The hip joint, medically known as the hip, is located in the lower part of the waist, the upper part of the lower limbs, and the two sides of the pelvis, and is the largest joint in the human body. In a broader sense, it consists of the hip bone and femur, including the femoral head, femoral neck, femoral ridge and femoral stem, which are surrounded by the joint capsule, ligaments, muscles and other soft tissues, forming the axis of movement of the human body. It is connected to the trunk and the lower extremities, supporting the human trunk and enabling the lower extremities to flex and straighten, abduct, adduct, internally rotate and externally rotate, thus enabling people to sit, squat, run, jump and other daily activities.