The art and science of sitting
The gospel of ergonomics according to Eric Niewenhuis
By John Quinlan, Journal staff writer | Posted: Saturday, April 12, 2008
St. Luke's Regional Medical Center physical therapist Eric Niewenhuis demonstrates good posture for sitting in an office chair on March 19, 2006, at the hospital. (Staff photo by Jerry Mennenga)
SIOUX CITY -- Most of us spend as much time in our chair at work as we do in our bed at home. For many, the chair may be even more familiar than the bed. (You know who you are.)
So it would seem to be in our best interest to find the right chair and sit in it the best, most ergonomically correct way possible, our feet flat on the floor, our back supported and our armrests properly aligned.
So we consulted a specialist, physical therapist Eric Niewenhuis of St. Luke's Regional Medical Center, one of the public faces of that institution and a near-perfect specimen of physical fitness himself.
People at St. Luke's sit up a little straighter when Niewenhuis shows up. They know he's The Man when it comes to posture and proper body mechanics.
When he joined St. Luke's in 1999, Niewenhuis was trained in the IMPACT program, which stands for Injury Management Prevention and Cost Containment. And since that time, the chairs have gradually improved in quality throughout the hospital. IMPACT is an egonomics training program that looks at the posture, the body mechanics and kind of structural setup and work process for the employees.
"I've been doing that both internally here at St. Luke's and with companies in the tri-state area since that time," he said.
Ergonomics is commonly thought of as how companies design tasks and work areas to maximize the efficiency and quality of their employees' work. The field has been around a while, but has really picked up steam in recent years, Niewenhuis said.
"It's been so much more addressed now because our culture is so much more looking toward the preventive end of health care and where these injuries and things are coming from -- and to keep people healthy and happy and safe, both in the workplace and at home," he said. "And ergonomics is a very big part of that."
People are looking at the engineering, the height and distribution and process of work, how chairs are set up and how they can reduce the biomechanical stresses to the body, Niewenhuis said
As far as chairs are concerned, Niewenhuis has noted real progress just in the past few years. When he started at St. Luke's, he noted that the only adjustability on most chairs was raising the back rest up or down. Some chairs didn't even allow that. The seat angles couldn't be changed. And occasionally he will spot one of those dinosaurs around the St. Luke's campus.
Tips from the master
One thing you always want to look for with a chair, ergonomically speaking, is the back rest height, Niewenhuis said.
"You want to be able to raise and lower that back rest. You also want to be able to change the angle of the back rest," he said.
For the best lumbar support, he recommends having the back rest set almost as high as it will go, centering in the small of your back. This helps spread and distribute the stress across your spine.
The next most important thing is the seat angle, which is called your seat pan. "You want to be able to kind of tilt that forward, have it neutral and/or tip it back," he said. "The ideal posture for your body is to have it tipped slightly forward."
Tipping the seat forward is particularly important for female workers, he said. Women tend to have shorter legs that might dangle, their legs pulling back underneath the chair and not touching the floor -- and touching that floor is important. "Because the more that anybody, man or woman, pulls their legs underneath their chair, he more you compress the cartilage in your knees which over time ties a lot of damage to those knees," he said. "So ideally, the more you sit, the more you want to try to keep your knees square."
Arm rests are especially important for those office workers not in a corner work station, where the arm rests just get in the way.
"But if you're not in a corner and you're directly facing the work station, you want to be able to have arm rests that can go up and down," he said. "And then more of your upper-line chairs, you can actually slide those arm rests in and out, and you can rotate them in and out."
This is an especially nice feature if the chair has more than one user since everyone has a different shoulder width, among other body size and shape issues.
Niewenhuis also cautions against reaching too far for your mouse. Reaching for a wayward computer mouse puts a lot of stress on your neck and shoulders. Over time, that can cause elbow, wrist and hand problems, he noted.
Lightly resting your forearms while you are typing or keyboarding reduces stress on your upper back, neck and shoulder, avoiding the fatigure that these posture muscles face on a daily basis. And the longer you sit, the more you are compressing the blood vessels and nerves that go up to your neck and shoulders.
One thing you can do to alleviate this is to adjust the back rest height, Niewenhuis said. "Most often, from what I've found, you almost have to put this in the highest position to properly support your lumbar spine, that lower back and your mid to upper back," he said. "So I'm going to put that in the highest position."
The next thing you want to do is change the angle of your feet by rotating the angle of the chair. "You ideally want to have that either neutral or, even better, tipped a little bit forward," he said. "Why you want to do that is because that gets your hips higher than your knees. Then when your feet are flat on the flooor, that helps to put kind of an inward curve on your lumbar spine, that lower back, and it pulls your head back over your shoulders. So it can help you to sit up a lot straighter and reduce the risk for your posture the longer you have to sit."
