Pain related to the sciatic nerve is a very common condition. This is due to the compression of the sciatic nerve near the piriformis muscle. This can lead to pain in the leg, foot and buttocks depending on where and to what degree the compression is occurring. A piriformis block is an injection of anesthetic and steroid into the affected area with the goal of reducing irritation and inflammation. The injection is a deep muscle injection and pain from the injection may last a few days.