What Is the Hip?

The hip is defined as the region on each side of the pelvis. The hip bone is made up of three sections, including 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.
• Hip joint - The ball-and-socket joint that allows motion and provides stability needed to bear body weight.

The socket area, which is inside the pelvis, is called the acetabulum. The ball part of this joint is the top of the leg bone. It joins with the acetabulum to form the hip joint.

The hip is one of the most stable joints in the body. But, its function, bearing the body's weight, makes it susceptible to arthritis due to excessive pressure. Pain in the hip may involve injury to muscles, tendons, or bursae (small fluid-filled sacs that cushion and lubricate joints).