Overview

Gluteus medius arises from the outer surface of the ilium between the anterior and posterior gluteal lines, below the iliac crest. It converges on the lateral surface of the greater trochanter. Its posterior third is covered by gluteus maximus, but its anterior two-thirds lie superficially under the gluteal aponeurosis and can be felt below the iliac crest.

With gluteus minimus and TFL it abducts the thigh. Its most important job, however, is to stabilise the pelvis during gait. As the opposite foot lifts off the ground, the abductors of the stance limb contract strongly to stop the pelvis tilting toward the unsupported side. Its anterior fibres medially rotate the thigh and its posterior fibres weakly laterally rotate it. It is supplied by the superior gluteal nerve (L4–S1), which leaves the pelvis above piriformis with the superior gluteal vessels and runs between gluteus medius and minimus.

Anatomy

Origin: External surface of the ilium between the anterior and posterior gluteal lines.
Insertion: Lateral surface of the greater trochanter of the femur.
Action: Abduction and medial rotation of the thigh; stabilises the pelvis on the stance limb.
Innervation: Superior gluteal nerve.
Nerve roots: L4–S1
Arterial supply: Superior gluteal artery (deep branch).
Relations: Superficial to gluteus minimus, with the superior gluteal neurovascular bundle in the plane between them. Partly covered by gluteus maximus posteriorly.

Function

Abducts the thigh
Keeps the pelvis level in single-leg stance and gait
Medially rotates the thigh (anterior fibres)

Clinical significance

Trendelenburg sign

Weakness of gluteus medius (or a superior gluteal nerve lesion) causes the pelvis to drop on the contralateral side when standing on the affected leg. The resulting gait is waddling (bilateral) or compensated with a lurch of the trunk toward the affected side.

Greater trochanteric pain syndrome

Gluteus medius and minimus tendinopathy (the "rotator cuff of the hip"), often with trochanteric bursitis, causes lateral hip pain on lying on that side and on stairs. It is commoner in middle-aged women.

Compiled from standard anatomy and physiology references — see the Muscular System sources. For education only; not medical advice.