Take position on the ground with one hand on the top of a medicine ball and the other hand just outside shoulder-width apart. On both hands, fingers are facing forward. The non-ball arm is outstretched until the elbow joint is totally opened lifting the torso up. The ball-arm will have a necessary slight bend at the elbow. You should be up on your toes but with your legs spread wider if necessary to support the movement. Your body should be flat, not arched either way. This is the starting position.
Lower your torso down as you inhale, keeping the elbows close by the body not flaring them outward. Your chest should approach but the floor but not quite touch with the available range of motion due to one hand being on the ball.
Squeeze your chest and exhale as you reverse the movement back to the starting position. Change sides.