Listen to your body
Niewenhuis said it is important to change your position during the day, taking little pit stops by maybe leaning back a bit, using a switch lever common to most office chairs. Move the back rest forward or back a little, then lock it in so you're not swinging back and forth, he advised.
When to move your body, stretch, get up and walk around depends, he said, on listening to your body's "red flag of fatigue."
When your body says, "I'm tired. I'm getting stiff. I'm kind of sore." it's time to change your position.
Varying your posture a little bit each day helps get the blood supply to your back and hips in a little different way.
"But most of your day, you want to spend with it a little more upright," he said.
If the chair is too low, you tend to lean back during the day. And because the chairs aren't usually high enough to support your head, your body is going to compensate and your head and shoulders are going to stoop, he said.
"So you're really going to increase the risk of neck or shoulder and muscular/skeletal disorders and sprains and strains," he said.
In addition to trauma risks to your elbow, wrists and hands, poor posture can flatten out your lower back and put you at risk for problems to the lower back, sprains and strains the risk of disc injuries returning, he said.
"So you really want to work on keeping things firmer for most of the day -- sitting up straight," he stressed.
Then, when you get home from a long day's work, nothing beats your La-Z-Boy -- even ergonomically -- because you can lean back with good head support and not nearly as much stress on your spine. The stress to each disc is actually less when you recline back.
Unfortunately, he noted, most people can't work and recline at the same time.
Ergonomics, it seems, still has a way to go.
Watch your posture!
One of the most important things is not only the chair but the worker's posture habits, Eric Niewenhuis said.
Some workers, for instance will slouch whether they are in an expensive new office chair or sitting on a wood stool. A good chair will help them straighten up, but even then, they have to make an extra effort not to slouch.
Another key health point is to try to not cross your leg when you're sitting in a chair. Women tend to sit with one leg dangling over the other, men with one leg crossed over the other, their knees far apart. Neither way is good.
"Longer term, all of these postures externally rotate your hip," he said, "and they tighten your pirifirmis muscle, which is a powerful external rotator. And right after that powerful hip external rotator is your sciatic nerve. So people that are diagnosed with sciatica, that is one of the primary reasons. All the time that we sit and stand with exernally rotated hip, full-out postures, we're sitting with our legs crossed or knees out."
Keeping our toes straight ahead or "slightly toed out" is the ideal work posture for most of the day.
"The more you an stay in that posture, the less stress to your lower back, your hips, your knees," he said.
So it would seem to be in our best interest to find the right chair and sit in it the best, most ergonomically correct way possible, our feet flat on the floor, our back supported and our armrests properly aligned.
So we consulted a specialist, physical therapist Eric Niewenhuis of St. Luke's Regional Medical Center, one of the public faces of that institution and a near-perfect specimen of physical fitness himself.
People at St. Luke's sit up a little straighter when Niewenhuis shows up. They know he's The Man when it comes to posture and proper body mechanics.
When he joined St. Luke's in 1999, Niewenhuis was trained in the IMPACT program, which stands for Injury Management Prevention and Cost Containment. And since that time, the chairs have gradually improved in quality throughout the hospital. IMPACT is an egonomics training program that looks at the posture, the body mechanics and kind of structural setup and work process for the employees.
"I've been doing that both internally here at St. Luke's and with companies in the tri-state area since that time," he said.
Ergonomics is commonly thought of as how companies design tasks and work areas to maximize the efficiency and quality of their employees' work. The field has been around a while, but has really picked up steam in recent years, Niewenhuis said.
"It's been so much more addressed now because our culture is so much more looking toward the preventive end of health care and where these injuries and things are coming from -- and to keep people healthy and happy and safe, both in the workplace and at home," he said. "And ergonomics is a very big part of that."
People are looking at the engineering, the height and distribution and process of work, how chairs are set up and how they can reduce the biomechanical stresses to the body, Niewenhuis said
As far as chairs are concerned, Niewenhuis has noted real progress just in the past few years. When he started at St. Luke's, he noted that the only adjustability on most chairs was raising the back rest up or down. Some chairs didn't even allow that. The seat angles couldn't be changed. And occasionally he will spot one of those dinosaurs around the St. Luke's campus.
Tips from the master
One thing you always want to look for with a chair, ergonomically speaking, is the back rest height, Niewenhuis said.
"You want to be able to raise and lower that back rest. You also want to be able to change the angle of the back rest," he said.
For the best lumbar support, he recommends having the back rest set almost as high as it will go, centering in the small of your back. This helps spread and distribute the stress across your spine.
