It’s a tiny muscle with a big reputation. The piriformis is a small, deep muscle in the buttock.

It helps rotate your hip. Its primary action changes depending on your hip position.

The sciatic nerve usually passes underneath it. But anatomy varies, and in some people the nerve has different relationships with the muscle.

It connects your sacrum to your femur. So it literally bridges the pelvis and thigh.

It’s part of a team. The piriformis is one of the deep lateral rotators of the hip, working alongside muscles like the obturator internus and gemelli.