If you have back pain, you probably know your posture isn't good. If you sit for much of your waking day, you're training your body to be slumped over into folded, or "weak," posture. However, even though you may never be perfectly straight, there are ways to relieve your pain by strengthening your posture.

Low-back pain from sitting is a result of mechanical stress on the body. This is called poor biomechanics. When the body is not mechanically well aligned, posture, and therefore balance, is weak. When you stand up with weak posture, the simple act of balancing will overwork some muscles and cause stress on joints. The key to reducing this strain is to improve balance and the ability to control how you balance, and to retrain muscles and nerves for less pain and better function.

Step one toward stronger posture is improving the symmetry of how your body moves on each side. In fact, just changing the position from which you move can help free up locked and stiff joints, resulting in stronger posture and less pain.

--The Sitting Leg-Cross Stretch (below) is an easy back and hip stretch you can do at your desk. You can use your office chair or, if you want to challenge yourself, do the stretch while sitting on an exercise ball.

Steven Weiniger, DC, is the author of Stand Taller--Live Longer: An Anti-Aging Strategy. He created the StrongPosture exercise programs taught by certified posture exercise professionals, chiropractors, physical therapists, massage therapists, and other body professionals who promote the importance of posture. For more StrongPosture information, visit www.bodyzone.com.

Daily Posture Exercise
Sit tall and strong on the front edge of a chair or ball, as you cross your left leg over the right knee. Pull your belly in to brace your core. As you breathe out, keep your head and shoulders aligned as you pull your body forward. Take 2-3 breaths, and come up with your posture still strong. Repeat on the other side.