02-03: SELF ASSESS 90/90 SHOULDER EXTERNAL ROTATION SCREEN
Stand side onto a mirror, bend your elbow so it is 90-degrees to your upper arm and parallel to the floor.
Without bending your torso, or lifting your chest, rotate the arm backward, so it raises your hand towards vertical, as in image number 2.
Keep that 90-degree relationship between your upper arm and forearm.
STOP IF YOU FEEL PAIN at any time (and do not attempt The Fix exercise)
If the forearm angle does not equal the spine angel (as in image number 2) you may have limited external rotation.
Ideally your forearm angle is at least equal to your spine angle, or optimally greater than your spine angle, as in image number 3.