Stand with your legs hips-width apart and hold your affected arm out to the side and in front a little.
This position is called scaption.
Turn your arm so your thumb points downwards.
Lower your arm back down by your side, keeping the thumb pointing down, then lift the arm back up.
Continue this movement, pulsing the arm, making sure you keep your shoulders relaxed and your neck long.
Turn your palm so that your thumb points upwards, and repeat the movement.
