Category Archives: HOME. Backache and chairs

Back pain and chairs. The biomechanical (ergonomic) factors resulting in backache (LBP) and the requirements for remediation.

Improving an upright chair.

 

OK.  So you use a chair and are liable to backache.  All this is very confusing and so what do you do?   I am no longer in the business of giving advice to patients and organisations.  However my interest in optimising chair design might allow me to offer some tips.

If you have an expensive, top range chair, examine the section on how some of these relate to the 2T concept and could be upgraded (so far, largely ignored) by manufacturers.  This may help you modify your own chair.

Chair remediation.

Only a forward tilted seat (FTS) or the incorporation of ‘Iliac’ support allows a chair of this type to be considered as a semi-partial solution to the adverse effects of mid-upright sitting. It is therefore essential that the support should be of the right type and directed to the right place.   Check with the relevant posts. See ⟵The 2 modes 

Chair remediation. Pelvic (Iliac) support.

Chair remediation

See Pelvic support

Chair remediation. Forward Tilted Seat.

Screen Shot 2013-10-17 at 14.25.36This is an alternative and the preferred option for the 2Tilt concept.

See Forward Tilted Seat

 

A variation of these designs is to have an antero-posterior convex seat surface, the Ischial ‘Off Load’ system.     ⟵Off-load system 

Chair remediation. Possible adjustment.

A good chair can be modified to approach the advantages of the 2T CONCEPT (see ‘A complete solution’).

  • Disable the adjustment that allows the pelvic support to be above 20 cm above the seat (?Chewing gum)    (see ‘Lumbar, pelvic/iliac support’)
  • Arrange for the adjustment control to allow easy back & forward reclination movement.  Make the chair a 2T system – either reclined or forward but not intermediate.
  • Intermediate ranges should be unstable.   They can be used as a rocking chair or as  therapeutic exercise following an acute episode of backache/lumbago.
  • In the upright mode the seat can be either tilted forward (see ‘The forward tilted seat) or arranged to take advantage of the pelvic support providing this is correctly modelled.
  • Apart from chair height and head/foot-rest, adjustments should be set accordingly and then ignored or fixed.
  • And let me know how well it works!

If your chair is more ordinary you may be lucky and have one that has reasonable iliac support or a forward tilted seat.  If you are buying, a back shop can show a number of models and advise but be aware that they are trying to sell you something and tend to feed you the manufacturers hype.

Chair remediation.  If all fails.

If your chair is really basic you may need some widgets. Possibilities are

  • A wedged cushion on the seat which helps approximate to a FTS.
  • A backrest cushion that gives iliac support.  Have a good look at the section here on iliac support that must not be higher than 20 cm above the seat and approximates as near as possible to the original Gorman model.
    • My patients loved the ‘PostureRight’ cushion which was designed by my old St Thomas’ colleague, Dr Bernard Watkins.
    • Various lumbar ‘Rolls’ are OK if correctly placed.
    • I have a cheap (£1) and cheerful wire & net model which works moderately well.

Good Luck!

There is plenty of well intentioned advice to be found on the web.  But please read this first (Sorry, hard work, I know) so that you can distinguish the  rarely well informed from misinformation  and some that is frankly laughable.

The best that I have seen is from Posturite in 4 easy diagrams.   http://www.posturite.co.uk/art-of-sitting     Obviously written by someone who is well informed.

The Hermann Miller account from being almost laughable is now good, probably as a result of being advised by Andersson, the Swedish scientist.

 

Next see  ☛ →

Managing the Ergonomics

Managing the Ergonomics of Office Seating

 by John Jukes                       The Source Publishing Company Limited 

Ergonomics expert John Jukes asks is the Sit/Stand desk the answer to aches and pains in the office?

Research done by Dr Henry Sanford see, Orthopaedic Consultant at the Cromwell Hospital adds another dimension to the problem of ergonomic comfort in the office. Sitting in a semi reclined position at 45 degrees reduces the gravitational loading on the spine by 50%. This is similar to the astronaut position, which permits working under heavy G forces. A suitable headrest and positioning of keyboard and VDU screen makes this a perfectly practical working position without inducing sleep. Many programmers, CAD users, control room engineers and tall people are seen to adopt this position using an ordinary chair when  working for long periods – perching the tail on the front edge of the chair with their shoulder on the back and the legs out straight.

Sit/stand desks and pelvic support semi recline seating  in the UK have yet to become part of the normal office landscape. When they do there will be several million office workers that will be grateful to be free from daily debilitating pain.

See OFFICE HEALTH, Stress & Ergonomics

He wrote

Dr Henry Sanford MA. MB. B Chir. (Cantab) D  Phys Med. (Lond) is a well known Consultant Orthopaedic Physician in London and Associate Consultant to the Department of Rheumatology, St Thomas’s Hospital, SE1.  Earlier he worked at St Thomas’s with Dr J H Cyriax who is regarded as the ‘Father’ of  Orthopaedic (or Musculo-skeletal) Medicine after following 2 years in the army finishing as a Captain in the RAMC.

