Pelvic tilts

Lie on a bench or the floor with your feet pointed straight over your hips.  Lift your butt only 2-3 inches from the bench and tilt your pelvis upwards.  This should isolate your lower abdominals, important to balance out the lower back.  If you have lower back pain, you should do this exercise.  If your back hurts while you do this one, keep your feet on the surface and practice tilting your pelvis and tightening the lower abdominals.