The Science of Sitting Made Simple

Gregg Carb: Well, Rachel, in answering that question, I'd first like to define terms so we have a common understanding. Posture refers to body position and alignment. Good posture practice refers to both maintaining the normal shape of the spine and satisfying the body's ongoing desire for motion. So, posture is really important on a few different levels, but perhaps the two most important are health and image. Health in posture refers to the predictable consequences of poor posture practice on the body, such as the spinal and soft tissue degeneration, including degenerative disc disease, compression of internal organs, muscular strain and the suppression of certain important hormones, such as lipase, which increases the risk of cardiovascular disease, diabetes and obesity. Image in posture refers to body language and what your posture is telling others about you, for example, during a job interview, your posture will say as much about you as you the clothes you're wearing for that interview. As I said in my book, there's something subconscious in us that still recognizes good body form when we see it and associates that quality with grace, health, instinction. Now the opposites also apply. I think that today, because so many people have minimal posture awareness, someone with remarkably good posture is more likely to be noticed and remembered in a positive way.

Rachel Salaman: Now most people think of a standing position when they hear the word posture, but your sitting posture is just as important, isn't it?

Gregg Carb: Sitting posture is perhaps more important because most people spend the majority of their waking hours these days in a seated position, including work time, commuting, eating, relaxing and for many forms of electronic entertainment, such as watching TV. When people stand, they tend to fidget a bit; they shift their weight and move around more, compared to sitting. So standing's typically more dynamic and sitting more static, which makes proper sitting all the more important because one position is often being held for a longer time. Also, poor posture has the possibility of increasing disc pressure higher than other body positions, so sitting is potentially more damaging than other common body positions.

Rachel Salaman: And this must be something you see in your practice all the time?

Gregg Carb: Yes, absolutely. It's a real common problem for people to have lower back and neck and mid back problems just, you know, it can run the gamut of problems in the body related to, you know, their sitting posture because, particularly where I work here in the financial district, there's a lot of desk workers who have these kind of problems.

Rachel Salaman: On the more positive side, some doctors have suggested that your sitting posture can actually improve productivity and performance, how does that work?

Gregg Carb: Well, we know quite well, through scientific investigation, that poor posture practice causes problems like increased muscle joint and disc strain in the body, general fatigue and a higher incidence of various repetitive strain injuries. So the short term outlook is that a person with poor posture habits is more likely to be in some discomfort, which can be pretty distracting when you're trying to work, meaning you're likely to get less done, but taking more time to do it. The long term outlook is that repetitive strain injuries can become so severe that they can literally disable a person and that would be a maximum loss of productivity and performance. Good posture practice, on the other hand, which includes, you know, body position and alignment, good ergonomics and periodic activity breaks has been associated with significantly lower levels of discomfort and repetitive strain injury, so good posture is beneficial simply by way of prevention and avoiding a negative outcome. In addition, the activity break component of good posture practice stimulates blood flow and breathing, which provides a direct benefit in terms of mental sharpness and emotional outlook.

Rachel Salaman: So who needs to start thinking about their sitting posture, just those who are worried about it or everyone?

Gregg Carb: Well, gravity doesn't discriminate between people that believe in it and those that don't. Everyone at every moment is being pulled toward the center of the earth with great force, and how efficient you are at managing that compressive force over a lifetime will have a significant effect on your body's frame, and on your health. In fact, it's been shown that the health risks associated to poor posture practice overall are as significant as the health risks associated with smoking, direct sun exposure, and high cholesterol. That means that the average person, at this time in our society, really has little appreciation and knowledge of the risks associated with overly sedentary poor posture habits. So knowing what I do, I think that everyone should be concerned with increasing their understanding and attention to good posture practice. Now that being said, this information is primarily aimed at desk workers and others that sit a lot throughout their day.

Rachel Salaman: Well, in your new book, The Science of Sitting Made Simple, you outline ten steps to getting a better posture, or better posture practice, let's talk briefly about those. The first one is "Understanding your spine's normal shape", what is the spine's normal shape?

