The pelvis is a basin-shaped structure that supports the spinal column and protects the abdominal organs. It contains the following:
Sacrum. A spade-shaped bone that is formed by the fusion of 5 originally separate sacral vertebrae.
Coccyx (also called the tail bone). Formed by the fusion of 4 originally separated coccygeal bones.
Three innominate bones. These include the following:
Ilium. The broad, flaring portion of the hip bone (the crest of the pelvis).
Pubis. The lower, posterior part of the hip bone.
Ischium. One of the bones that helps form the hip.