The piriformis is a muscle that needs to be mentioned for it often plays a role in back and posterior leg pain. The reason for this that the sciatic nerve either passes through or under the piriformis muscle so the tighter the piriformis the more pressure is placed upon the sciatic nerve which can lead to butt, thigh or leg pain.
The Sciatic Nerve can be common to back, buttock and back of the leg pain. This is due to where it is located and it’s pathway down the leg to the foot. The sciatic nerve is a large nerve the exists the back, runs down the buttock and back of the leg, then branches into two separate nerves that lead to the foot.