How can you produce your best work if you are sitting in an uncomfortable chair?
Do you get niggling pains in you lower back? your neck? Or your shoulders?
Maybe its time to look more carefully at the chair you are sitting on. How is it designed?
For several hundred years there was no change in the basic design of the conventional chair. The seat was set at a 90 degree angle to the backrest – an ‘L’ shape.
Some of the early additions to the standard chair for use in offices were:-
A swivel action which allowed the user to swing around – maybe the designer was fascinated with merry-go-rounds!
Next there was the wonderful up and down action of the hydraulic lift. People of short stature had to come up with a footrest of some sort if they wanted to be relatively
comfortable at work. A common drawback of these devices, at least in the early days, was that the gas leaked from the system and then the seat “let you down”.
A further addition to the “office chair” was the provision of armrests.
It was not until the 1970s that a major change to the basic ‘L’ shape of the office chair
came about through the studies and research of a Dr. A.C. Mandal in Denmark who was one of the pioneers in proposing the benefits of a forward-sloping seat. Dr. Mandal had
found that the only way he could remain seated without incurring backpain was to lean forward on the front legs of his chair. He also observed that many school children did the same thing when trying to ease back pain brought on by poorly designed school furniture.
Mandal recommended that the seat pan should slope forward by 15°. When we take up this position our lumbar spine does not need to flatten out to assume the seated posture
and our hips and trunk are at the optimum position of balance for the muscles.
By tilting your seat forward you alter your centre of gravity from behind the sitting bones (ischial tuberosity) to directly above them. As a result your muscles do not have to tense up or contract to maintain an erect posture. At the same time the lumbar curve ( or lordosis) is restored and pressure on your discs is reduced.
Some of the more common objections to early versions of the sloping seat were:-
You tended to slide forward.
Too much weight was placed on the feet.
Your clothes tended to 'ruck up'.
Balans Chair:
The Balans was one of the first forward-sloping chairs in mass production to incorporate Mandal's suggestions - using a knee rest to prevent slipping forward.
Most of the weight is taken on the knees and while this reduces pressure on the discs, the muscles had to work harder to maintain an erect posture since there is no backrest. As your muscles become tired there is a natural tendency to slump. In addition to these problems your knees and shins can become quite sore after a time
since there is no provision for changing the knee position. Getting in and out of the chair is somewhat difficult because of interference from the central pillar.
Despite the various drawbacks mentioned, however, many thousands of these chairs were sold because of the obvious relief given to the discs through the forward-sloping seat
taking pressure off the spine.
Kneelsit Balance Chair
When you allow the seat pan to tilt forward your pelvis rotates forward, this posture produces the least amount of stress on muscles, tendons and discs, since your spine is
correctly aligned.
It also pulls the chest out, increases lung capacity and makes breathing easier as well as improving the working of the heart and blood circulation; it also allows you an open
abdomen, which aids digestion.
When your pelvis is tilted forward your lumbar spine curves naturally and the rest of your spine follows. This is the ideal posture when working upright - as at a computer. When
you have a backrest - as in the Kneelsit chair - this backward tilt can also be used to relax the spine and take pressure off your disks and muscles, for example when you are reading or just chatting.
The real secret, however, to maintaining a healthy spine is to have a chair which allows free-flowing, natural movement between both forward and backward tilts. This sets up a
continuous "pumping action" which feeds and nourishes the cells of your spinal discs, exercises your back muscles and allows you to sit for hours on end with very little
discomfort.
Author Resource:-
About the Author
Gregory J. Usher B.Ec., Dip.Ed., F.A.I.I., M.Psych. is the designer and Inventor of a unique patented ergonomic computer chair named Kneelsit The Chair for Life which has been selling via the Internet since 1996. To learn more about this unusual chair you may like to visit the author's website.
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