Stand up straight with your affected arm held in front of you at shoulder height.
Turn your palm to face the floor, and then drop your wrist so that your hand flops.
Next, bring your forearm up towards the side of your head, bending your elbow.
Allow your forearm to rotate back as far as it can go while simultaneously extending your wrist backwards.
When you begin to feel a stretch, return your arm to the starting position, and then repeat the sequence.
The exercise should flow as one continual movement.