An account of the bio-mechanic (ergonomic) factors, associated with prolonged sitting, accounting for mechanical spinal pathology (Backache, LBP, IVDisc pathology, CTD) and options for their remediation.
- Although intended as a resource for the design of work chairs, it represents some essential reading for designers of ergonomic chairs and manufacturersof retail office chairs if they wish to improve the ‘ergonomics’ of their models with overwhelming health selling points.
- Office managers should consult this blog as a resource. It is also very relevant to Interior designers and architects involved with office design and not forgetting the ‘end user’ who has the ultimate benefit .
The scientific evidence identified adverse effects which occur with conventional prolonged mid-upright sitting. The big story here, however, is that it was found that a reclined mode is the only position that avoids all the adverse effects of conventional prolonged upright sitting. For a reclined office work-chair to be practical a number of requirements are essential. These have been covered in the The 2 TILT CONCEPT (Now designated 3M & 4M) which was tested for practicality in the Cambridge MfI department. Although originally considered outlandish, recently design is now moving in this direction. The FUTURE is GOING THE 2T (4M) WAY→
The Layout Arrangement of this work.
For some readers this study was too large and diffuse. It is now divided into subdivisions.
This is indicated in the top menu↑. All post are shown in the menu on the right→ .
Specialists will prefer to jump directly to their page of interest using the Right menu→.
For an overview of contents…..
Designers are the intended readers and, apart from some duplication, are advised to read the whole work. This includes a large body of research and background, on spinal bio-mechanics.
- For DESIGNERS →
- MANUFACTURE of ergonomic chairs→
- For ARCHITECTS. ‘Coolness’ is the word.→
- & Office managers and include points on impact, implications and uptake For DESIGNERS & architects→
Manufacturers can be reassured that feasibility indicates that existing components can be used , avoiding the expense of retooling, while preserving their brand image. Prospective manufacturers can be helped to leap ahead of the field, ☛ →
New ideas can create both threats and opportunities , once both familiarity and normalcy biases are overcome. Creative disruption works.
Topics and some relevant subjects
- Anatomy includes a number of detailed studies of the more relevant component parts and an account of the paleoanthropology which resulted in the vulnerability of the lumbo-sacral junction. ☛ Spinal Anatomy→
- Biomechanics in relation to sitting postures. ☛ Spinal biomechanics→.
- How did we arrive here? ☛ Paleo Anthropology →
- In addition,The way we sit now, further explores present sitting including the comments (☛Why? Mandal explains…→), Gorman and others. Comparisons are made with various existing chairs (☛How do they measure up?→).
- Remediation describes various measures that have been taken to improve the ergonomics and their further evolution ☛The 2Tilt concept, the ultimate remediation →
- The office environment (☛Office→), it’s relation to physiological and psycho-social stress, ergonomics and remediation, the deskless chair and desk/chair interface.
For New offices ‘Coolness’ is the word to excite media interest for both the company and the Architect/Designer. Most firms aspire to project this cutting edge image. A 2T chair, or the derived 4M workstation, answers this exactly and in addition reduces LBP and increases productivity by lessened morbidity and stress. Also see ☛ PRODUCTIVITY AND WORKPLACE STRESSORS→(Article published in EurOhs, European Occupational Health and Safety Journal, Dec 2002.by Dr HA Sanford)
Allows an alternative view to the usual hype, often laughably misguided, from manufacturers,
And not forgetting the interest of all chair users ……
Also of LIKELY INTEREST to a general reader
Backache & chairs. A number of systems are described. Spinal bio-mechanics dictates that prolonged sitting should be performed in a reclined position with frequent change of posture. For a full remediation a number of requirements are essential. To be effective these are detailed in the 2 Tilt (2T) concept.
- Reduction of axial loading (Disc compression) →
- Avoid backward tilting of the pelvis →
- Ensure disc nutrition by pressure changes with movement →
Systems in use at present, See ☛ Remediation→
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, commonly used partial solutions include ☛ Pelvic support→,
- Incorporating movement, ☛ Dynamic seating→
A full remediation, the 2Tilt Concept, is suggested. See ☛ 2T concept→
Combining these requirements can be difficult to achieve but is possible in a suitably supported reclined mode at 40-45° which conforms to spinal morphology (configuration). This alone is impractical as a work position unless a number of secondary requirements are incorporated to make this simple concept suitable and practical for a work chair.
- A reclined mode for prolonged work ☛2T reclined mode→
- An upright mode required for certain jobs. ☛2T Upright mode→
- An unstable intermediate mode to enable a quick, easy transition between the 2T modes. ☛2T transition mode→ ☛ dynamic seating→ With the recognition that the transition movement has physiological advantages, this has been upgraded to a ‘mode’. The 2T now becomes a triple-mode (3M) concept.
- A sit/stand facility can be incorporated to become a 4M version. ☛Sit/Stand→
Compared to people who sit the least, those who spend most time in a chair have a 112 % higher risk of developing diabetes, a 147% higher risk of suffering “cardiovascular events” such as strokes and a 49%t increased risk of death from any cause. (http://www.telegraph.co.uk/wellbeing/fitness/sitting-disease-is-killing-us-and-exercise-doesnt-help/) Alarming but not entirely an effect of the bio-mechanics and not examined here. However some posts are relevant.
- OFFICE STRESS & Backache→
- ☛ Jukes. Managing the Ergonomics →
- ☛ PRODUCTIVITY AND WORKPLACE STRESSORS→ (Article published in EurOhs, European Occupational Health and Safety Journal, Dec 2002.by Dr HA Sanford)
- ☛ HAS, on ☛ Office health (& RSI)→ Only a lighthearted account.
- ☛ The OFFICE 2 Tilt chair →
- ☛ 4M OFFICE WORK-STATION→
- ☛ SLEEP & productivity