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Bone: Ischium of pelvis
Pelvic girdle
Left hip-joint, opened by removing the floor of the acetabulum from within the pelvis. (Ischium labeled at bottom left.)
Latin	os ischii
Gray's	subject #57 234
MeSH	Ischium

The ischium forms the lower and back part of the hip bone (os coxae). The word comes from the Greek ischion, meaning "hip." (Taber's, 1985).

Situated below the ilium and behind the pubis, it is one of these three bones whose fusion creates the coxa.

It is divisible into three portions:

• Body of ischium - the portion that supports weight while sitting (especially noticeable on a hard surface).
• Superior ramus of the ischium
• Inferior ramus of the ischium

It is the strongest of the coxal bones.

Clinically, avulsion fracture of the ischial apophysis may occur.

[edit] Additional images

Right hip bone. External surface.	Right hip bone. Internal surface.	Plan of ossification of the hip bone.	Male pelvis.
The Obturator externus.	Pelvis

[edit] External links

• SUNY Labs 44:st-0722 - "The Male Pelvis: Hip Bone"
• ischium at eMedicine Dictionary
• Cross section at UV pelvis/pelvis-e12-15

[edit] References

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.

This musculoskeletal system article is a stub. You can help Wikipedia by expanding it. v • d • e

v • d • e Bones of pelvis / pelvic cavity (TA A02.5.01-03, GA 2.231-241) General sacrum · coccyx · hip bone Ilium body arcuate line wing gluteal lines (posterior, anterior, inferior) iliac spines (anterior superior, anterior inferior, posterior superior, posterior inferior) other: crest · tuberosity · fossa Ischium body ischial spine · lesser sciatic notch superior ramus tuberosity of the ischium inferior ramus no substructures Pubis body pubic crest superior ramus pubic tubercle · obturator crest inferior ramus pectineal line Compound acetabulum (acetabular notch) · iliopubic eminence / iliopectineal line · linea terminalis · ischiopubic ramus / pubic arch obturator foramen · greater sciatic foramen / greater sciatic notch · lesser sciatic foramen lesser pelvis (pelvic inlet, pelvic brim, pelvic outlet) · greater pelvis