Glenoid line is drawn between superior (s) and inferior (i) ridges, clavicular line is drawn between conoid tubercle (c) and the AC joint (j), the angle (g) between the humeral line (h) and the glenoid line (si) represents the GH elevation angle, the angle (e) between the humeral line (h) and the vertical line (v) represents the arm elevation angle, and the angle (a) between the glenoid and clavicular lines minus 90 degrees indicates the AC rotation angle.