Step by step instructions
Sit on a Swiss ball, holding dumbbells. Round spine and walk feet out until mid-back is on the ball and shoulders and head are extended slightly over the top, with feet hip-width apart and under knees. Extend arms over midline of chest with palms facing away from head.
Reach left arm to ceiling, lifting head and left shoulder blade off the ball (keep both arms extended). Quickly repeat on opposite side to complete one rep.