gluteus medius

A large fan-shaped thick muscle located in the posterior surface of the pelvis, extending from the ilium to the proximal femur.

(Functions)
• anterior part (alone): Flex and internally rotate the hip.
• posterior part (alone): Extend and externally rotate the hip.
• anterior and posterior parts together: Abduct the hip and stabilize the pelvis in the coronal plane.

(Blood supply)
• deep branch of superior gluteal artery
• trochanteric anastomosis

(Innervation)
• superior gluteal nerve (L4, L5, S1 nerve roots)

Cf. Trendelenburg's sign