The lower limb is specialized for supporting the body's weight and locomotion, the ability to move from one place to another and maintain balance, the condition of being evenly balanced. The lower limbs are connected to the trunk by the lower limb girdle (hip bones and sacrum).

The skeleton of the lower limb is formed by the two bones of the hip, joined at the pubic symphysis and the sacrum. The lower limb cingulate and sacrum together form the BONE PELVIS .

The Iliac is a flat, flat, irregular, paired bone made up of the fusion of three bones:

  • Ilium – upper 2/3
  • Ischium – lower and posterior 1/3 (stronger)
  • Pubis – lower and anterior 1/3

The bone has two faces, four edges and four angles.


Outer Face

  • Iliac wing – posterior gluteal line, anterior gluteal line, and inferior gluteal line
  • Acetabular cavity – large joint cavity formed by the union of the three hip bones: ilium, ischium and pubis. The acetabulum has the following structures: semilunar surface, acetabulum fossa and acetabulum notch
  • Thorium obturator foramen – large rounded opening located between the ischium and pubis

Inner face

  • Iliac fossa – large, smooth and concave face
  • Ear Face
  • Line Arcuate – divides the ilium into body and wing


Top Edge

  • Iliac crest – divided into: outer and inner lip and an intermediate line

Front Edge

  • Anterosuperior Iliac Spine
  • Anteroinferior Iliac Spine
  • Iliopectineal Eminence – the point where the ilium meets the pubis

Back Edge

  • Posterosuperior Iliac Spine
  • Posteroinferior Iliac Spine
  • Greater Sciatic Notch – superior to the ischial spine
  • Sciatic Spine – thin, pointed triangular eminence
  • Lesser Sciatic Notch – inferior to the ischial spine
  • Ischial tubercle – large, dilated bump

Bottom Edge

  • Ischiopubic branch – union of the ischium with the pubis


  • Anterosuperior: Anterosuperior iliac spine
  • Posterosuperior: Posterosuperior iliac spine
  • Posterior Inferior: Sciatic tubercle
  • Anteroinferior: Pubis

The Iliac articulates with three bones: Sacrum, Femur and the Iliac on the opposite side.

Articulação do Osso do Quadril



Ilíaco - Vista Lateral

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.


Ilíaco - Vista Medial

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.

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