Origin
- Front of the middle 3 pieces of its own half of the Sacrum, Lateral Mass of Sacrum extending medially between the Anterior Sacral Foramina
- Emerging Sacral Nerves and Sacral Plexus lie on the muscle
- Runs transversely to the Greater Sciatic Foramen
- In the buttock:
- Upper border lies alongside Gluteus Medius
- Lower border lies above the Superior Gemellus
- Converges into a rounded tendon inserted into the medial surface of the upper border of the Greater Trochanter
- Pelvic surface of muscle and Sacral Plexus covered by Pelvic Fascia attached to the Sacral Periosteum at the margin of the muscle Surface Marking
- Lower border of Piriformis – midpoint of a line between the Posterior Superior Iliac Spine (indicated by an overlying dimple on the surface of the back) and the tip of the Coccyx to the Tip of the Greater Trochanter Nerve Supply
- Anterior rami of S1 and S2
