The office whether we like it or not is the place where most of us will while away a 1/3 of our lives whilst employed in an office.
Questions are often asked as to how sitting might help mitigate the worst excesses of sitting all day and whether buying highly expensive seating from bespoke shops advertising enhanced seating experiences may help reduce the potential problems that extended periods of seating may confer to the sitter.
In a series of a few articles I aim to take you on a seated journey to explore the anatomy of sitting and what it does to you, (not a pleasant journey).
Should you manage to sit comfortably at the end of the article(s), not only will you be healthier, and in less pain but you may also have saved yourself a lot of hard earned money by buying a chair that is both comfortable and reasonably priced.
Why Sitting too Much is Bad
So lets start with the cheerful stuff first:
- Sitting too long hurts the heart in many studies including one done on bus conductors (when we had them) and drivers. The drivers had twice the frequency of heart disease as those like the conductors who walked about.
- You are more prone to diabetes. It is not known exactly why, but the body whilst sitting seems to change its way it reacts to insulin the hormone that regulates your sugar level.
- You are more prone to DVT (Deep vein thrombosis), which in essence can kill you. The mechanism here is that your leg is flexed for prolonged periods and a clot can develop and travel towards your vital organs eg brain or heart.
- In a similar vein it can also cause varicose veins, again the prolonged sitting leads to increased pressure in the veins and if the valves which help contain the venous blood from flowing back stop working efficiently varicosities ensue.
- Osteoporosis is an added risk, from prolonged sitting bones aren’t getting forces through them which allow them to strengthen, which over time leads to a weakening of bone structure and makes people more prone to fractures.
- Sitting leads to increased disc pressure which increases the likelihood of disc problems such as herniations and prolapses. (More of this later)
- If I haven’t depressed you just yet, and as I get into the swing of warnings there is also the increase risk of cancer of the colon, endometrial and lung cancer.
- The final nail in the coffin is that sitting too long can shorten your life.
Now my mission is to very gently cheer you up.
Before this though lets just debunk some of the more common perceptions of what the overall problem with “research” into correct seating is:
Firstly when sitting people often have difficulty in telling which chair is the more comfortable whilst chairs have been graded into a hierarchy of ergonomic capabilities. Sitting in different chairs becomes indistinguishable because differences are difficult to perceive.
All spinal joints are attached by tendons and ligaments and via a complex of nerves via what is called a proprioceptive feedback (Cells in and around your joints convey back to the brain exactly where you are and at what angles which in turn relaxes and tenses different muscles to make you stable and not topple over.).
Joints are relatively insensitive to small angular changes as a result the spine does not reckognize so easily small changes in posture.
As humans though we do perceive comfort. When were not comfortable most of us are not happy. We therefore will always move the body into a position of maximum comfort.
In the end we it is comfort more than anything else which must drive our decision.
On this cliff-hanger I will add on this article next week to conclude the various options and what can be done both to extend your lives and help you sit more comfortably.
If you cant wait for the next episode you can contact me anytime and although I wont be able to give the plot away completely I will ensure a peaceful week of sitting.
hair users have difficulties distinguishing between chairs of different ergonomics quality. Many ergonomics features that are supposed to relieve discomfort in sitting are indistinguishable because they cannot be perceived. This is due to poor proprioceptive feedback from ligaments, joints and the spine. The joints are relatively insensitive to small changes in angle, and the spine cannot sense differences in pressure due to different body postures. Aesthetics features on the other hand, and features related to comfort and relaxation, are easier to perceive and differentiate. A study of ergonomics chairs verified that users could distinguish between parameters that relate to aesthetics and comfort, but had difficulty in distinguishing between ergonomics features. In the end aesthetics may be more important than ergonomics—at least to the customer who will be guided more by aesthetics than longer-term ergonomic factors.
Medical and ergonomic field studies indicate that bad standing and sitting postures are sometimes accompanied by pains in muscle and connective tissues of tendons, joint capsules and ligaments. There is evidence that such pains can become the symptoms of chronic diseases attributed to rheumatic disorders.
Recent orthopaedic research revealed that inadequate standing and sitting postures provoke excessive increases of intradiscal pressure. These orthopaedic findings, together with ergonomic investigations on sitting behaviour and somatic troubles, provide good bases for the construction of rest chairs and work seats.
The optimal seat would have an adjustable seat back incline of 100 from horizontal, a changeable depth of seat back to front edge of seat bottom, adjustable height, an adjustable seat bottom incline, firm (dense) foam in the seat bottom cushion, horizontally and vertically adjustable lumbar support, adjustable bilateral arm rests, adjustable head restraint with lordosis pad, seat shock absorbers to dampen frequencies in the 1 to 20 Hz range, and linear front-back travel of the seat enabling drivers of all sizes to reach the pedals. The lumbar support should be pulsating in depth to reduce static load