Backache? It does not matter how you sit or on what you sit. What does matter to your spine is how long you sit.
Potential breakdown of spinal components start after 6 hours unless your chair is bio-mechanically friendly to them. This work is intended to explore the bio-mechanical (ergonomic) factors that may determine spinal pathology and lead to backache (Low Back Pain. LBP). And derive some answers.
Sitting on a log, a tree stump, an old dining room chair or a conventional office chair does not have a great effect on your back. It is on prolonged sitting that the bio-mechanics (ergonomics) affect spinal components. How long? Research suggests six hours or more which is common in the present work environment.
NAVIGATION through the website
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The effects of Upright sitting. The results
The evidence identifies the adverse factors which occur with conventional prolonged mid-upright sitting. Described under ☛ Biomechanics→. It results in flexion of the lower lumbar joints, which can cause spinal pathology. These include permanent stretching of the posterior spinal elements and a shift backwards of the IV disc contents (Smith F, 2007→). towards pain sensitive structures that can account for backache & series spinal conditions. The upright seated posture.
A simple illustration of the effect of sitting upright is shown here :-
The obvious, and perhaps only, solution was for prolonged work to be performed in a chair that has a stable, correctly supported, supine reclined mode. Shown here is the Okamura ‘Atlas’ chair. ☛ Atlas→
Other partial solutions include ☛ Pelvic support→,
The only full solution is :-
This is the big story derived from examining the bio-mechanical evidence, identifying the factors which can result in spinal breakdown on upright sitting and finally devising a concept for office work-chair design that avoids these adverse factors. The conclusion was theoretical but was later validated and confirmed by a new technology ‘positional MRI’ (pMRI). A fully compliant 2T chair is ergonomically optimised (and optimally comfortable). Anything less should be unacceptable for prolonged use.
The 2T concept addresses all the ergonomic factors that ensure a sitting position that is the least likely to perpetuate, or result in, backache and other spinal conditions. It also includes the necessary requirements to make this a user-friendly practical work-chair. Comfort is also thereby maximised. ☛A Full solution→
Perception & Reality. Familiarity bias
Western people have sat in an upright chair since childhood resulting in Familiarity bias. They have been indoctrinated that mid upright sitting is ergonomically ‘correct’. Chair designers have ensured comfort. Therefore it is not surprising that most people perceive this as correct and desirable. It will take time to change this misconceived perception. First chairs designed on bio-mechanically correct lines must be manufactured. Their advantages need to be explained. I have noticed that people who are liable to backache immediately recognise the advantages and are likely to be the first to create a demand. The newer generation is already more open to fresh ideas and also take quickly to a 2T design.. Insurance is already begining to take an interest (personal communication). HAS