Name

# Piriformis

Pronunciation

(piri-FOR-mus)

Origin/Proximal Attachment

Pelvic surface of sacrum

Insertion/Distal Attachment

Medial surface of greater trochanter (through greater sciatic foramen)

Action/Relevance

Externally rotates the thigh when extended

Abducts thigh when flexed

Innervation

Nerve to piriformis (S1, 2)

Notes

Lies in the same plane as glut medius

Often fuses its insertion with ob internus and the gemelli.