Workplace Ergonomics and Office Chairs

John Triano, DC

Grant Cooper, MD

Spine-health.com expert featured on Back Pain Radio

Workplace ergonomics is an important part of maintaining good posture and a healthy back. Read what John Triano, PhD, a Medical Advisor for Spine-health.com and a chiropractor in Texas, and Grant Cooper, M.D., host of the radio show Back Pain Radio, had to say as they discussed guidelines for proper lifting technique, setting up an office chair and workspace and common misconceptions about workplace ergonomics.

Transcript of Back Pain Radio show on workplace ergonomics and office chairs

Below is the transcript summary from the workplace ergonomics Back Pain Radio show on March 28, 2005.

Dr. Cooper: Tell me, what is ergonomics and why is it important?

Dr. Triano: Ergonomics is a science applied to how people work and how they improve their function in work, as well as reduce the strain on their body. It’s kind of interesting that ergonomics actually got started in World War II as they tried to figure out how to put people in airplane cockpits and allow them to look out of the windscreen to see where they were going at the same time as they were looking at their instruments to see where they’d been. As a result, that’s grown now into all different workplaces.

Dr. Cooper: There are a lot of reasons that people develop pain at their workplace, but I think that one of the more common ones is bad posture. What is good posture?

Dr. Triano: Good posture is actually not a static thing. Most people think about good posture as being the classical picture of somebody sitting or standing from the side view, and they draw a line from the center of their ear through their shoulder and down through their hip. Then they say if that’s all lined up, then that’s good posture. Well, that’s fine if all you’re going to do in your life is sit still, and only for a short time, because you get awfully tired of that after a bit. Posture is a tool, and you really should look at posture as being a whole series of tools that you have on the work shelf, and you can pick the posture according to the task. Sometimes postures are very awkward, and they’re perfectly fine for very short intervals. Posture should minimize the amount of stress that occurs in the joint structures over a prolonged period of time. So, good posture is a posture that is used to accomplish a task with a minimum amount of stress on your body.

Dr. Cooper: What if your task is, say, carrying a heavy load? What is good posture in relation to that?

Dr. Triano: Carrying the heavy load is dependent on two issues – how heavy is it and how big is it? If it’s fairly small, then keeping it close to your body and being able to lift it from the ground (for example, by squatting down and bringing it between your knees) is the best technique. With a larger load that is bulky and not necessarily so easy to fit between your knees, either you need an assistant to get it lifted, or if it’s not quite that big and not too heavy, you can lift it yourself with good ergonomics and good body posture by bending forward and pulling it up. Quite honestly, bending with your knees on a big load actually pushes it further from your body than if you bend forward and lift it.

Dr. Cooper: Then you’d actually be bending forward and putting more stress on your spine.

Dr. Triano: That’s right. The key is to keep it as close to your body as possible, and that’s good posture for lifting.

Dr. Cooper: Suppose that I’ve got a heavy load, it’s not too big, I’m holding it close to my body and I have to make a turn. Are there some tips that you can give me to guide me on how to make that turn?

Dr. Triano: The most risky thing you can do is twist. The minute you start twisting your body while you carry a heavy load, you’re putting your back at real risk. Your body structure is best designed to carry heavy loads when it is facing forward. The very best thing you can do if you have to turn is to lift up that foot and turn it to the side and bring the body along with it, so that you physically turn your whole body, not twist.

Dr. Cooper: Let your legs guide you first, in other words.

Dr. Triano: Let your legs do the walking, that’s right.

Dr. Cooper: Now, suppose I have to carry this load up a flight of stairs or up a ladder. Are there some tips for how to maneuver that load in that situation?

Dr. Triano: Ladders are not really good things to be carrying heavy loads on, unless you are in the kind of situation where you can carry the load on your shoulder or with a backpack or with a sling that you can support and use your hands to continue to navigate the ladder. If you can carry it on your shoulder and it’s not so bulky that it’s causing strain on your neck, for example, that’s fine, you can usually navigate that. Otherwise, you need some sort of a backpack or a hoist system so that you can climb the ladder and use the hoist to bring it up.

Dr. Cooper: Is the type of chair that you sit on all day important, and what makes one chair ergonomically superior to another?

Dr. Triano: Chairs are one of my favorite topics in ergonomics, because so many people don’t understand the whole issue of seated workstations. People think that a good chair is one that is labeled with the word ‘ergonomics.’ What they forget is that, like posture, a chair is just another tool. You can have the most expensive and the best ergonomically designed chair in the world, but if you don’t know how to use the tool, then it doesn’t do you any more good than if you didn’t have a good chair at all. It really doesn’t need to be a special chair as much as a chair that fits you, gives you good support and minimizes the stress on your back.

Dr. Cooper: So, how should I set myself up – I have a chair, I feel comfortable and my task is to type at a computer screen for a few hours. How should I setup my workstation to minimize the amount of stress I’m going to be going through?

