Secure an exercise band slightly above the floor level.
Lie on your back with knees bent. Hold an exercise band with your arm out to the side, supported on a folded towel. The arm is externally rotated, the elbow bent and palm facing towards the ceiling. Put the opposite hand on the top of the shoulder to support movement awareness.
Keeping elbow in place, rotate your arm inwards and bring your hand towards the floor. In a controlled manner return to the starting position.