The piriformis is one of the muscles of the deep group of muscles within the gluteal region. It is the most superior muscle of the deep gluteal muscles.
The gluteal region consists of two groups of muscles:
- Deep group: small muscles which mainly laterally rotate the femur at the hip joint. These include the piriformis, obturator internus, gemellus superior, gemellus inferior, and quadratus femoris.
- Superficial group: larger muscles which cause abduction and extension of the femur at the hip joint. These include the gluteus maximus, gluteus medius, gluteus minimis and the tensor fascia latae.
- Anterior portion of lateral process of sacrum
- Gluteal surface of ilium at border of greater sciatic notch
- Lateral rotation of hip
- Assists abduction of hip when hip is flexed
- Piriformis nerve: L5,S1,S2
- Superior and inferior gluteal arteries
- Internal pudendal artery