This part of the body is made of the sacrum and the two pelvic bones which are joined to it on either side. The pelvic bones are carried by the leg bones, and they support the "spinal column". Each pelvic bone has a strong structure for the leg bone to fit into, so that a person can stand, walk, run and jump. Each pelvic bone spreads into a large flat plate which supports the person's "internal organs". The pelvis of a woman spreads into a wider shape than a man's, so that when the woman is pregnant, the baby is supported by the pelvis, until it is ready to be born. At the bottom of the pelvis is a large opening, big enough for a baby to pass through.