Gregg Carb: The spine's normal shape, it's first important to remember that the spine is very three dimensional, so the shape will appear differently, depending on how you're looking at it. From the back view, as if someone were standing in front of you, the spine should simply be straight, running from the bottom of the head down to the top of the pelvis. From the side view, that same spine should not appear straight at all, but rather, it should have several contours. One arching forward in the neck area, one arching backward in the mid back area, and one arching forward again in the lower back area. There are a few smaller spinal curves lower down in the pelvis, but they don't generally change with posture. So basically, we have a vertical spine, as seen from the back or front view, and three major contours in the spine, as seen from the side view. I'd also like to add that this normal shape of the spine has a person's head at the top, the ribcage in the middle, and pelvis at the bottom, all perfectly aligned, from top to bottom, front to back, and from side to side.

Rachel Salaman: So why is it important to understand all that?

Gregg Carb: Well the basic concept of good posture is maintaining a neutral spine position, so in order to do that, you have to know what the normal shape of the spine is. Then you should be able to better appreciate poor posture positions that are bending the spine out of its normal shape. For example, we talked about how the spine is normally arched forward in the neck area. If a person likes to read with the book placed on their lap, we know that their head is going to be bent down, which actually bends the spine backward in the neck area. So I think a person can better understand how bad it is to read with your head down and your neck bent backward, knowing full well that the normal shape of the neck is actually arched forward. In fact, if the basic concept of good posture is maintaining a neutral spine position, then the basic concept of poor posture would be bending your spine out of shape. So we must, you know, understand the normal shape of the spine to appreciate both good and bad posture.

Rachel Salaman: Well, the second step you call "Keeping it together" and that focuses on the soft tissue that holds the spine together. What should we know about this and how does it affect good posture practice?

Gregg Carb: Well connective tissues hold the spine together and also play a major role in guiding and limiting spinal motion. In the book I say that the spinal bones give rigid support to the body's frame, while the soft tissues give flexible support. So the connective tissues are things like disc and ligaments and, to some extent, muscles that join the spine together segment by segment. Most people don't directly injure their spinal bones through poor posture. A bone injury is a fracture. However, people often injure their soft tissues and that is a strain or a sprain. Now here's another way to think about it. If we were able to express posture changes in the body as some, sort of, equation, for most people the spinal bones would more or less be a constant in that equation and the soft tissues would be the variable.

Rachel Salaman: How does knowing this actually affect how we view our own posture?

Gregg Carb: Well, we just talked about the soft tissues as being variable. That's because their connector soft tissues are adaptable. Their flexibility is what gives us a range of motion, but they can also become chronically overstrained. In poor posture, as we know, the spine is bent out of its normal shape. When this is repeated, over long periods of time, the connected soft tissues actually begin to adapt to the position you're most often in, and this gradually changes your alignment. So people tend to repeat the same posture patterns like sitting with their backs rounded, standing with their head and shoulders forward and sleeping all curled up in a fetal position. What they're actually doing is molding their position; they're molding their spine into a new shape.

Rachel Salaman: Gosh, and then can they get back out of that shape?

Gregg Carb: Yes they can, and that's – that is part of what we call "Extension Stretching", which comes a little bit later, you know, in the book, but absolutely, there are ways to reverse that process.

Rachel Salaman: Well, you've covered step three in your book, which is learning how you get bent out of shape, with your explanation there. The next step is, "Understanding how degeneration happens", that sounds a bit scary too. Isn't that something that only affects older people or not?

Gregg Carb: Well, let me start by saying that the wear and tear process that we're talking about affects both spinal bones and soft tissues. So these are things like osteoarthritis, degenerative disc and scar tissue. For the most part, older people have more degeneration simply because they've been around longer to accumulate the damage. So it really matters how long you've been exposed to adverse stresses and strains. The scary thing is that young people are subjecting themselves to postural strain early in life like never before, and they're going to have a long road ahead for all this wear and tear to show up, and cause problems. So it's really a concern for everyone.

