Stand up straight sideways to a wall.
Your affected side should be closest to the wall.
Bend your elbow.
Press the outside of your forearm into the wall, ensuring the movement comes from your shoulder and not your wrist.
Imagine you are trying to rotate your forearm outwards.
The pressure on the wall should be on your forearm just above your wrist.
Hold this position, with your gaze directly ahead, your neck long and your shoulder blades back and down.