Gluteus Medius and Minimus
On this page
Direct answer
Gluteus medius and gluteus minimus are the fan-shaped abductors of the hip lying deep to gluteus maximus, arising from the gluteal surface of the ilium between its gluteal lines. Gluteus medius is inserted into the lateral surface of the greater trochanter and gluteus minimus into its anterior surface. Both are supplied by the superior gluteal nerve (L4–S1); they abduct and medially rotate the hip and, most importantly, stabilise the pelvis during walking, so their paralysis produces a positive Trendelenburg sign and a waddling gait.
What you must remember
- Gluteus medius: origin from the ilium between the anterior and posterior gluteal lines (and the iliac crest); insertion into the lateral surface and posterosuperior angle of the greater trochanter; its posterior part laterally rotates the hip.
- Gluteus minimus: the smallest and deepest gluteal muscle; origin from the ilium between the anterior and inferior gluteal lines; insertion into the anterosuperior angle/anterior surface of the greater trochanter with a trochanteric bursa intervening.
- Nerve supply: superior gluteal nerve (L4, L5, S1), which leaves the pelvis above piriformis with the superior gluteal vessels and also supplies tensor fasciae latae; the vessels run between the two muscles.
- Actions: abduction of the hip; anterior fibres medially rotate; during standing on one leg their contraction holds the pelvis level by checking the drop of the opposite side.
- Trendelenburg sign: when the patient stands on the affected leg, the pelvis falls towards the unsupported side — positive in superior gluteal nerve palsy, polio, hip dislocation, coxa vara or an unstable femoral neck fracture.
- Trendelenburg gait: the trunk lurches towards the affected side during its stance phase to shift the centre of gravity over the weak abductors — a waddling trendelenburg gait when bilateral.
- Clinical importance: the muscles and the nerve are endangered in misplaced gluteal injections and in hip surgery (direct lateral approaches); bursitis over the greater trochanter mimics hip joint disease.
Common confusion
Do not attribute the Trendelenburg sign to gluteus maximus weakness — it tests the abductors, medius and minimus, through the superior gluteal nerve. Equally, do not confuse Trendelenburg gait (trunk lurch towards the affected side) with the gluteus maximus gait (backward lean). Remember that the test can be falsely positive when the hip itself is dislocated or the femoral neck is fractured, because the abductors' lever arm is lost even with intact nerves.
Exam-focused takeaway
This is a favourite viva and MCQ pair: quote the superior gluteal nerve roots, the muscles it supplies (medius, minimus, tensor fasciae latae — all abductors), and explain the mechanics of the Trendelenburg sign and compensatory gait. Theory answers should contrast the effects of superior and inferior gluteal nerve injuries side by side.
Frequently asked questions
What is the nerve supply of gluteus medius and minimus?
The superior gluteal nerve (L4, L5, S1), the only nerve to leave the greater sciatic foramen above piriformis. It also supplies tensor fasciae latae, so all three abductors are paralysed together.
Where do the two muscles originate and are inserted?
Medius arises from the ilium between the anterior and posterior gluteal lines and is inserted into the lateral surface of the greater trochanter; minimus arises between the anterior and inferior gluteal lines and is inserted into the anterior surface of the greater trochanter.
What is the Trendelenburg sign?
When standing on one leg, the normal abductors of the weight-bearing hip hold the pelvis level. If they are weak or the hip is unstable, the pelvis drops on the unsupported side — a positive sign, seen in superior gluteal nerve palsy, poliomyelitis and hip dislocation.
How does the Trendelenburg gait appear?
The patient lurches the trunk towards the affected side during stance on that limb, shifting body weight over the weak abductors. Bilateral involvement, as in congenital hip dislocation, produces a waddling gait.
Which arteries run between the two muscles?
The deep branch of the superior gluteal artery runs between gluteus medius and minimus, supplying both and anastomosing around the greater trochanter.