“Good posture is the most important way of preventing back pain” (ref. Back Care by Health Education Bureau)

When sitting with bad posture the spine adopts a forward “C” Shape.

C = Bad Posture

The figure on the left is bending forward in a “C” position, and this is the position most of the worlds population adopt when seated at a desk. Consider your own working position. You’ll find it’s precisely the one on the left.

Sitting in the “C” position puts tremendous pressure on the spine. This is due to a basic engineering principal which states that bending something stiff creates stress in the object being bent. The more the object is bent out of position the greater the stress.

Consider this analogy:

Hold the bottom of a wooden ruler in your right hand. Grasp the top with your left hand and bend the ruler. This causes stress in the ruler. The stress is released when you remove your left hand, resulting in the ruler springing back to its original position.

Now imagine your spine bending “ruler-like” over a desk. A similar but greater stress is progressively built up in your spine. The greatest stress is down in the lumbar spine where most back pain occurs.

Spinal Pressure

Swedish study, showing that the greatest pressure on the spine occurs when sitting in a bad position Pressure exerted on the discs of the spine changes dramatically from one body position to another. The diagram below, the result of a Swedish study, shows these changes.

The spinal lumber disc pressure is least while lying on your back (position 1), and greatest sitting forward (position 8). Does this look familiar?

Spinal System-S reduces the pressure in the lumbar spine from position 8 (250 kg/sq.cm.) to position 6 (125 kg/sq.cm) This is the minimum pressure possible in the seated position for the person used in the study.

Perfect Posture

Perfect posture Perfect Posture is that position of the seated spine when the pressure on the intervertebral discs is least. Every spine has its own unique shape. When this shape is preserved the posture is perfect. However, the human spine was not designed to be seated, and perfect posture is nearly impossible to attain for long periods. It must be supported. In engineering terms the spine is a vertical flexible column that becomes flawed when seated. It needs correct support, and this is precisely what Spinal System-S provides.

Problem Solving

When a problem is to be solved the first thing to do is determine the causes. Apply the most obvious cause and see if that works. If it doesn’t try the next one, and so on.

This principle, probably never taught in school, is a reflex action with most people. Until they experience back pain. Then the principle is ignored. All sorts of remedies are applied with no thought given to the primary one. Back pain should be tackled by first making sure the sitting posture is perfect. If after some time the pain persists, it means the cause is not posture related. Then by all means experiment further.

Good Posture

Cartoon of a person sitting with their spine in the proper position To get relief, or to prevent damaging your spine, you must take immediate steps to reduce your spinal pressure by sitting correctly with your spine in its natural curved “S” position. This is systematically achieved by:
Footrest

Use a footrest, or some old telephone directories about 4 inches high. This raises the height of your knees and effectively changes your centre of gravity backwards helping to improve your posture.

Sit close to Desk

Sit as close to the desk as possible. This will counteract your old habit of bending forward over the desk.

Sitting

When working for long periods it is essential that your back be supported from the lumber region to at least the shoulder blades. The chair should be designed to support the whole spine right up to your neck. Naturally when you look down at your work you will lose contact slightly with the neck support. Ideally you should have a small lectern on the desk top. This will allow you to work with total spinal support.

For more information visit The Back Shop or email us at info@back-shop.com.

C.C. (Colm Campbell): I would advise extreme caution. The success rate is extremely low. The latest information on low back pain, published in the August 1998 edition of Scientific American, and written by Dr Richard Dayo of the University of Washington says “the actual proportion of all back sufferers who are surgical candidates is only about 2 %”.

Customer: So what can you do?

C.C.: I eliminate the main cause of back pain.

Customer: What’s that?

C.C.: Bad posture.

C.C. (Colm Campbell): I’ve designed this piece of equipment for measuring spinal curvature.

C.C.: I put the person sitting in the measuring chair and gently push the spine from it’s original position, as indicated by the dotted line, into the correct sitting position by means of the sliding bars. I make a cardboard template of the spine, in this perfect posture position, and from this the back of the chair is made to precisely conform to the person’s back shape. The measuring chair also gives me the information to make the arm height, depth, height, and width of seat to exactly match the person’s physical specifications.

Customer: What’s this perfect posture?

C.C.: I define perfect posture as that position which puts the least stress on the spine.

Customer: Why do you have to measure? Why can’t one chair do for all?

