Gluteus maximus

Gluteus maximus is the largest and most superficial of the three gluteal muscles. It makes up a large portion of the shape and appearance of the buttocks. Its thick fleshy mass, in a quadrilateral shape, forms the prominence of the buttocks. Its large size is one of the most characteristic features of the muscular system in humans, connected as it is with the power of maintaining the trunk in the erect posture. Other primates have a much less developed gluteus maximus.

Anatomy

The gluteus maximus arises from the posterior gluteal line of the inner upper ilium, and the rough portion of bone including the crest, immediately above and behind it; from the posterior surface of the lower part of the sacrum and the side of the coccyx; from the aponeurosis of the erector spinae (lumbodorsal fascia), the sacrotuberous ligament, and the fascia covering the gluteus medius.

Function

The gluteus maximus is involved in a number of actions, including extension and external rotation of the hip joint, and adduction and abduction of the hip (outward and inward movement). It is also one of the chief muscles for hip extension when the thigh is flexed at the hip, such as in climbing stairs or rising from a sitting position.

Clinical significance

Injury or strain to the gluteus maximus can cause pain and difficulty with movement. It can also be involved in conditions such as piriformis syndrome, in which the piriformis muscle irritates the sciatic nerve, causing pain in the buttocks and referring pain along the course of the sciatic nerve.

See also

• Gluteal muscles
• Hip joint
• Piriformis syndrome

References

• 
  Gluteus maximus
• 
  Gluteus maximus
• 
  Gluteus maximus
• 
  Gluteus maximus
• 
  Gluteus maximus
• 
  Gluteus maximus
• 
  Gluteus maximus
• 
  Gluteus maximus
• 
  Gluteus maximus
• 
  Gluteus maximus
• 
  Gluteus maximus
• 
  Gluteus maximus