Start on your knees with your back towards a wall and place your feet so that they are flat against it. Position a stability ball in front of you touching your thighs. Lean forward on the ball, straighten your legs and dig your heels into the wall behind you. Place your hands on your head and extend your body into a straight line from head to toe. Lower your upper body down from the hips and return back to your straightened position by squeezing your glutes.