Also: Ask Dr. Tedd Mitchell a health question

Your aching back

Remember the 3 R's: Respect your back, resist awkward positions, and restore good posture.

I am a sports medicine physician, so my patients regularly discuss back pain with me. In fact, lower back pain is the second most common reason people go to a doctor, surpassed only by colds and flu.

The lower back is particularly at risk because it's built on a curve and supports most of the body's weight. Our spine is responsible not only for carrying our body weight in an upright position, but also for protecting the spinal cord, which controls all of the body's nerves.

The back is a complex system of muscles, tendons, ligaments and bones. The various puzzle pieces fit together in a series of "pulleys" up and down the spine, allowing for mobility. The system also protects the spinal canal, which stabilizes the strength of the body's large muscle groups. With such an intricate system, it's not surprising that pain occurs when parts of the system go awry.

Luckily, exercising some back-friendly habits can keep your spine healthy. Follow the three R's:

Respect your back. The back helps support your weight when lying down, sitting up or standing. Accordingly, when lying down, make sure your mattress is supportive and evenly distributes your body weight. An old mattress is a common cause of back pain. When sitting, choose chairs that support the lumbar spine, or lower back; this helps to keep it properly aligned. Finally, when standing, wear supportive shoes. This is particularly important for women, because high heels can be a recipe for chronic lower back pain.

Resist awkward positions. Many who hurt their backs do so when performing tasks in an "unfriendly" manner. Some pointers: Don't try to lift things while your back is twisted. And don't lean forward and lift an object using your back. Instead, squat down, get a solid grip, and put the weight into your legs when lifting the object.

Restore good posture. Implementing a consistent exercise program not only helps you stand up straight and stay fit, but it also prevents weight gain and backaches. A lack of exercise and being overweight are risks for developing back pain. If you're starting an exercise program, select low-impact activities. (Avoid high-impact exercises, like jogging, which "pound" the spine.) Specific strengthening exercises also are available to improve the muscles supporting the spine. If possible, have a qualified personal trainer evaluate your program.

Back pain is common, and prevention is key. Follow the three R's, and remember that a little attention to detail goes a long way when it comes to good back health. Contributing Editor Tedd Mitchell, M.D., is medical director of the Wellness Program at Dallas' Cooper Clinic.

Call your doctor if back pain occurs with any of these:

After trauma, such as a fall
Pain that radiates, especially down the backs of the legs
Muscular weakness in the hips or legs
Fever
Burning while urinating
Swelling, tenderness or redness in the back
Loss of bowel or bladder control (call 911 for this)