Gluteus Maximus

1. Overview

The gluteus maximus is the largest and most superficial of the three gluteal muscles. It forms the bulk of the buttock and is one of the strongest muscles in the human body. This powerful extensor of the hip joint plays a central role in maintaining posture, locomotion, and explosive movements such as running, jumping, and climbing. It also contributes significantly to the shape and contour of the posterior pelvis.

2. Location

The gluteus maximus is located in the posterior region of the pelvis:

• Superficially: Lies directly under the skin and subcutaneous tissue of the buttock.

• Medially: Originates near the sacrum and coccyx.

• Laterally and inferiorly: Inserts into the iliotibial tract and gluteal tuberosity of the femur.

• Adjacent structures: Covers the deeper gluteus medius and minimus muscles, sciatic nerve, and other posterior hip muscles.

3. Structure

The gluteus maximus is a thick, quadrilateral muscle with a broad origin and a narrow insertion:

• Origin:

  • Posterior iliac crest

  • Dorsal surface of the sacrum and coccyx

  • Sacrotuberous ligament

  • Thoracolumbar fascia

• Insertion:

  • Gluteal tuberosity of the femur

  • Iliotibial (IT) tract, which continues to the lateral condyle of the tibia

• Innervation: Inferior gluteal nerve (L5, S1, S2)

• Blood supply: Primarily from the superior and inferior gluteal arteries

4. Function

The gluteus maximus is primarily responsible for extension of the hip joint, but it also contributes to other movements:

• Hip extension: Especially during forceful movements like climbing stairs or rising from a seated position.

• External (lateral) rotation of the hip: Rotates the thigh outward.

• Abduction of the hip: The upper fibers assist in moving the thigh away from the midline.

• Stabilization: Helps stabilize the pelvis and the knee (via the IT band) during locomotion.

5. Physiological role(s)

Beyond mechanical movement, the gluteus maximus plays key physiological roles:

• Postural support: Maintains upright posture by resisting hip flexion during standing and walking.

• Energy storage: Assists in elastic recoil during gait by storing energy in the fascia and tendons.

• Pelvic alignment: Maintains the alignment of the pelvis and lumbar spine during dynamic movement.

• Thermal regulation and protection: Due to its size and superficial position, it insulates and cushions underlying structures, including the sciatic nerve.

6. Clinical Significance

The gluteus maximus is involved in various clinical conditions and is important in rehabilitation and sports medicine:

• Gluteal strain or tear:

  • Common in athletes, especially sprinters and jumpers, leading to pain and weakness in hip extension.

• Gluteal atrophy:

  • Can result from disuse, nerve injury, or prolonged immobilization; associated with lower back pain and gait abnormalities.

• Inferior gluteal nerve injury:

  • Causes weakness in hip extension, difficulty climbing stairs or rising from a chair.

• Trochanteric bursitis:

  • May be aggravated by overuse or weakness of the gluteus maximus, leading to lateral hip pain.

• Sciatic nerve compression:

  • Hypertrophy or tightness of the gluteal muscles can irritate the underlying sciatic nerve.

• Rehabilitation focus:

  • Gluteus maximus strengthening is a key component in programs for lower back pain, knee injuries, and hip dysfunctions.