
Piriformis syndrome occurs when spasms, tightness or swelling in the piriformis muscle cause buttock pain. In some cases the muscle irritates the sciatic nerve resulting in pain and even tingling down the leg and into the foot.
Symptoms of piriformis syndrome include one or more of the following:
Pain in the buttock area which increases when going uphill or upstairs
Pain down the back of the leg above and below the knee
A worsening of symptoms after prolonged sitting
A feeling of stiffness in the hip
Treatment for piriformis syndrome include massage, soft tissue therapy and a programme of stretching.