Lean on top of an stability ball with the upper back on the ball and the hips out straight in front of the body, with knees bent at 90 degrees. Keep the body straight from shoulders to knees. Hold the arms out straight in front of the chest with the palms touching each other. Twist through the stomach and shoulders rotating on to one shoulder with the hips up. Keep the feet on the ground and back straight and rotate to the opposite side.