美国国家公共电台 NPR To Fix That Pain In Your Back, You Might Have To Change The Way You Sit（在线收听）

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Researchers have been looking at how Americans are sitting and how bad it is for our health. Some have even called sitting the new smoking. And they say it's contributing to an epidemic of back pain. But what if the problem isn't how much we're sitting but the way we are doing it? NPR's Michaeleen Doucleff explains how Americans have lost the art of sitting and how they can get it back.

MICHAELEEN DOUCLEFF, BYLINE: There's this idea that Americans sit way more than any other culture out there, that for the first time in human history we've created a sitting culture. But David Raichlen at the University of Arizona says that's not actually correct.

DAVID RAICHLEN: No. I mean, not from our data.

DOUCLEFF: Raichlen is an anthropologist. He studies modern hunter-gatherers.

RAICHLEN: We work with this group, the Hadza, out in Tanzania.

DOUCLEFF: The Hadza's lifestyle is about as close as you can get to seeing how early human ancestors might have lived. Today the Hadza live off wild food - think tubers, honey, barbecued porcupines. And to get this food, there's no doubt they are active.

RAICHLEN: They climb. They do a lot of upper body work when they pound nuts and they do a lot of digging and that kind of a thing.

DOUCLEFF: On average, they spend about 75 minutes each day exercising, which is way more than most Americans do. But do the Hadza sit less than we do? No one had actually gone out and measured it, so Raichlen and his team strapped heart rate monitors onto nearly 50 Hadza adults, then measured how often each day they were just, well, sitting around. The results shocked him.

RAICHLEN: It's, like, 10 hours a day. So it's about as much as we are.

DOUCLEFF: Ten hours each day - that's basically what I do at my desk each day. But here's the thing. The Hadza don't seem to have the back issues that we Americans have even as they age.

RAICHLEN: People are highly active across the lifespan. You know, there are some declines in activity with age, but nowhere near what you get in the U.S.

DOUCLEFF: So I asked him if he thinks the problem isn't how much Americans sit but the way we sit.

RAICHLEN: Yeah, I definitely think that that's probably a big part of the story.

DOUCLEFF: Now, I know what you might be thinking. Raichlen is an anthropologist, not an expert on backs or back pain. But Dr. Nomi Khan is. He's a spine surgeon at Sutter Health's Palo Alto Medical Foundation. And he agrees with Raichlen.

NOMI KHAN: Most of us do not sit well. So we've certainly been putting a lot more stress on our spines.

DOUCLEFF: So do you think if we change the way we sit it could help to decrease back problems?

KHAN: Yes. I think we should sit less, and I think we should sit better.

DOUCLEFF: That's a key difference between us and the Hadza. They, unlike us, know how to sit. Khan says that most people here, even kids, have gotten in the habit of sitting in one particular way that is hurting our backs. You might not realize you're doing it, but it's super easy to see in other people. Here's an experiment. Go over to somebody sitting down or look across the office. Don't look face on but from the side so you can see the shape of their backs. There's a high chance their back is curving like the letter C. The shoulders curve over, and the butt or bottom curves under.

KHAN: Most people, they round out their back when they sit.

DOUCLEFF: For some people it looks more like a cashew nut than a C. But Khan says it's still bad for the back.

KHAN: So that's the improper way of sitting. Their spine is in an improper position. And they tend to have more back problems.

DOUCLEFF: The back problems crop up because over time, sitting like a C can damage spinal disks. William Marras directs the Spine Research Institute at Ohio State University.

WILLIAM MARRAS: So this is this little shock absorber in between the vertebrae that allows you to move and bend and twist. And when that thing gets messed up, you've got real problems.

DOUCLEFF: You can think of the spinal disks as these little jelly doughnuts stuffed with soft, gooey jam. Sitting like a C presses on one side of the doughnut. If you do it long enough, some of the jelly can squirt out.

MARRAS: That's very bad for the disks because it can push against nerves, and it can rupture. And - so everything we do in biomechanics typically tries to protect that.

DOUCLEFF: So how do you straight out the C and start protecting those disks? Jenn Sherer has been helping people do just that for eight years at her studio in Palo Alto. She says our culture focuses on trying to fix the upper body. We hear people say sit up straight, and the first thing we do is stick our chest out.

JENN SHERER: You say the word spine, and that's what everyone does, is they lift their chest 'cause they want to have proper posture. And I'm like, no, that's what causes more back pain.

DOUCLEFF: That's going to make things worse?

SHERER: Yes, it makes things worse.

DOUCLEFF: Instead, Sherer says, we need to focus on another body part, one that's farther down, below the waist.

SHERER: The pelvis.

DOUCLEFF: Or another way to put it - focus on your bottom.

SHERER: The most important thing to change to reduce back pain is your pelvis position. It's like blocks. If the blocks at the bottom aren't set and aren't sturdy, then the top has no chance.

DOUCLEFF: So to fix your pelvis, Sherer says you have to imagine that you have a tail just like a dog right at the base of your spine.

SHERER: We need the pelvis to be positioned in a way where if you had a tail, it could wag.

DOUCLEFF: In other words, for proper spine alignment, your bottom needs to be out behind your spine. Sherer says right now most people do the opposite. We tuck our tails under when we sit.

SHERER: Sitting within a C curve, you'd be sitting on your tail.

DOUCLEFF: So it's kind of like a dog that has his tail between his legs.

SHERER: Yes, very scared or frightened.

DOUCLEFF: And so then how do we get our tail out?

SHERER: Do you want me to teach you?

DOUCLEFF: Yeah, sure, sure, sure.

Sherer says before you sit, have your legs about 12 inches apart. As you sit...

SHERER: Poke your butt out.

DOUCLEFF: Toward the back of your chair so when you land on the chair, your bottom is behind your spine. You can kind of put your hand back there and check. Sherer says that when that happens, your tail untucks, and some muscles in your legs will start to relax.

SHERER: Can you feel that?

DOUCLEFF: Ooh, yeah.

And for me, this muscle relaxation felt really good.

SHERER: You feel all those releases?

DOUCLEFF: Ooh, it's tingling. It's tingling, like, up my body. Wow.

For decades, I've been sitting with my pelvis tucked in. And it wasn't easy to fix. But I've had a lot of back pain, so I was motivated to try this. I spent months working to get my tail to come out so it could wag. And after mastering it, I thought I'd give Dr. Nomi Khan visit to see what he thought.

KHAN: You're sitting perfectly because what you're doing is you're basically sticking your butt backwards.

DOUCLEFF: Which allows my spine to stay straight, protecting those all-important spinal disks. Michaeleen Doucleff, NPR News.

(SOUNDBITE OF VUREZ'S "GLORIOUS CRYSTAL GLEAM")