C.C: Every spine has its own S shape which is unique to it. The shape of a human spine is as unique as a fingerprint. Even people of the same size and build have different shaped spines.

Colm Campbell: Take a wooden ruler and bend it. When it’s released it whips back into position so fast you can hardly see it. The reason is that when something rigid is bent stress is built up along its length, and releasing it releases the stress. The stress is greatest down low where it is held. If I continue to bend the ruler it will break exactly in this position. It’s exactly the same with the spine. Sitting with bad posture means the spine is slumped into a forward “C” position and this puts enormous stress on the discs, particularly on the lumbar ones. This is where most back problems occur.

I’ll give you a simple slogan. It should be nailed on the notice board of every office around the world, and domestically should replace the “home sweet home” slogan. If people would always bear it in mind it would greatly reduce the incidence of back pain. It’s this:
“C” = Bad Posture; “S” = Perfect Posture

Bad Posture - 'C shape'

Perfect Posture "S" shape

C.C. (Colm Campbell): If you follow me I’ll show you the way you and ninety nine percent of people sit at an office desk. It’s the reason why the vast majority end up with back pain.

(C.C. walks over to a desk, sits on an office chair, and simulates somebody crouching over a keyboard.)

C.C.: The C position. Does this look familiar? (The customer nods again)

C.C.: As you can see I’m bent over the desk like a bent wooden ruler. This puts huge pressure on my lumbar spine.

C.C.: Let’s examine the neck.

(C.C. sits well back into the chair with his spine supported right up to the nape of his neck, elbows perfectly supported, arms gently sloping downwards, as he pretends to key)

C.C.: I’m now sitting with perfect posture. The S position.

Customer: How do you know that?

C.C.: Because the chair was made for me using Spinal System-S. As my head is resting on the headrest the stress on my neck is very low.

(C.C. again bends over the desk)

C.C.: The stress on my neck is now huge. Do you know why?

Customer: Because you’re bent over the desk.

C.C.: Yes. But I’ll demonstrate the reason. Hold this upright with the thumb and index finger.

(C. C. gives the customer a hard backed book. The customer does as requested.)

C.C.: Now bend your arm slowly forward keeping the book in the same plane. (When the book reaches an angle of about forty five degrees from the vertical the customer has difficulty holding on to it.)

C.C.: The reason you are losing control is because a moment ago the weight was acting straight down your arm. Now the weight is still acting downwards but it’s displaced from the fulcrum, the place where you’re holding it, by about eight inches. This causes a huge leverage effect, the weight multiplied by eight inches. It’s the same with your head. The weight of the book is very low, less than a pound. But your head is a large percentage of your overall body weight. The average weight of the human head is around 14 pounds. When the head is vertically over the spine the stress is at a minimum. But when you bend forward the weight of your head multiplied by the distance from your neck results in enormous stress in your neck. And a neck pain can be a lot more difficult to cure than one in the lumbar spine.

Customer: Why is this?

C.C.: The lumbar discs are massive in comparison with the cervical. And the cervical are moving all the time. They get little chance to rest.

Richmond chair

Customer: Are Armrests useful in preventing back pain?

C.C. (Colm Campbell): Armrests are extremely important. For two reasons. Firstly, when you are sitting with your elbows properly supported you are taking a considerable amount of weight off your spine and transferring it down your arms. Secondly, in an office situation, when you are keying without armrests, both of your arms are suspended in space and this puts stress on your neck. Keying with proper armrests prevents this stress.

C.C. (Colm Campbell): No. I can’t guarantee anything.

Customer: But will the S position get rid of my pain?

C.C.: When the chair is used correctly in the majority of cases the result is the relief of pain.

Customer: What do you mean by correctly?

C.C.: You must sit with your bottom right back in the chair and with your spine supported right up to your neck, and your elbows resting on the armrests. And, oh yes, I forgot to mention, working at an office desk, unless you are extremely tall, use a footrest.

C.C. (Colm Campbell): The height of the average desk is around 27 inches. This means a person of average height must sit quite high in order to work with arms gently sloping downwards to the desk or keyboard. This means sitting with knees considerably below the hips. The result of this is a tendency for the lower body to drag the upper body forward into a C position. Using a footrest raises the knees and tilts the person backwards to a better sitting position.

Customer: What height of footrest should I use?

C.C.: You’re average height. I’d recommend a four inch high one. A taller person would need something in the region of two inches. The guiding rule is you should be sitting with your knees in line with your hips or slightly above. There are exceptions of course.

