MuscleGluteal region — deep
Piriformis
Latin: M. piriformis
Location: Gluteal
View the piriformis in 3DOrigin
Anterior sacrum (pelvic surface), sacrotuberous ligament.
Insertion
Superior border of the greater trochanter.
Action
Laterally rotates and abducts the extended hip; steadies the femoral head.
Nerve supply
Nerve to piriformis (S1–S2) — and in ~15% the sciatic nerve pierces the muscle.
Blood supply
Inferior gluteal and superior gluteal arteries.
Clinical relevance
Piriformis syndrome irritates the sciatic nerve under or through it — buttock pain with sciatica but no disc signs. It is the key landmark of the gluteal region: the superior gluteal vessels and nerve emerge above it, the sciatic and inferior gluteal nerves below.
Educational anatomy reference, not medical advice. About this content.