that when you inhale, as your relax and push your belly forward, you get a noticeable tilt in your lower back also; when you exhale, you will straighten your lower back slightly.
             Second Stage: Now place your hands higher so you can feel your ribs. Your fingers should be barely touching. Inhale and expand the ribs, feeling that your fingers are pulled apart slightly. Now exhale and contract your ribs, noticing that the fingers are touching again. Combine these first two stages: as you inhale, relax and expand the ribs. As you exhale, contract your ribs and then tighten the stomach to push out the last of the air.
             ...