The hip bone, also known as the pelvis, is a large, bony structure located at the base of the spine. It connects the trunk to the lower limbs and supports the weight of the upper body when sitting and standing. The hip bone is made up of three parts: the ilium, ischium, and pubis, which fuse together in adulthood. The hip bone plays a crucial role in movement and stability. It forms the socket for the hip joint, where the femur (thigh bone) fits in, allowing for a wide range of motion. Additionally, the hip bone protects vital organs in the lower abdomen and supports the reproductive system.