Each circle rotates round the right hand of the striker, who should add support to it by turning the relevant shoulder towards the ball. This assists the eyes to focus on the ball and obviates using arm strength.
For the forehands on the offside and the backhands on the nearside, the left shoulder couples with the chin. The right shoulder takes over the task for the nearside forehands and the offside backhands. It can help if you think of the chin and shoulder fighting each other.