Finger movement at birth in brachial plexus birth palsy

Figure 1 Schematic drawing showing the method of calculating glenoid version and percentage of humeral head anterior to scapular line. Measuring the glenoid version angle (theta;): The scapular line is drawn between the medial margin of the scapula to the midpoint of the glenoid. Another line is drawn through the anterior and posterior aspects of the glenoid labrum. The angle between these two lines is measured, and 90° is subtracted. A negative value indicates a retroverted glenoid. A line perpendicular to the scapular line is drawn and the percentage of humeral head anterior to scapular line is defined as the ratio of the distance from the scapular line to the anterior portion of the head to the diameter of the humeral head (LM/LN × 100). Reproduced from Nath RK et al[7].