the most narrow part of the femoral neck, is covered by the other ligaments which partly radiate into it. The zona orbicularis acts like a buttonhole on the femoral head and assists in maintaining the contact in the joint.All three ligaments become taut when the joint is extended - this stabilises the joint, and reduces the energy demand of muscles when standing.

The intracapsular ligament, the ligamentum teres, is attached to a depression in