Ergonomics – What Works?

1. Ergonomics – What Works? Dr Richard Graveling FIEHF Principal Ergonomics Consultant IOM, Edinburgh

2. Ergonomics – What Works? • Brief overview of Ergonomics • Comments on two Cochrane reviews • Exploration of what works in Ergonomics

3. Ergonomics – What Works? Brief overview of ergonomics • What ergonomics isn’t!

4. Ergonomics – What Works? Brief overview of ergonomics • There is a lot more to ergonomics than office chairs (and computers). • Ergonomics is about designing for people, wherever they interact with other people, products, systems or processes.

5. Ergonomics – What Works? Brief overview of ergonomics • The scientific discipline concerned with the understanding of interactions among human and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimise human well-being and overall system performance. (ISO 26800)

6. Ergonomics – What Works? Brief overview of ergonomics • When a pilot misunderstands a poorly designed control and a plane crashes into the Atlantic – that’s ergonomics. • When systems don’t prevent a patient from being given ten times the safe dose - that’s ergonomics. • When a catalogue of design, system and human mistakes result in the worst ever offshore oil disaster – much of that is ergonomics.

7. Ergonomics – What Works? Two Cochran reviews: • Hoe et al (2012) Ergonomic design and training for preventing work-related musculoskeletal disorders of the upper limb and neck in adults. • Verhagenet al (2013) Conservative interventions for treating work-related complaints of the arm, neck or shoulder in adults.

8. Ergonomics – What Works? Two Cochran reviews: • Few, if any of the interventions appeared to attempt to relate the nature of the problem to the nature of the disorder. • For example, one review finding was for moderate evidence that providing a different mouse didn’t prevent neck/shoulder disorders. Why would you expect it to?

9. Ergonomics – What Works? Other evidence for prevention: • There are a number of case studies in the literature – but they don’t meet the rigours of reviews such as Cochrane due to no control group, no blinding, etc.

10. Ergonomics – What Works? Other evidence for prevention: • For example, Tesh (2014) identified a problem with the design of a medical equipment production process. • A focussed intervention produced positive benefits in a reduction in the incidence of MSDs amongst the workforce and a financial payback time within less than two years.

11. Ergonomics – What Works? Other evidence for prevention: Make the punishment fit the crime: • In a similar vein, Anema et al (2004) reported on a study of RTW interventions in sufferers of chronic LBP. • The interventions weren’t the same in each case – but were tailored to the needs of the individual. • The outcome was a significant reduction in sickness absence.

12. Ergonomics – What Works? Make the punishment fit the crime: • Not all MSDs are caused by work. • Intervention must relate to nature of injury and understanding of probable causal mechanism. • For example, where is the value in providing new seats for sewing machine operators suffering from neck and shoulder problems (as was reported in one ineffective study)?

13. Ergonomics – What Works? Problems stem from prolonged neck flexion and/or shoulder elevation • Any solution must address these sources – modifying the ‘offending’ posture.

14. Ergonomics – What Works? Why fixate on this? When faced with this?

15. Ergonomics – What Works? What does work? • Understand aetiology • Observe • Apply ergonomic principles

16. Ergonomics – What Works? Understand aetiology: • Shoulder impingement reduces blood flow – both mechanically and hydrostatically.

17. Ergonomics – What Works? Observe

18. Ergonomics – What Works? Provided new tool which was a more appropriate shape.

19. Ergonomics – What Works? Understand aetiology: • Wrist flexion/extension increases pressure in carpal tunnel (now part of PD A12)

20. Ergonomics – What Works? Understand aetiology: • Gripping (and lifting) increases pressure in carpal tunnel (not part of PD A12) From: Rempel et al, 1994

21. Ergonomics – What Works? Understand aetiology: • Work with computer keyboard or mouse can increase carpal tunnel pressure. From: Rempel et al, 1994

22. Ergonomics – What Works? Understand aetiology: • Epidemiology suggests relationship between CTS symptoms and computer work NOT causal. Supported by pressure studies which suggest greater pressure required for vascular effects in nerve.

23. Ergonomics – What Works? Observe: Provocation not causation – but still need to address. Make sure mouse fits hand and enables a straight wrist posture

24. Ergonomics – What Works? Different keyboard or mouse can be helpful – if it reduces gripping (mouse) or improves wrist posture when mousing or keying.

25. Ergonomics – What Works? Different keyboard or mouse can be helpful – if it reduces gripping (mouse) or improves wrist posture when mousing or keying.

26. Ergonomics – What Works? Observe

27. Ergonomics – What Works? Observe: How do we deal with these?

28. Ergonomics – What Works? Apply ergonomic principles: • The human body is designed for movement. • There is a growing body of evidence that the absence of movement plays a significant role in the causation of (office) MSDs. • The effects of lack of movement are exacerbated by (relatively) high muscle forces. • The further away a joint angle is from neutral – the greater the potential strain.

29. Ergonomics – What Works? Keep moving?

30. Ergonomics – What Works? Questions or comments? (thanks to Calman and the Royal College of Psychiatrists)