In this edition of pete makes things more complicated, we will be testing external rotation at 90 degrees of abduction in both standing and prone/quadurped, in order to have the maximal load at either the top or bottom of the exercise. Depending on the person, we can have more weakness at either end range, as the change in neuromuscular demand due to sarcomere length becomes a factor.
Be very careful to look for the wrist flick at any part of the motion, the wrist extensors can try to give a little or a lot of extra momentum when the cuff stalls out