Rachel Salaman: Well, step five is "Understanding your correct posture", now you've made the case for why it's important, can you tell us what our correct posture should be and give us any tips for keeping in mind what we should be doing?

Gregg Carb: Well, essentially, I find that many people with poor posture practice have little awareness of the natural forward arch that exists in their lower back. So one of the exercises in this step of the book is to stand on your own two feet, and back up slowly against the wall or a door and then place one hand behind you in that space, just above your hips and below your ribcage to feel the space in your lower back. Most people are surprised to feel how significant that space is and the problem is that most people flatten, or round out their lower back, when they sit. So the correct posture, when you're standing or sitting, is the posture that maintains the natural forward arch in the lower back.

Rachel Salaman: Is that something we can just correct by thinking about it?

Gregg Carb: Well, thinking about it and having awareness of that is definitely, you know, an important step, and there are also devices and proper chairs that will help to facilitate that as well.

Rachel Salaman: How much of all this is actually about having the right chair, in the end?

Gregg Carb: Well, it can make a significant difference in that public seating typically has very poor support for the lower back, so it's very difficult to maintain a good proper sitting posture in most public venues, such as stadiums and park benches and bleachers and, you know, even commuting on the bus or the train. So some accommodation usually has to be made by people to maybe carry around a little cushion, like a lumbar support, to fit into their lower back to help that out. Even without proper seating, or any seatback at all, just having the awareness of not allowing your back to round out, you can still, you know, help yourself and not succumb to the poor posture that most of the people around you are demonstrating.

Rachel Salaman: If someone was going out and buying a new office chair tomorrow, what should they really be looking for, to help them get this posture right?

Gregg Carb: Well, they would be looking for a chair that's basically as adaptable as possible to their particular, you know, body shape, so chairs come in all shapes and sizes and have actually quite a few accessories, so they want to find a highly adjustable chair that, you know, they can adjust the seatback, they can adjust the seat pan, which is the bottom part that you sit on, that goes up and down, that has rollers or castors on it, so essentially, the more adaptable or adjustable the chair is, the more likely they are to get it to fit to their particular body size. Chairs run the entire gamut in price. They can be, you know, a few hundred US or, you know, up to a thousand US dollars or more, and the chairs that cost more typically, have more features, but you can still find a reasonably priced chair that has good adjustability and essentially, in the end, you know, how you fit that chair with your body will be the important thing, so just like you would try on a pair of shoes, you really do have to go to a showroom and try on the chair to make sure that it fits comfortably for your body size.

Rachel Salaman: So you sit naturally, as you've described it, with this curve in your lower back, and then you try and get the chair to fit you, so that it supports you in that position?

Gregg Carb: Yes, and I think it's worthwhile to go through that exercise that we talked about, about standing or, you know, and backing up slowly against the wall or a door and be aware of the arch of your lower back and exactly how much of it is there, that's essentially, how much you need to support when you are sitting and for most people, it's surprising that they have a good amount of depth for that arch of the lower back and that they do need to support when they're sitting.

Rachel Salaman: Well, back to your ten steps, and step six is "Sitting up when you sit down", can you talk us through that?

Gregg Carb: Sure. My premise for this is that good posture essentially, comes down to one important concept and that concept is to keep the ribcage upright. If you think about it, almost everything else in your body attaches to your ribcage: your head and neck, your arms and shoulders, and your lower back. So instead of trying to do ten things at once, to track your posture, I recommend that all you need to do is keep your ribcage upright and the position of your head, shoulders and lower back will all automatically improve. Now, that being the case, when you sit, as we've just discussed, you're going to need a good chair with a seatback that is upright and locked in place, ideally with a well fitting lumbar support to fit into that forward arch of your lower back. Then you need to sit well back into your chair and place your upper bodyweight fully against the seatback with your feet flat on the floor or on a footrest. This actually helps to even out your weight distribution over a larger area of your body, so you're not overstressing any one part.

Rachel Salaman: Well step seven is all about awareness, and how it can prevent us from slumping. Do you have any tips for building up that awareness?