Customer: Like what?

C.C.: Many people have great difficulty in rising from the sitting to the standing position. So sitting height is of the utmost importance. The higher a person sits the easier it is to rise. But this means their knees would be lower than their hips. People with hip problems are a good example.

Customer: Somebody told me you should always sit with your knees way above your hips. Many cars are like this.

C.C.: Sitting with knees too far above the hips reduces the angle between the spine and thighs. Anything below ninety degrees puts tremendous stress on the lower spine and can tweak the sciatic resulting in pain which, in my own personal experience, is even greater than back pain. You mentioned car seats. They are well engineered with all sorts of clever adjustments. But they totally neglect the seat’s main function. To support the spine in good posture. Almost all car seats appear to be designed to make sure drivers sit in the C position. And the whole thing is compounded when using the clutch and brake. Pressing on the pedals transmits large forces up the legs to the lumbar spine.

C.C. (Colm Campbell): Sitting with knees too far above the hips reduces the angle between the spine and thighs. Anything below ninety degrees puts tremendous stress on the lower spine and can tweak the sciatic resulting in pain which, in my own personal experience, is even greater than back pain. You mentioned car seats. They are well engineered with all sorts of clever adjustments. But they totally neglect the seat’s main function. To support the spine in good posture. Almost all car seats appear to be designed to make sure drivers sit in the C position. And the whole thing is compounded when using the clutch and brake. Pressing on the pedals transmits large forces up the legs to the lumbar spine.

C.C. (Colm Campbell): Yes. A car seat mould

C.C.: It’s a custom tailored back support that straps around the back of the existing car seat and is made using Spinal System-S. It converts the average badly designed C seat into one that’s an S.

Customer: Why call it a mould.

C.C.: A mould is something that preserves a shape.

Customer: The S shape.

C.C. Exactly

C.C. (Colm Campbell): Quite a number of my customers are medical doctors. A lot of them refer patients, as do the alternative medical people like chiropractors, osteopaths, and acupuncturists. But they all try out their own particular expertise before applying logic.

Customer: What do you mean?

C.C.: Look at it like this. If you have a problem, the first step in solving it is to find the causes. You then apply the most obvious one and see if that works. If it doesn’t you try the next one, and so on. Would you agree?

Customer: Yep. I’d go along with that.

C.C.: My philosophy is that back pain, not directly caused by an accident, should be tackled first by making sure the sitting posture is correct. If after some time the pain persists, it means the cause may not be posture related. Then by all means investigate further. This approach is non invasive.

Customer:

C.C. (Colm Campbell): We do a range of chairs. The ones you see in front of you are some of the range. If you want a design we are not carrying give us a photo or a sketch and we’ll make it for you.

C.C. (Colm Campbell): The best type of chair, particularly for you with a neck problem, is a recliner. It’s really three chairs in one. You probably sit upright then, like the majority of men, after a period of time you get uneasy and start shifting from one buttock to the next until eventually your bottom moves forward in the seat and away from any support in your lumbar spine. This position puts great stress on your neck.

Customer: How the hell do you know that?

C.C.: I’ve been observing this for many years. Most women can sit for several hours at a time without moving. Men start fidgeting about after a much shorter period.

Customer: Why?

C.C.: I think women have better designed undercarriages. Anyway, when you get the squirming urge, in a recliner you just simply tilt the chair back. This relieves the uneasy feeling by transferring pressure to a different part of your body. And so on.

Customer: Yeah. But hang on. By doing this isn’t the S tilted to a different angle?

C.C.: Without sounding condescending, that’s a very intelligent question. You’re absolutely right. But look at the Swedish diagram again. The more you go to a reclining position the less the stress becomes. With the recliners we make, as you move from one position to the next, the spine and thighs are fixed. They don’t move relative to each other. So no matter how you sit you are always in the S position.

C.C. (Colm Campbell): It depends on what you are doing. An office chair would be at five degrees back from the vertical (95 degrees) because it’s a working chair. I wouldn’t make you a chair for the home at this rake. It’s too upright. The tendency would be for you to slump forward into the dreaded C position. The average home chair would be 10 degrees back from the vertical (100 degrees). There are exceptions of course. I recently made an office chair for a Professor of Anatomy. She can only sit without pain when the rake is at 85 (five degrees forward of the vertical).

Read more about the interview here on RTE website

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