Muscle
Gluteus medius
Hip abductor and pelvic stabiliser
High-yield
Superior gluteal nerve; weakness → Trendelenburg sign (pelvis drops on the contralateral, unsupported side).
Overview
A fan-shaped muscle deep to gluteus maximus that abducts the thigh and, crucially, keeps the pelvis level during single-leg stance.
Reference facts
- Origin
External ilium between the anterior and posterior gluteal lines
- Insertion
Lateral surface of the greater trochanter of the femur
- Action
Abducts the thigh; steadies the pelvis in single-leg support; anterior fibres medially rotate
- Innervation
Superior gluteal nerve (L4, L5, S1)
- Blood supply
Superior gluteal artery
Clinical correlation
Superior gluteal nerve injury produces a positive Trendelenburg sign.