Sit upright in a chair.
Place a folded towel between your upper arm and your body.
Squeeze your upper arm tightly against your body into the towel.
Ensure you keep your posture upright, with your shoulder blades relaxed throughout.
Maintaining this position, rotate your forearm outwards as far as you can manage comfortably.
Rotate your forearm back to the start position, ensuring you keep squeezing the towel throughout.
