The pelvis is not classified as a flat bone; instead, it is categorized as an irregular bone. Unlike flat bones, which are typically thin and serve protective roles (like the skull or ribs), irregular bones have complex shapes that do not fit into other categories.
The pelvis is a large bony structure that supports the spine and anchors the lower limbs. Its irregular shape is crucial for its role in bearing weight, and it provides a protective cage for the pelvic organs, such as the bladder and reproductive organs. The unique structure of the pelvis also allows for a range of movements, which is essential for walking, running, and other activities.