Sit or stand up straight with your affected arm out to your side and your elbow bent.
Your palm should face the side of you head.
Place your other hand across your shoulder and collar bone, applying some gentle downwards pressure to keep your neck long.
Move your hand and forearm in towards the side of your head, touching your fingertips to your throat.
Bring your forearm back to the vertical position and repeat as one fluid movement, ensuring you do not over stretch.