Figure 6: Rotational deformity of the affected scapula is represented by the difference between lines Z and Y (X - Vertebral column axis; AB - A line joining the center of the glenoid and the base of scapular spine to the vertebral column axis on the affected side; CD - A line joining the center of the glenoid and the base of scapular spine to the vertebral column on the normal side; Y - Angle between AB and X; Z - angle between CD and X)