What ligament acts as the primary support for the sternoclavicular joint?

The costoclavicular ligament serves as the primary support for the sternoclavicular joint by anchoring the clavicle to the first rib. This ligament plays a crucial role in stabilizing the sternoclavicular joint during arm movements and helps prevent excessive upward or anterior displacement of the clavicle. Its positioning allows it to effectively manage the forces acting on the joint, providing essential support to maintain proper alignment and function.

Understanding the role of the costoclavicular ligament highlights the importance of the anatomical relationships within the shoulder girdle, which contribute to a wide range of motions while ensuring stability. Other ligaments mentioned do not provide the same level of direct support to the sternoclavicular joint, as their roles are focused on different aspects of shoulder stability and motion.