Slide show: Practice healthy posture and give your back a break

When it comes to posture, your mother did know best. Her frequent reminders to "stand up straight" and "stop slouching" were good advice.

Your spine is strong and stable when you practice healthy posture. But when you stoop or slouch, your body's center of gravity shifts. Your muscles and ligaments struggle to keep you balanced. This can lead to painful strains and sprains of ligaments and muscles in your back. It can also cause neck pain, joint stiffness, fatigue and other health problems.

If you have chronic backaches, healthy posture will help relax your back muscles and may reduce your pain. Practicing good posture may also prevent backaches and other problems.

A healthy back has three natural curves: an inward or forward curve at the neck (cervical curve), an outward or backward curve at the upper back (thoracic curve), and an inward curve at the lower back (lumbar curve). Good posture doesn't mean balancing a book on your head or standing at military-style attention. It simply aims to maintain these natural curves. In contrast, poor posture actually leads to changes in natural spinal curves, which can stress or pull muscles and cause pain.

When standing, keep your chest held high and your shoulders back and relaxed. Try not to tilt your head forward, backward or sideways. Instead, tuck your chin down slightly and pull your head back and up as if to flatten your neck against a wall.

Pull in your abdomen and buttocks. Make sure your knees are relaxed, not locked. Keep your feet parallel and your weight balanced evenly on both feet.

To test your standing posture, take the wall test. Stand with your head, shoulder blades and buttocks touching a wall, with your heels about two to four inches away from the wall. Reach back and slide your hand behind the curve in your lower back, with your palm flat against the wall.

There should be about one hand's thickness of space between your back and the wall. If there's too much space, tighten your abdominal muscles to flatten the curve in your back. If there's too little space, arch your back so that your hand fits comfortably behind you. Walk away from the wall while maintaining this posture. Then return to the wall to check your success. Practice maintaining healthy posture during your daily activities.

Good sitting posture keeps your neck, shoulders and upper back muscles relaxed. Choose a chair that allows you to rest both feet flat on the floor, while keeping your knees level with your hips. If this doesn't feel comfortable, try placing a foot support under your feet to find the best position for you.

Stretch the top of your head toward the ceiling. Tuck your chin in slightly. Keep your upper back and neck comfortably straight. Keep your shoulders relaxed, not elevated, rounded or pulled backward. Sit with your back firmly against the chair. Place a small cushion or rolled towel to support your lower back curve if your chair doesn't provide the support you need.

Pay attention to the position of your shoulders when you're sitting or standing. Slouching or rolling your shoulders forward shortens your chest muscles and reduces their flexibility (kyphosis). But, if you pull your shoulders too far back, you can develop swayback (lordosis), in which your abdomen sticks out too far in front and your buttocks stick out too far in back.

Stand in front of a mirror to see if you're keeping your shoulders straight, or ask a friend to evaluate your shoulder position. Your shoulders should be in the same position as the picture on the left. You may find that this is difficult for you, especially if you work at a computer or sit for long periods to read.

Although good posture should be natural, you may feel wooden or stiff at first if you've forgotten what good posture feels like. The key is to practice good posture all the time. You can make improvements at any age. Stretching and core strengthening exercises may help because they strengthen the lower abdominal muscles that support your spine. Talk with your doctor if you're concerned about your posture or if you need help deciding if certain exercises are right for you.