Piriformis syndrome is characterized by pain caused when the piriformis muscle impinges the sciatic nerve. The piriformis muscle runs from the sacrum to the greater trochanter, which is the outer part of upper femur. Pain may be felt in the affected buttock, thigh and leg because the pain travels within the distribution of the sciatic nerve. Spasm or irritation of the piriformis muscle can impinge the sciatic nerve and cause pain. We can help you manage pain with injections.