1.1.3 Movements of the clavicle and scapula
Now let's see how the clavicle and the scapula move, relative to the trunk. Upward movement of the scapula is called elevation; downward movement is called depression. Forward movement around the trunk is called protraction; the opposite movement is retraction. This movement is called upward rotation. The opposite movement is downward rotation. In real life these movements of the scapula are often combined.
The range of motion of the scapula provides fully one third of the total range of motion of the humerus, relative to the body, sometimes more. Without this movement of the scapula, we'd only be able to abduct our arm to here. That's as far as the shoulder joint goes, before bone hits bone. It's scapular movement that lets us get all the way to here.