Gluteus Maximus Muscle Anatomy

The gluteus maximus muscle is the most superficial gluteal muscle. It is the largest, heaviest, and most coarsely fibered muscle of the body. This muscle covers all of the other gluteal muscles, except for the anterosuperior third of the gluteus medius.

Gluteus Maximus Muscle Anatomy

The Gluteus maximus muscle has a wide origin, from posterior aspect of dorsal ilium, posterior to posterior gluteal line, posterior superior iliac crest, posterior inferior aspect of sacrum and coccyx and sacrotuberous ligament. It also has two insertion points, The superficial fibers insert into the iliotibial tract, and the deep fibers insert into the gluteal tuberosity of the femur between the adductor magus and vastus lateralis.

See Also: Hip Muscles Anatomy

The gluteus maximus slopes inferolaterally at a 45° angle from the pelvis to the buttocks. The fibers of the superior and larger part of the gluteus maximus and superficial fibers of its inferior part insert into the iliotibial tract and indirectly, via the lateral intermuscular septum, into the linea aspera of the femur. Some deep fibers of the inferior part of the muscle (roughly the deep anterior and inferior quarter) attach to the gluteal tuberosity of the femur.

The ischial tuberosity can be felt on deep palpation through the inferior part of the muscle, just superior to the medial part of the gluteal fold. When the thigh is flexed, the inferior border of the gluteus maximus moves superiorly, leaving the ischial tuberosity subcutaneous. You do not sit on your gluteus maximus; you sit on the fatty fibrous tissue and the ischial bursa that lie between the ischial tuberosity and skin.

The gluteus maximus also has associations with three bursae: the trochanteric, ischial, and gluteofemoral bursae. The trochanteric bursa separates the gluteus maximus from the greater trochanter, the ischial bursa separates the gluteus maximus from the ischial tuberosity, and the gluteofemoral bursa separates the iliotibial tract from the vastus lateralis.

The inferior gluteal nerve and vessels enter the deep surface of the gluteus maximus at its center. It is supplied by both the inferior and superior gluteal arteries. In the superior part of its course, the sciatic nerve passes deep to the gluteus maximus.

The main actions of the gluteus maximus are extension and lateral rotation of the thigh. When the distal attachment of the gluteus maximus is fixed, the muscle extends the trunk on the lower limb. Although it is the strongest extensor of the hip, it acts mostly when force is necessary (rapid movement or movement against resistance). The gluteus maximus functions primarily between the flexed and standing (straight) positions of the thigh, as when rising from the sitting position, straightening from the bending position, walking uphill and upstairs, and running. It is used only briefly during casual walking and usually not at all when standing motionless.

Because the iliotibial tract crosses the knee and attaches to the anterolateral tubercle of the tibia (Gerdy), the gluteus maximus and tensor fasciae latae together are also able to assist in making the extended knee stable, but they are not usually called on to do so during normal standing. Because the iliotibial tract attaches to the femur via the lateral intermuscular septum, it does not have the freedom necessary to produce motion at the knee.

Clinically

Paralysis of the gluteus maximus does not seriously affect walking on level ground. Verify this by placing your hand on your buttocks when walking slowly. The gluteus maximus contracts only briefly during the earliest part of the stance phase (from heel strike to when the foot is flat on the ground, to resist further flexion as weight is assumed by the partially flexed limb). If you climb stairs and put your hands on your buttocks, you will feel the gluteus maximus contract strongly.

See Also: Gluteal Tendinopathy

Testing the gluteus maximus is performed when the person is prone with the lower limb straight. The person tightens the buttocks and extends the hip joint as the examiner observes and palpates the gluteus maximus.

References & More

1. Cael, C. (2010). Functional anatomy: Musculoskeletal anatomy, kinesiology, and palpation for manual therapists. Philadelphia, PA: Wolters Kluwer Health/Lippincott, Williams & Wilkins.
2. Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Philadelphia, PA: Lippincott Williams & Wilkins.
3. Clinically Oriented Anatomy – 8th Edition
4. Elzanie A, Borger J. Anatomy, Bony Pelvis and Lower Limb, Gluteus Maximus Muscle. [Updated 2023 Apr 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: Pubmed