Origin: Gluteal surface of ilium, under gluteus maximus
Insertion: Greater trochanter of the femur
Artery: Superior gluteal artery
Nerve: Superior gluteal nerve (L4, L5, S1 nerve roots)
Action: Abduction of the hip; preventing adduction of the hip. Medial rotation of thigh.
Antagonist: Lateral rotator group
The Glutaeus medius is a broad, thick, radiating muscle, situated on the outer surface of the pelvis. Its posterior third is covered by the Glutaeus maximus, its anterior two-thirds by the gluteal aponeurosis, which separates it from the superficial fascia and integument. Itarises from the outer surface of the ilium between the iliac crest and posterior gluteal line above, and the anterior gluteal line below; it also arises from the gluteal aponeurosis covering its outer surface. The fibers converge to a strong flattened tendon, which isinserted into the oblique ridge which runs downward and forward on the lateral surface of the greater trochanter. A bursa separates the tendon of the muscle from the surface of the trochanter over which it glides.
Variations.—The posterior border may be more or less closely united to the Piriformis, or some of the fibers end on its tendon.