The next most important thing is the seat angle, which is called your seat pan. "You want to be able to kind of tilt that forward, have it neutral and/or tip it back," he said. "The ideal posture for your body is to have it tipped slightly forward."
Tipping the seat forward is particularly important for female workers, he said. Women tend to have shorter legs that might dangle, their legs pulling back underneath the chair and not touching the floor -- and touching that floor is important. "Because the more that anybody, man or woman, pulls their legs underneath their chair, he more you compress the cartilage in your knees which over time ties a lot of damage to those knees," he said. "So ideally, the more you sit, the more you want to try to keep your knees square."
Arm rests are especially important for those office workers not in a corner work station, where the arm rests just get in the way.
"But if you're not in a corner and you're directly facing the work station, you want to be able to have arm rests that can go up and down," he said. "And then more of your upper-line chairs, you can actually slide those arm rests in and out, and you can rotate them in and out."
This is an especially nice feature if the chair has more than one user since everyone has a different shoulder width, among other body size and shape issues.
Niewenhuis also cautions against reaching too far for your mouse. Reaching for a wayward computer mouse puts a lot of stress on your neck and shoulders. Over time, that can cause elbow, wrist and hand problems, he noted.
Lightly resting your forearms while you are typing or keyboarding reduces stress on your upper back, neck and shoulder, avoiding the fatigure that these posture muscles face on a daily basis. And the longer you sit, the more you are compressing the blood vessels and nerves that go up to your neck and shoulders.
One thing you can do to alleviate this is to adjust the back rest height, Niewenhuis said. "Most often, from what I've found, you almost have to put this in the highest position to properly support your lumbar spine, that lower back and your mid to upper back," he said. "So I'm going to put that in the highest position."
The next thing you want to do is change the angle of your feet by rotating the angle of the chair. "You ideally want to have that either neutral or, even better, tipped a little bit forward," he said. "Why you want to do that is because that gets your hips higher than your knees. Then when your feet are flat on the flooor, that helps to put kind of an inward curve on your lumbar spine, that lower back, and it pulls your head back over your shoulders. So it can help you to sit up a lot straighter and reduce the risk for your posture the longer you have to sit."
Listen to your body
Niewenhuis said it is important to change your position during the day, taking little pit stops by maybe leaning back a bit, using a switch lever common to most office chairs. Move the back rest forward or back a little, then lock it in so you're not swinging back and forth, he advised.
When to move your body, stretch, get up and walk around depends, he said, on listening to your body's "red flag of fatigue."
When your body says, "I'm tired. I'm getting stiff. I'm kind of sore." it's time to change your position.
Varying your posture a little bit each day helps get the blood supply to your back and hips in a little different way.
"But most of your day, you want to spend with it a little more upright," he said.
If the chair is too low, you tend to lean back during the day. And because the chairs aren't usually high enough to support your head, your body is going to compensate and your head and shoulders are going to stoop, he said.
"So you're really going to increase the risk of neck or shoulder and muscular/skeletal disorders and sprains and strains," he said.
In addition to trauma risks to your elbow, wrists and hands, poor posture can flatten out your lower back and put you at risk for problems to the lower back, sprains and strains the risk of disc injuries returning, he said.
"So you really want to work on keeping things firmer for most of the day -- sitting up straight," he stressed.
Then, when you get home from a long day's work, nothing beats your La-Z-Boy -- even ergonomically -- because you can lean back with good head support and not nearly as much stress on your spine. The stress to each disc is actually less when you recline back.
Unfortunately, he noted, most people can't work and recline at the same time.
Ergonomics, it seems, still has a way to go.
Watch your posture!
One of the most important things is not only the chair but the worker's posture habits, Eric Niewenhuis said.
Some workers, for instance will slouch whether they are in an expensive new office chair or sitting on a wood stool. A good chair will help them straighten up, but even then, they have to make an extra effort not to slouch.
Another key health point is to try to not cross your leg when you're sitting in a chair. Women tend to sit with one leg dangling over the other, men with one leg crossed over the other, their knees far apart. Neither way is good.
"Longer term, all of these postures externally rotate your hip," he said, "and they tighten your pirifirmis muscle, which is a powerful external rotator. And right after that powerful hip external rotator is your sciatic nerve. So people that are diagnosed with sciatica, that is one of the primary reasons. All the time that we sit and stand with exernally rotated hip, full-out postures, we're sitting with our legs crossed or knees out."
Keeping our toes straight ahead or "slightly toed out" is the ideal work posture for most of the day.
"The more you an stay in that posture, the less stress to your lower back, your hips, your knees," he said.
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