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Gluteus maximus muscle

The gluteus maximus is the largest and most superficial of the three gluteal muscles, forming the bulk and contour of the buttock. It is a broad, thick, quadrilateral muscle that arises from multiple sites: the posterior gluteal line of the ilium, dorsal surface of the sacrum and coccyx, and the sacrotuberous ligament. It inserts into two major areas: the iliotibial tract (IT band), which continues to the lateral condyle of the tibia, and the gluteal tuberosity of the femur.

The gluteus maximus is the primary extensor of the hip joint, especially active during powerful lower-limb movements such as rising from sitting, climbing stairs, and running. It also contributes to external rotation and abduction of the hip, and plays a vital role in stabilizing the pelvis and trunk during locomotion.

Clinically, the gluteus maximus is important in hip replacement surgery, intramuscular injections, musculoskeletal trauma, and sports injuries. Weakness or injury to this muscle contributes to gait abnormalities such as difficulty rising or climbing.

Synonyms

  • Great gluteal muscle

  • Musculus gluteus maximus

  • Largest hip extensor

Function

  • Extends the thigh at the hip joint (especially from a flexed position)

  • Externally rotates and abducts the hip

  • Stabilizes the sacroiliac joint, pelvis, and trunk during movement

  • Provides propulsion in running, jumping, and climbing

Nerve Supply

  • Inferior gluteal nerve (L5, S1, S2)

Arterial Supply

  • Inferior gluteal artery (primary supply)

  • Contributions from superior gluteal artery and medial circumflex femoral artery

Venous Drainage

  • Inferior gluteal vein → internal iliac vein

  • Anastomoses with superior gluteal vein and femoral vein tributaries

MRI Appearance

T1-weighted images:

  • Normal gluteus maximus muscle shows intermediate signal intensity with well-defined fascicular pattern

  • Fat planes between muscle bundles appear hyperintense

T2-weighted images:

  • Normal muscle: intermediate to low signal

  • Pathology (strain, tear, myositis) appears as hyperintense signal within muscle fibers

STIR:

  • Suppresses fat signal, highlighting muscle edema, contusion, or inflammation as bright hyperintense regions

  • Very sensitive for detecting acute muscle injury

T1 Fat-Saturated (Pre-contrast):

  • Muscle fibers appear intermediate signal against suppressed fat

  • Useful for distinguishing muscle from surrounding adipose tissue

T1 Fat-Saturated Post-Contrast (Gadolinium):

  • Normal gluteus maximus enhances mildly and uniformly

  • Pathological processes such as abscess, tumor, or myositis enhance heterogeneously

  • Enhancement around tear margins highlights muscle injury or scar tissue

MRI Non-Contrast 3D Imaging:

  • Provides volumetric detail of gluteus maximus size, attachments, and relationship to pelvis and femur

  • Useful for preoperative planning in reconstructive and oncologic surgery

CT Appearance

CT Pre-Contrast:

  • Gluteus maximus appears as a homogeneous soft-tissue density in the posterior hip region

  • Useful for identifying atrophy, calcification, or hematomas

CT Post-Contrast:

  • Normal muscle enhances moderately and homogeneously

  • Highlights traumatic tears, tumors, abscesses, and inflammatory changes

  • 3D reconstructions assist in orthopedic and reconstructive surgical planning

MRI images

Gluteus maximus muscle MRI coronal image anatomy image -img-00000-00000

MRI images

Gluteus maximus muscle MRI coronal image anatomy image -img-00000-00000_00001

MRI images

Gluteus maximus muscle MRI coronal image anatomy image -img-00000-00000_00002

CT images

Gluteus maximus muscle CT axial image 1

CT images

Gluteus maximus muscle CT axial image 3

CT images

Gluteus maximus muscle CT axial image