You're Sitting on a Time Bomb

By Paul Scott

If you're deskbound, your back is doomed--unless you learn to love and protect your spinal curve. Here's how

Your office chair--the foul line for every Nerf free throw and your box seat on the working world--has you fooled. You think it makes you powerful when it really makes you weak. You think it rests the machinery of your back when it's silently causing your back to compress, crush, and fail. You think its adjustable armrests and hydraulic height control offer you choices, but the most important option of all--the option to stand up and move--is the critical way your chair undermines you.

We live in a free country, but sitting is mandatory. In the late 1980s, office workers spent 70 percent of their days seated. Today's desk jockeys ride the unforgiving chair 93 percent of the time. Those who are paid to do clerical work may spend closer to the full 100 percent. That's just the sitting required to earn a living. Add to that the growing number of hours you spend seated while commuting, watching 24, tracking your NCAA pool results, or doing pretty much anything on, say, a Bowflex, and the remainder of your day is one long game of musical chairs. Life treats you like the waiting room at the DMV. Take a number, be seated, and wait your turn for the big back attack.

But at least seated jobs are safer, right? After all, you can't crush a finger in the machinery of investment banking. Well, if desk duty lowers your risk of on-the-job amputation, it's now clear that sitting for a living will slowly but surely increase your risk of developing back problems. Occupational sitting can damage your back in a variety of ways, but the real demon unleashed by sitting comes from the mundane fact that your back is pulled out of its natural position when you place your legs at a 90-degree angle to your hips. Studies show that when you drop into a chair, your hips stop rotating after the first 60 degrees of descent. To move your legs the final 30 degrees into position, "the muscles of the back of your thighs pull the bottom of your pelvis forward to tip it backward," says Galen Cranz, Ph.D., a professor of architecture at the University of California at Berkeley and the author of The Chair, a withering criticism of our most ubiquitous piece of furniture.

"That," says Cranz, "flattens the lumbar curve." (If this were a horror movie, lightning would strike right now.)

For decades, researchers have argued that flattening the lumbar curve--the concave segment of the spine also known as the small of the back--leads to pain. But until Stuart McGill, Ph.D., first fired up his ominous-looking disk-herniation machine, no one had wrecked an actual spine to prove the point.