ABSTRACT
As the pelvic girdle is barely flexible, movement of the lower limb is largely at the hip joint, which also transmits the body weight. When compared with the shoulder, the synovial ball and socket hip has increased stability but reduced mobility. The head of the femur (1) lies within the deep socket of the acetabulum (2); itself deepened by the fibrocartilage labrum (3). The femoral head is offset from the femoral shaft (4) by the femoral neck (5), which means all hip movements become rotation of the head within the acetabulum.
