Lie on your back on the floor with your knees bent and feet flat on the floor. Exhale and draw your navel into your spine, pushing your low back to the floor. Continue pulling in the abs to see how far you can tilt the bottom of your pelvis up. You will feel your low back gently stretching and reaching in the direction of the floor. To gauge how much pressure you are exerting, slide your hand between your low back and the floor and then press your low back against your hand. Then allow the spine and pelvis to return to their original position.