Gregg Carb: Well I think that a lot of people do have a chronic problem with posture awareness, which is in part due to a lack of understanding of the normal shape of their spine, so taking that first step to better understand how your body is built is a good starting point to building your awareness. From that point forward, it's pretty much a matter of using simple reminders, such as a Post-it note, setting a timer, or using a computer program that reminds you to periodically check your posture, take a break, adjust your chair, or perform some simple stretches. On my website, which is posturepress.com, there are free downloadable items, such as a computer monitor placard that sticks to the top of the monitor screen and shows correct and incorrect illustrations of posture, and there's a weekly self-care record form that helps people track symptoms, stress, workload, and various movement techniques I recommend for activity breaks that people take during the day.

Rachel Salaman: Do you find that some people find it more comfortable to sit badly, and that if they change their posture and sit up properly, they actually find that they develop some pain. Does that ever happen?

Gregg Carb: I think people can get used to sitting incorrectly, but eventually, it's impossible for an incorrect sitting position not to accumulate damage focused in one area of the body or another, so they may think that they're relieving strain on one part of the body, but essentially what's happening is they're shifting that to another and instead of distributing the body's weight over a larger area, it's simply being concentrated to a smaller area and eventually, it must, you know, manifest in some problem in the area in that it's being concentrated. So, even though people sometimes like to slouch or slob and they resist a correct posture because they think it's more comfortable, in the very short term, for one area of the body it may feel more comfortable, but eventually, the damage will catch up to the parts that are, you know, bearing the greater strain.

Rachel Salaman: And by the same token, presumably once they get used to sitting properly, it won't feel so much of an effort?

Gregg Carb: If you do sit correctly, it really is no effort at all and the reason for that is because we're directing our upper bodyweight back into the seatback, which is what most people fail to do. So, even though you're not actually reclining, you're still allowing your weight to fall back into your seatback, so that it really takes no effort and then your thighs are on the bottom part of the seat and your feet are on a footrest or on the floor, so you've got a really great wide area of weight distribution and you have your upper bodyweight falling into the seatback, so it's a very relaxing and comfortable position.

Rachel Salaman: Now step eight is "Undoing damage with extension stretching" which you mentioned earlier. When should we be doing this stretching?

Gregg Carb: Well, the purpose of the extension stretching is to offset the inevitable forward rounding that occurs with sitting deskwork, and many everyday standing activities, such as cooking and cleaning. Remember that the connective soft tissues adapt to the position you're most often in, so to preserve a neutral posture, you have to stretch in extension to maintain some balance in tissue tension. There are two types of stretches to do. One is short term, for only ten seconds or so, just to take your muscles through a range of motion and this should be performed several times a day. The other is long term for about ten minutes continuous, which is required once per day to achieve a deeper stretch and lengthen the connective tissue.

Rachel Salaman: It is easy for you to describe these two types of extension stretching now?

Gregg Carb: Well, essentially, let me give you an example, the head, the neck, the arms and the shoulders will be extending backwards. The short term stretch can be done sitting or standing, such as, you know, leaning back over the seatback of your chair a bit, letting your head extend away and stretching your arms out with the palms up. But the long term stretch is then lying down, on your back, generally near the edge of a bed. It's important to understand that the long term stretch gives a unique benefit that can't be achieved through, you know, like, exercise or medication or support, even ergonomic devices or any other method. It's a time-dependent process. I should also mention that there are some medical conditions that would rarely prevent a person from performing this stretch, and those precautions are mentioned in the book and on the website.

Rachel Salaman: Well, you call step nine "Moving it, instead of losing it" what's your main message here?

Gregg Carb: Well, our bodies were made to be in motion and considering all the many muscles and joints we have, motion is absolutely necessary for things like circulation, digestion, and respiration. So if you don't move, you will lose your flexibility, strength and energy. And our need to move cannot be satisfied in one lump sum, we need to move on a periodic basis, all day long. The movements can be as simple as, you know, standing and then turning and tilting your body right and left. Maybe two or three times a day you need to do something somewhat more strenuous to increase your heart rate, like taking a flight of stairs or brisk walking. Of course, almost anything is better than just sitting there.

