Sit or stand up straight and lift your affected arm out to the side.
Bend your elbow and rotate your forearm and hand so that your palm faces away from you.
With your other hand, stretch your wrist backwards and bring your palm in to rest against the side of your head.
Your forearm should face the ceiling, and your fingers should be pointing down towards the floor.
Ensure you do not over stretch.
Relax the stretch before gently repeating the movement.