Piriformis
Hips & glutes
Deep muscle — it lies under other muscles. X-ray makes the muscles over it see-through.
- Origin
- Front surface of the sacrum
- Insertion
- Upper border of the greater trochanter
- Action
- Laterally rotates the hip and stabilises the joint
- Nerve supply
- Nerve to piriformis (S1–S2)
The best-known deep hip rotator, running from the sacrum to the top of the femur under the gluteus maximus. The sciatic nerve usually passes just below it.
Piriformis anatomy page →