He was a founder member of the Society of Orthopaedic Medicine (SOM), the British Society of Musculo-skeletal Medicine (BIMM) and was Chairman of the Cyriax Organisation..  He has run courses and lectured internationally                                                              John Jukes – 30/07/2001

 

HAS19.07.34HAS & M19.08.43                  

 

 

 

 

HAS in BAOR,1954

and with daughter, Marietta, in Cambridge, 2005.

Prevalence and economic cost of LBP.

 The increasing backache prevalence seems to be a genuine phenomenon of the 20th/21st centuries in Western societies at the same time as the increase in sedentary occupations and lack of exercise ..  The scale of mechanical  Low Back Pain (LBP) problems is confirmed by many studies from many countries.

Screen Shot 2018-06-11 at 21.35.22There has been a slight drop in prevalence in the last few years.  Perhaps it is presumptuous to suggest that this may be due to improved seating following my views put forward  in 1998 although a full 2T chair is not yet in the market.

LBP is the most common health problem for British workers. The Clinical Standards Advisory Group (Waddell), in 1994, in a study of the  backache prevalence and it’s cost  estimated that, since 1978 the  annual loss of working days due to low back pain had increased 200% to 150 million days.    A study in Manchester (Croft 1998) showed that 50% of women aged 45-50 claimed to have suffered from backache in the previous  month.  A prospective UK trial (Croft 1999) showed a 36% increase in prevalence of backache and incidence rate in 1 year.    Since then there has been a slight drop possibly due to better designed chairs, many of which are slowly approaching my views.

Back pain is also one of the most costly conditions for which an economic analysis has been carried out in the UK and this is in line with findings in other countries. It is estimated that the direct health care cost of back pain in 1998 to be £1632 million.  Approximately 35% of this cost is most likely paid for directly by patients. With respect to the distribution of cost across different providers, 37% relates to care provided by physiotherapists and allied specialists, 31% is incurred in the hospital sector, 14% relates to primary care, 7% to medication, 6% to community care and 5% to radiology and imaging used for investigation purposes. However, the direct cost of back pain is insignificant compared to the cost of informal care and the production losses related to it, which total £10668 million.  (Maniadakis N, Gray A. 2001)   (Maniadakis N, Gray A. The economic burden of back pain in the UK. Pain. 2000 Jan;84(1):95-103.)

The Centre for Health Economics (CHE) showed a cost to the UK NHS of £265.3 billion – £382.7 billion in 1992-93.  https://www.york.ac.uk/che/pdf/DP129.pdf

The Work Foundation estimates that employees suffering from bone and joint pain cost the EU’s economies 240bn euros (£200bn) each year.  “Sitting is the new smoking,” explains Prof Steve Bevan, director of the Centre for Workforce Effectiveness at the Work Foundation.  “The more sedentary you are the worse it is for your health.”   The Lancet, published a study in 2012, which found that musculoskeletal conditions were the second greatest cause of disability in the world, affecting over 1.7 billion people worldwide.  “I describe suffering from musculoskeletal disorders as being like a Ferrari without wheels,” says Prof Woolf, who is also the chair of Bone and Joint Decade. “If you don’t have mobility and dexterity, it doesn’t matter how healthy the rest of your body is.”

In the United States About 100 million workdays are lost annually  (Johanning 2000).  Insurance figures show that 82% of US office workers complain of LBP (personal communication 2012 HAS),   Lower back pain’s economic impact is shown to be the number one reason for individuals under the age of 45 to limit their activity, second highest complaint seen in physician’s offices, fifth most common requirement for hospitalization, and the third leading cause for surgery.  (Health and Safety Executive‘s Better Backs campaign.https://en.wikipedia.org/wiki/Health_and_Safety_Executive).

The UK DoH (Dept. of Health, Dept of Children, Schools & Families.) issued an authorative report on ‘Sedentary Behaviour and Obesity: Review of the Current Scientific Evidence’. See  https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/213745/dh_128225.pdf

“In conclusion, upper-extremity MSS (musculoskeletal symptoms) affected more than half of the study participants who used a computer for more than 15 hr/week (Gerr et al American Journal of Industrial Medicine 41:221-235,2002).

. The actual increase of mechanical spinal pathology and backache prevalence seems to be a genuine phenomenon of the 20th century and is rising exponentially (Hemingway 1997) with the increase in sedentary occupations.”Mankind has progressed from Homo sapiens to ‘Homo sedans” (Mandal).

(Prevalence = the number of existing cases overall.   Incidence = the number of new cases in a given time.)

Next ☛BACKACHE? For users and patients (only)

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