What is the ischium?
The the sit bone is called the ischium. Gray's Anatomy (1918) describes it as the lower and back part of the hip bone.
What it is
- The lower and back part of the hip bone.
- Its rough lower end (the ischial tuberosity) is the bone you sit on.
- One of the three parts that fuse to form the adult hip bone.
Where it is
- At the back and bottom of the hip bone.
- Below the ilium and behind the pubis.
- Contributes to the lower rim of the acetabulum.
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Last verified: 2026-07-18
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