Sacrum, pelvic surface
Image of a male pelvis (sacrum is in center)
|Anatomical terms of bone|
It fits like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx (tailbone). During the first half of life these bones gradually fuse together.
The sacrum is concave facing forward, and tilted forward. The sacrum connects with four bones: