SCIENCE / MEDICINE : Ouch! Back Pain Strikes 4 of 5 Americans : Prevention: Losing weight and exercising correctly can offer protection or minimize problems with your back. And Mom was right--good posture habits can also help.

Four out of every five adult Americans have experienced back pain--or eventually will encounter it. Men and women are equally vulnerable. Next to headaches, back pain is the most common complaint in this country.

It often strikes between the ages of 17 and 45, and can become a lifelong problem that worsens with age.

Back pain can have numerous causes. Examples include obesity, poor conditioning, damage from twisting or bending the back (gymnasts, nurses and truck drivers are at high risk), osteoporosis and various forms of arthritis.

Excess body weight can help cause or aggravate back pain by putting stress on the spine.

The standard way to lose weight is to eat less and exercise more. However, back pain can restrict the ability to exercise. As a result, controlling what is eaten becomes the key to losing weight.

Constipation frequently accompanies back pain. It may be a side effect of pain medications or the result of an inactive lifestyle.

A high-fiber diet can help. Fiber acts as a sponge in the digestive tract, bringing water into the intestines and softening the stool. Choose whole-grain starches, fruit with skin and seeds (such as apples, pears and raspberries) and fresh and slightly cooked vegetables.

Fiber can help prevent constipation if you drink plenty of water--about eight 8-ounce glasses a day.

Can you prevent back pain from occurring?

You can’t change your age, or whether you’ve had injuries in the past. But alterations in your lifestyle--including the way you perform movements of daily living--can offer protection or minimize the pain you feel.

PERFECTING YOUR POSTURE

Hand should fit snugly between and wall.

Head held erect with your chin tucked in.

Chest held high with shoulders and arms relaxed.

Stomach muscles held firm.

Knees straight but not locked.

Feet parallel.

GOOD HABITS FOR A BETTER BACK

Good posture includes an inward curve at the neck, an outward curve at the shoulders and an inward curve at the lower back. In the following activities, maintain these curves.

If you have back problems, ask your doctor if you need any special recommendations.

Lying down

From a seated position, lower your head and trunk, using arms for support. Raise your legs to the bed.

When lying on your side, bend your knees and place a pillow between them.

Option: Place a rolled-up towel under your waistline.

When lying flat on your back, bend your knees and support them with a pillow. Place a rolled-up towel in the small of your back.

Sitting

Select a chair that supports the small of your back--or use a cushion to fill the space.

Sit with feet flat on the floor and knees the same level as your hips. If necessary, use a stool to raise your feet. To get into a chair, move backward so that the backs of your legs touch the chair.

Stand with feet apart, one foot slightly forward.

Lower yourself to the edge of the chair, bending at the hips and knees. Then slide back slowly into the chair.

To get up, slide forward to the edge of the chair. With your chin tucked in slightly and one foot in front of the other, straighten your hips and knees to lift yourself gently from the chair.

Source: Mayo Clinic Nutrition Letter

Reprinted from the May, 1990, edition of the Mayo Clinic Nutrition Letter, Rochester, Minn.