Gluteus Minimus

Introduction

Introduction to Gluteus Minimus

The gluteus minimus is the smallest and deepest of the three gluteal muscles. It is a fan‑shaped muscle situated deep to the gluteus medius on the lateral surface of the ilium. Despite its size, it plays a vital role in hip abduction, medial rotation, and, most critically, pelvic stabilisation during the single‑leg stance phase of gait. The tendon of the gluteus minimus, along with that of the gluteus medius, is a component of the hip’s ‘rotator cuff’ and is a common source of lateral hip pain when degenerative tears or tendinopathy occur.

Study

1. Origin and Insertion

The gluteus minimus originates from the external surface of the ilium between the anterior and inferior gluteal lines. The muscle fibres converge into a tendon that inserts on the anterior border of the greater trochanter of the femur. A bursa lies between the tendon and the bone.

2. Relations

Superficially, the gluteus minimus is covered by the gluteus medius. The superior gluteal nerve and the deep branch of the superior gluteal artery run in the plane between the minimus and medius. Anteriorly, it is related to the tensor fasciae latae. Posteriorly, it is related to the piriformis. Inferiorly, it is near the capsule of the hip joint.

3. Nerve Supply

The gluteus minimus is innervated by the superior gluteal nerve (L4, L5, S1), which enters the muscle on its deep surface.

4. Blood Supply

The deep branch of the superior gluteal artery, a branch of the internal iliac artery, supplies the muscle. Venous drainage follows the corresponding veins into the internal iliac vein.

5. Actions

The gluteus minimus abducts the hip and is a powerful medial (internal) rotator. Its anterior fibres assist in hip flexion, while the posterior fibres may assist in extension. Its most critical function is pelvic stabilisation during the stance phase of gait: it contracts to prevent the opposite side of the pelvis from dropping.

6. Functional and Clinical Relevance

Together with the gluteus medius, the minimus maintains a level pelvis when walking. Weakness leads to a positive Trendelenburg sign and a compensatory Trendelenburg gait (lateral trunk lean). Degenerative tears and tendinopathy of the gluteus minimus tendon are common causes of greater trochanteric pain syndrome. Tears may be partial or full‑thickness and can be repaired surgically. The muscle is also a landmark for the safe zone for intramuscular injections (upper outer quadrant of the buttock).

Summary

Summary of Gluteus Minimus

The gluteus minimus is the deepest gluteal muscle, originating from the ilium between the anterior and inferior gluteal lines and inserting on the anterior greater trochanter. Innervated by the superior gluteal nerve and supplied by the superior gluteal artery, it abducts, medially rotates, and stabilises the pelvis. Tendinopathy and tears are common in lateral hip pain, and weakness produces a Trendelenburg gait.