Rachel Salaman: So we should be getting up, moving, sitting back down again and then an hour later, doing that again?

Gregg Carb: Absolutely, you know, no matter how correct your posture is, you still need some movement, and I actually recommend maybe, you know, no longer than 30 minutes, and a person who is doing a heavy workload, they don't even have to leave their desk, this can be done just standing right in front of your desk, right where you are, but when you stand up, you know, physiologically you're changing things in your body. You're bearing weight, and then you can just do a light range of motion, just for 30 seconds or so. It's a small thing, but the small things add up, over a course of the day, to your benefit, and if you don't do those small things then the cumulative damage can also add up, so it's just a question of if you want to end the day with a benefit or with a deficit.

Rachel Salaman: Well as with all worthwhile endeavors, practice makes perfect, and this is step ten, "Practicing good posture". What's the best way to practice?

Gregg Carb: Well, the answer to that question is to maintain the normal shape of your spine, in all your rest and activity positions. Start by putting your attention on the places that you spend the most time, and for many people that's sitting at their desk, driving in their car or riding on the bus or train, and sleeping in bed. Those postures should be as neutral as possible and that will make the biggest difference. It's a good idea not to skimp on a good bed or a good chair because you'll probably spend the majority of your life in those two places. Also remember good posture practice means not sitting for too long at any one time, because even if the sitting posture's perfect, it's still sedentary.

Rachel Salaman: So if sitting is so bad for us, should we aim to stand more? I know some people have desks that can be raised to accommodate a standing position.

Gregg Carb: Well, sitting is only bad if you do it incorrectly or for too long, at any one time. Because so much of the work we do is computer-based these days, people tend to commute and travel a lot as well, so sitting is mostly unavoidable. So we need to learn to sit smarter so that sitting is supportive and comfortable and relaxing. I think that standing workstations are a valid alternative to sitting, although they can present some problems of their own, such as, you know, causing sore feet or varicose veins in the legs. So it's fine to alternate sitting in a supportive chair with other positions, such as a standing workstation, but for most people, it's not going to be practical to completely replace their chair with some other set up.

Rachel Salaman: But alternating might work?

Gregg Carb: Alternating is the way to go.

Rachel Salaman: What tips do you have for people who might want to start improving their posture today?

Gregg Carb: Well, first learn about your body and how your frame is held together. Put your attention on keeping your ribcage upright at all times when you're standing or sitting, and everything else will follow that. When sitting, always try to sit well back into the seatback of your chair, and avoid reclining, unless your head can recline as far back as the rest of your spine, and then it's okay. No matter how good your sitting posture is, try to avoid continuous sitting for more than 30 minutes at a time without standing and moving your body in some fashion. And take some time every day to stretch your body in extension, on a gym ball or a foam roller, or at least just let your body return to a neutral position by lying flat on your back on the floor with your palms facing up for about ten minutes each day. When we went back to one of the first questions that we started, it had to do with the normal shape of the spine, and I mentioned that the head and the ribcage and the pelvis, you know, should be aligned front to back and side to side, just one on top of the other, so when we lie flat on a surface, then – and without any pillows at all, then the head and the shoulders and the ribcage and the pelvis must be flat because they're the only parts essentially, that are touching, as you lie flat. So that at least assures that you're going to return to a neutral position in just doing that. Now because a lot of the deskwork we do tends to roll the palms down, computer typing, writing, using a mouse or the pointing device, tends to bring the palms down, so we like to lie with the arms just away from the side a little bit, but with the palms up, which rolls the shoulders and the arms outward a bit. The only modification that a person might want to make to this neutral flat position would be to put a small pillow or roll under their knees, just to create a little bit of greater comfort for the lower back.

Rachel Salaman: Dr Gregg Carb, thank you very much for joining me today.

Gregg Carb: It's been my pleasure, Rachel.

Rachel Salaman: The name of Gregg's book again, is The Science of Sitting Made Simple. He also has a very comprehensive website at www.posturepress.com. I'll be back next month with another Expert Interview. Until then, goodbye.