Dr. Triano: Well, let me first give you this big, long list of numbers that tells you how tall your chair should be. I’ll bet that would excite you to no end. That’s what people think in terms of getting instructions on how to use an ergonomic workstation. In reality, it’s a very simple process that you can define with respect to you as an individual and you can forget all the numbers, because there are six very simple principles to make any workstation comfortable for you.

Most people think that if you start with a really good chair, that’s the beginning. Actually, the chair is the second step. The first step is that you start with the work surface. Some of us work in a seated position, some of us work in a standing position, and some of us have the opportunity to work in what’s called semi-seated (it’s kind of like the bar stool). The notion is that you look at your work surface, and say, ‘I need a chair that fits that work surface.’ How do you find that chair? If you sit in the chair upright and comfortable, and you hold your arm to your side, with your elbow at 90 degrees and you turn your hand face down, that’s where the work surface should be, whether it’s a keyboard, or a desktop that you’re using, or what have you. If you have that height, it’s the proper starting point. You can move your chair up and down or you can get a different chair of the proper height to accommodate that.

After that, you have to worry about your legs. For people with back problems, leg problems, or circulation problems, if they sit in a chair that’s too tall, it will cause swelling in their feet and cause them to have pain in their legs. At the end of the day, when you get up and slip your foot back into that shoe that you took off to be comfortable, you find it doesn’t fit any more.

Dr. Cooper: Your feet swelled up.

Dr. Triano: You swelled up. Everybody swells up by the end of the day in their ankles, about 6– 8%, but if you have the wrong chair you’re going to be 10-15%, and that’s really uncomfortable.

So the next thing you do is you sit comfortably in that chair, which is now at the right height for the desk surface, and you slide your finger underneath your thigh. If you can do that comfortably, you don’t have to really work it in underneath your thigh at the front edge of the chair, that’s a good height and you’re not going to have too much pressure. If you have to really push, then you may need a foot stool to raise your feet. Those of you who are height challenged (like me) might need a foot stool so that you don’t have too much pressure, even though the chair is at the perfect height for your workspace. Now, some people are a lot taller, and they end up having this big space underneath their thigh – the opposite problem. Well, you think that would be okay, but it’s really not either, because that binds up the circulation at the back of the knee, and you end up with similar problems to having too much pressure. So, under those circumstances, you really have to go back to the work surface and make it taller, but that’s a rare problem.

So, after you’ve figured out that there’s not too much pressure, and you take your fist (as step number 3) and you push it behind your calf, then you should have the full distance of a fist length between your calf and the front edge of the chair. That is the third point and it also helps minimize the restriction of circulation and pressure.

The fourth is your back support. Most people think about having a chair that gives them really good back support – they can lean way back and be comfortable, or they have to sit ramrod straight and have the chair pushing into their lower back. In reality, what you should have is a chair that will move its back support at an angle so that it angles back just past 90 degrees or up to 90 degrees, and have a little bit of cushion that pushes your lower back forward when you’re sitting back in the chair. But, you know, a lot of people think that they’ve got a great chair with a great back, but then they sit on the front edge and don’t use the back support that is designed for good ergonomics.

Dr. Cooper: The best tool is not so useful if you don’t use it.

Dr. Triano: If you don’t use it, it’s not helpful. The fifth actually goes to the question of where is the computer screen, if you’re using a computer, as most of us do today. In the old books, they say, ‘put the top of the computer screen at eye level.’ The problem with that is – look around you – how many different size computer screens do we have these days. There’s actually a more useful measure, and it again relates to you, your physical body and structure.

If you’re sitting comfortably, having adjusted the chair to the height of the table, gotten your legs comfortable and gotten your back support nice and comfortable, relax, close your eyes and just casually look forward with your eyes closed, and then slowly open your eyes. As you do that, you’ll notice that your eyes are not horizontal; they’re sustained slightly downward from horizontal. That’s called the resting eye gaze and that’s where the center of the screen will be.

What happens then is your head will be comfortable, your eyes will be comfortable, and as you are working, you’ll have the minimum amount of stress on your neck and shoulders from having to crane your neck (like those of us who use bifocals). You often see them sitting in their chair and their neck is arched backwards and they’re staring out the bottom of their glasses, and they wonder why their neck hurts and they have a headache.

Dr. Cooper: The perfect recipe for a headache.

Dr. Triano: Perfect recipe! The other person is a male who thinks he’s doing really great in a nice, tall chair and he’s leaning far forward looking straight down at the keyboard trying to find the keys – he does that all day, and that’s tough.

Then, finally, the last thing that we adjust is the armrest. The armrest, with all of these other things adjusted properly, with your arms in that first position, 90 degrees, elbows bent, the armrest should just support the elbow. It shouldn’t jam it up into your ear and it shouldn’t cause you to flare out like a bird trying to launch into space. Rather, it should just support your elbow and take the weight off of your shoulders. In that kind of support, you have the foundations for working for most of your day with less discomfort.

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