The two symmetrical hip bones are each made up of an ilium (the most superior or upper part of the pelvis), pubis (smallest hip bone) and ischium (the base of the pelvis). These are segmented in a fetus but fused in adults.
The pubis is also known as the pubic bone.
“Ilia” is the plural of “ilium.”
The hip bones are the largest and widest of the pelvic bones.
Palpate at the hips / waistline to feel the curved ridge of the ilium (called the iliac crest).
Sacrum
The triangular-shaped sacrum consists of 5 fused vertebrae.
It is kyphotic, curving away from body.
The sacrum is the base of the spine and the back of the pelvis.
Coccyx
Also known as the tailbone, the coccyx consists of 3 to 5 fused vertebrae.