The pelvic girdle is adapted for stability. The bony pelvis functions to support and protect the abdominal and pelvic organs, as well as serve as attachment points for muscles of the abdomen and leg. It articulates with the femur. The femur is the largest bone in the body and provides support for the body during standing, walking and running. The ischium, one of the three bones that fuse to create the innominate, is especially large in Old World monkeys. The hip, like the shoulder is a ball-and-socket joint.