Shoulder posterior capsule stretch (Shoulder external rotators/posterior capsule stretch, arm forward 90/90, sitting)

Start in a seated position on a chair.
Place your affected arm upwards and in front of you on a high table or worktop.
Bend your elbow to a right angle with your fingers pointing up to the ceiling.
Place the hand of your other arm on the back of the wrist of your affected arm.
Push your affected forearm down towards the table using the wrist as a lever.
Do not allow your shoulders to hunch.
Hold this position.