what causes pyriformis syndrome
Piriformis Syndrome. Piriformis syndrome causes pain in the buttock which may radiate down the leg. It is due to the sciatic nerve being impinged by a tight piriformis muscle deep in the buttocks.he piriformis muscle is one of the small muscles deep in the buttocks that rotates the leg outwards. It runs from the sacrum bone at the bottom of the spine and attaches to the thigh bone or femur roughly near the outside crease of the buttocks.