The arcuate line of the ilium is a smooth rounded border on the internal surface of the ilium. It is immediately inferior to the

iliac fossa The iliac fossa is a large, smooth, concave surface on the internal surface of the ilium (part of the three fused bones making the hip bone). Structure The iliac fossa is bounded above by the iliac crest, and below by the arcuate line. It is b ...

and

Iliacus The iliacus is a flat, triangular muscle which fills the iliac fossa. It forms the lateral portion of iliopsoas, providing flexion of the thigh and lower limb at the acetabulofemoral joint. Structure The iliacus arises from the iliac fossa on ...

muscle. It forms part of the border of the

pelvic inlet The pelvic inlet or superior aperture of the pelvis is a planar surface which defines the boundary between the pelvic cavity and the abdominal cavity (or, according to some authors, between two parts of the pelvic cavity, called lesser pelvis an ...

. In combination with the pectineal line, it comprises the

iliopectineal line The iliopectineal line is the border of the iliopubic eminence. It can be defined as a compound structure of the arcuate line (from the ilium) and pectineal line (from the pubis). With the sacral promontory, it makes up the linea terminalis The ...

. The arcuate line marks the border between the body (''corpus'') and the

wing A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is e ...

(''ala'') of the ilium, and, running inferior, anterior, and medial from the auricular surface to the area corresponding to the

acetabulum The acetabulum (), also called the cotyloid cavity, is a concave surface of the pelvis. The head of the femur meets with the pelvis at the acetabulum, forming the hip joint. Structure There are three bones of the ''os coxae'' (hip bone) that c ...

, it also indicates where weight is transferred from the

sacroiliac joint The sacroiliac joint or SI joint (SIJ) is the joint between the sacrum and the ilium bones of the pelvis, which are connected by strong ligaments. In humans, the sacrum supports the spine and is supported in turn by an ilium on each side. T ...

to the

hip joint In vertebrate anatomy, hip (or "coxa"Latin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) in medical terminology) refers to either an anatomical region or a joint. The hip region is ...

Additional images

Arcuate line of ilium 02 animation.gif, Position of arcuate line of ilium. Shown in red. Arcuate line of ilium 03 animation.gif, Close up. Skeletal pelvis-pubis.svg, Pelvis with the iliopectineal line indicated in red.

References

External links

* {{Authority control Bones of the pelvis Ilium (bone)