Four out of five adults have suffered from back pain at some time in their lives. Many live with it every day. It’s one of the top five reasons people go to the doctor or stay home from work. It costs the economy billions.

In another one of those physiological Catch-22s, exercise can trigger back pain in people who do it too long or too wrong, but just sitting there can make it worse. So what’s a body to do?

Erika Jacob knows. A physical therapist with Denver Physical Therapy, she sees more back pain come limping into her office than any other ailment. Some of it just happened, on the racquetball court or in the gym or in a car crash, and some of it is chronic.

“Unfortunately, I’m seeing a lot more people in the 30-to-40 population,” she says. “It’s our sedentary lifestyle.”

Research shows that 40 is the peak age for back injury, and back problems are the biggest cause of disability for people under 45.

Most back pain goes away by itself after a week’s break from whatever activity caused it. But people with chronic back pain usually have a lot of muscle tightness, and inactivity just makes that worse.

“You’ve learned to adapt your body to the pain, and you don’t want to do things that cause you pain, so you slowly stop doing things,” Jacob says. Simple changes — your grip on the steering wheel, the position of your computer keyboard, the type of chair you use — can make a big difference.

“Posture is huge,” Jacob says. She considers getting people to stand straight, sit straight and move right one of her missions in life.

“Your head needs to be over your body rather than sitting in front of your body, because then it weighs twice as much, putting that much more stress on your neck muscles, which is why people end up with so much tension,” Jacob says.

(DENVER, CO. JULY 28, 2004) Back pain. (photo by ELLEN JASKOL/ ROCKY MOUNTAIN NEWS)

Make sure your head is in a natural, neutral position and you’re not jutting your chin, which causes a lot of tightness at the base of your skull.

“I tell people I’m trying to stack one vertebra on top of another, because you’re much more stable there,” Jacob says. Knee and foot position matter, too. “All those things filter up to the head.”

One of the biggest causes of chronic back pain is lack of strength in the back and abdominal muscles that encircle the body like a corset and support the trunk and spine. Time spent building those muscles is an investment in your future health.

“There are so many things to do, and taking care of yourself is always low on the list,” Jacob says. “All it takes is one wrong move to give you a problem.”

CAT CAMEL

How To: Assume an all-fours position with hands lined up under your shoulders and knees hip-distance apart. Allow your tummy to sag; keep your chin lifted. Tighten your abs as you return to the starting position. Continue to tighten your abs and your butt as you bring your chin to your chest and round your back.

Hold for a count of 8. Start with 10 reps, and work up to 20.

Variation: This exercise can be done standing with knees bent and hip-distance apart, hands just above the knee.

BIRDDOG

How to: Assume an all-fours position, with hands lined up under your shoulders and knees hip-distance apart. Slowly lift and straighten your right leg so that it’s about a foot off the ground, at hip level or below. While your right leg is extended, lift the left arm in front of you, level with your shoulder or below. Keep your focus on the floor. Hold for a count of 8. Do 10 reps on each side.

Variation: This exercise can be done over a fit ball. It can also be done lying on your stomach if you have hand, wrist or knee problems. Lift the leg and opposing arm just a few inches.

BRIDGE

How to: Lie flat on your back, knees bent, arms at your sides. Tighten your abs and your butt as you slowly lift your hips off the ground. Hold for a count of 8. Start with eight to 10 reps, then work up to 20.

Variation: This exercise can be done with your legs on a fit ball.

CHILD POSE

How to: Start on all fours. Sit back so that your butt is on your heels. As you do that, extend your arms along the floor and line up your head between your shoulders. Hold for a count of 10.

COBRA

How to: Lie on your stomach with your arms close to your body and your hands lined up under your shoulders. Slowly push yourself up. Keep your chin lifted and eyes focused up. Hold for a count of 8. Work up to 10 reps.

Variations: If lifting your chin strains your neck, keep your head level and eyes forward as you push up. As you become stronger, try to push yourself higher by straightening your arms more. Be sure to keep your hips close to the floor.

AB MARCH

How to: Lie on your back, knees bent, feet on the floor. Slowly lift your right leg toward your chest, then your left. Now return your right foot to the floor, then the left. Keep the small of your back on the floor. Do 10 reps.

Variation: To make it easier, lift and return one leg at a time.