The pelvis forms the base of the spine as well as the socket of the hip joint. The pelvic bones include the hip bones, sacrum, and coccyx.
The hip bones are composed ofthree sets of bones that fuse together as we grow older. Each set is nearly symmetrical across the body’s midline. The parts of the hip bone are:
The sacrum is a triangular bone wedged into the rear section of the pelvis. It is made up of five fused vertebral bones. The female sacrum is shorter and wider than a male’s. The sacrum is connected to the tailbone, or coccyx, which is made of several fused vertebral bones at the base of the spine.
The female pelvic bones are typically larger and broader than a male’s. This is so a baby can pass through the pubic outlet, the circular hole in the middle of the pelvic bones, during childbirth. The pubic arch, or space under the base of the pelvis, is also wider for this reason. A man’s pelvis is typically narrower and smaller than a woman’s because they needed to be quick runners during man’s hunter-gatherer period of history.
The opening at the base of the pelvis, the obturator foramen, creates the ball-and-socket hip joint with the femur, the large bone of the leg. This joint and its ability to rotate in many angles is one of many pieces of anatomy that allows humans to walk.
The spine, or vertebral column, is a tower of bone that consists of 24 irregular-shaped bones along with the nine fused bones in the sacrum and coccyx. The spine gives human beings their posture as well as houses and protects the spinal column, the body’s major nerve center.