The pelvis is the part of the body located between the abdomen and the thighs. The term 'pelvis' can refer to the pelvic skeleton (also known as the pelvic girdle), which is the skeleton embedded in the lower part of the trunk, connecting the axial skeleton to the lower extremities.
The pelvic skeleton is composed of the following bones:
- Pair of hip bones, each of which consists of three bones - the ilium, ischium, and pubis
There are four joints between the bones of the pelvis:
- Sacroiliac joints (2) - articulations between the ilium of the hip bones, and the sacrum
- Sacrococcygeal symphysis - between the sacrum and the coccyx
- Pubic symphysis - between both bodies of the pubis in the anterior midline
Several ligaments extend between the lateral borders of the sacrum to various bony landmarks on the pelvis, aiding stability to the pelvis.
The pelvic skeleton is strong and rigid, adapted to serve several roles in the human body, including:
- Transferring weight from the upper axial skeleton to the lower extremities, especially during motion;
- Providing attachment for many muscles and ligaments used in locomotion;
- Enclosing and protecting abdominopelvic and pelvic viscera;
- Providing natural childbirth, when the neonate passes through the birth canal which lies in the pelvic girdle.