Start in a kneeling position with a stability ball placed in front of you.
Place your forearms on the stability ball.
Drop your hips forwards until you have a straight line from your head to your knees.
Maintain good strength in your shoulders.
Lift your knees off the floor so that you now have a straight line from your heels to the top of your head.
Hold this position and roll the ball in two clockwise circles and then reverse direction and perform two anticlockwise circles.
Continue on in a fluid controlled movement for the required duration.