Ischium
Os ischii
SkeletalSkeletonPelvisLeft and right
View left in 3D View right in 3D
- What it is
- The lower posterior part of the hip bone: a thick body behind the acetabulum, the ischial spine, the rough ischial tuberosity, and a flat ramus that joins the pubis around the obturator foramen.
- Function
- Bears the body weight when sitting and anchors the hamstrings and adductor magnus.
- Size
- Tuberosity ≈ 5 cm long; inter-tuberous distance ≈ 11 cm
- Clinical note
- The ischial spines mark the narrowest part of the birth canal and guide pudendal nerve blocks.