Protraction is anterior movement of the lateral end of the clavicle. For this movement-the medial end of the clavicle is concave and the manubrium is convex. The medial clavicle moves in the same direction as the lateral clavicle. As the scapula protracts, the clavicle protracts. Protraction is checked by the costoclavicular ligament and the anterior SC ligament.
Retraction is checked by the costoclavicular and posterior SC ligament.
Spin of the clavicular head on the manubrium. This can be produced by tension of the conoid part of coracoclavicular ligament on the clavicle. During elevation of the arm, posterior clavicular rotation occurs. The inferior surface will face anterior following the rotation. Because of the antero-lateral convexity of the clavicle, when rotation occurs, the lateral end of the clavicle moves superiorly.