What does the costoclavicular ligament limit during arm movements?

The costoclavicular ligament plays a key role in stabilizing the sternoclavicular joint, which connects the clavicle to the sternum. This ligament specifically limits the amount of elevation and assists in preventing excessive medial and lateral movements of the clavicle during arm movements. By controlling the position of the clavicle, the costoclavicular ligament helps ensure proper mechanics of the shoulder girdle and protects the surrounding structures during various upper limb activities.

In the context of the other options, they focus on different movements or joints that are not primarily influenced by the costoclavicular ligament. Flexion and extension generally pertain to movements at the shoulder and elbow joints. Protraction and retraction refer to movements of the scapula rather than the clavicle, and internal and external rotation primarily involve movements at the shoulder joint itself. Thus, the primary focus of the costoclavicular ligament is on stabilizing the clavicle and limiting elevation and medial/lateral motion, making the selected answer the most accurate.