This presentation explores the diverse health of the South African working population, and how health affects workers’ performance. Health that is influenced by both factors outside of the work environment and factors intrinsic to the work setting will be discussed. The paper further highlights the important of workplace wellness programmes and how these can be used within an ergonomics framework to promote health and wellbeing in the workplace.

1. Speaker : Professor Candice Christie
Presentation Title : Putting the worker at the centre of the ‘human-
machine’ interface

2. Introduction
Our health affects our work

3. Introduction
And our work affects our health in many ways

4. Introduction
The uniqueness of the work
environment in South Africa

5. Introduction
Industrially Developing Countries have a vast array of:
• Cultures
• Availability of resources
• Levels of infrastructure
• Work environments/conditions
O’Neill (2000)

6. Introduction
South African context:
• South Africa is a middle income country
• Extremes of wealth and poverty
• Technologically advanced
• Preponderance of manual work
• Very diverse work situations

7. Introduction
• Differing levels of education
• Differing socio-economic strata
• Living conditions
• Nutritional habits
• Physical work at home/after hours
• Disease patterns

8. Introduction
How work affects our health

9. How work affects our health

10. Physical affects of work: Fatigue
LEVEL Oxygen
consumption
(mlO2.kg-1.min-1)
Energy
Expenditure
(kcal.min-1)
Heart Rate
(bt.min-1)
Light 6.1-15.2 2.0-4.9 >90
Moderate 15.3-22.9 5.0-7.4 90-110
Heavy 23.0-30.6 7.5-9.9 110-130
Very Heavy 30.7-38.3 10.0-12.4 130-150
Unduly Heavy 38.4- 12.5- <150
Saunders and McCormick, 1992

11. Physical affects of work: SA example
Christie, 2008
Variable 1st
Quarter
2nd
Quarter
3rd
Quarter
4th
Quarter
WHR
(bt.min-1)
121
(11.1)
119
(12.5)
126
(12.5)
127
(13.3)
VO2
(ml.kg-1.min-1)
19.9
(6.5)
18.8
(6.3)
21.8
(6.8)
22.9
(7.2)
EE
(kJ.min-1)
26.4
(8.6)
24.9
(8.2)
28.8
(8.6)
30.3
(9.4)

12. Physical aspects of work
16
18
20
22
24
26
28
30
32
OxygenConsumption(ml.kg-1.min-1)
Task A Task B
*

13. Physical aspects of work
Body mass loss: 1.94 kg
Christie, 2008

14. Physical aspects of work
Energy Deficit: 8661.8 kJ
Christie, 2008

15. Physical aspects of work
Christie et al., 2008
TASK Heart Rate
(bt.min-1)
Oxygen Uptake
(ml.kg-1.min-1)
Oxygen Uptake
(L.min-1)
Cutting
122
(14)
21.42
(8.97)
1.29
(0.54)
Topping 117
(14)
19.63
(8.38)
1.19
(0.50)
Stacking 125
(17)
22.96
(8.67)
1.38
(0.51)
Overall
121
(15)
21.34
(8.41)
1.29
(0.50)

16. Physical aspects of work
Log Mass Action
Compressive
Force
(N)
Shearing
Force
(N)
10 kg 1 hand 1213 286
2 hand 2924 333
60 kg 1 hand 3593 854
2 hand 10794 996
120 kg 1 hand 5398 1308
2 hand 18370 1526
Christie et al., 2008

17. Physical aspects of work
Todd, 2007
0
10
20
30
40
50
60
70
0 2 3 5 7 8 10
Time (s)
Position(Degrees)andVelocity(m.s-1
)
Lateral velocity
Sagittal Position
Twisting velocity

18. Psychological aspects of work
Work schedules

19. Psychological aspects of work
Commuting to work

20. Psychological aspects of work
Balancing work and family

21. Psychological aspects of work
Control at work, demands and decision latitude
• High psychological demands
• High levels of decision making authority
• High levels of skill utilization
• ‘Decision latitude’
= self esteem and self efficacy

22. Psychological aspects of work
Control at work, demands and decision latitude
• Jobs that make high demands
• Offer little ‘decision latitude’
= Job Strain
= More likely to suffer psychological distress
= Higher risk of CDL
= Higher risk for unhealthy coping behaviours

23. Psychological aspects of work
Balance between efforts and rewards
High Efforts
Low Rewards
= poor health

24. Health
Our health affects our work

25. Quadruple burden of disease
The Lancet 2009 374, 934-947DOI: (10.1016/S0140-6736(09)61087-4)

26. Impact of health on work performance
High work
demands
Poor health
= less productive

27. Incidence of Poverty

28. World Health Organization
World Health Organization:
“Wealth of the poor people is in their
individual capabilities and their ‘assets’,
the most important being their health
which is their most precious
commodity”

29. World Health Organization
• Good health enables poor people to participate in
the job market
• It is the key to productivity particularly in a
people dominated working environment
• Physically healthy, strong body is an asset
• While a sick and weak body is a liability both to
employee and employer

30. Coupled with nutritional status
PROTEIN
(g)
FAT
(g)
CHO
(g)
TOTAL
ENERGY
(kJ)
RDA 65.0 30.0-80.0 100.0 8000.0
Group 1 40.5 26.7 110.9 3949.1
Group 2 56.2 23.1 186.8 5346.0
Christie, 2008

31. Basic Human Needs
Self-Actualisation
Esteem
Love
Safety
Biological and Physiological
Needs
Adapted from Abraham Maslow (1943)

32. South Africa’s unique environment
HIV/AIDS;
Infectious
diseases
5.3 mill South Africans with HIV/AIDS
(UNAID, 2003)

33. Non-communicable Diseases
Bradshaw et al, NCDs: a race against time

34. Non-communicable Diseases
Bradshaw et al, NCDs: a race against time

35. Non-communicable Diseases
Bradshaw et al, NCDs: a race against time

36. DALYs in IDCs in 2004
(Econex, NHI Note 2, 2009)

37. DALYs for developed countries 2004
(Econex, NHI Note 2, 2009)

38. Absolute burden of disease
(Econex, NHI Note 2, 2009)

39. (Econex, NHI Note 2, 2009)

40. Solutions
1. Worksite Wellness Programmes
2. ‘Fitting the Job for Total Worker Health’

41. Solutions
Worksite
Wellness
Programmes:
‘Change
behaviours’
Work itself:
‘Causes
behaviours’

42. Work impacts:
1. Eating and exercise patterns
2. Lack of decision-making are strongly associated with:
• obesity,
• alcohol consumption,
• smoking and,
• lack of exercise

43. Ergonomics Solution – an example
Improved work organization:
Time,
space,
material and,
social support for:
Improvements in:
Dietary choices, smoking cessation, participation in
exercise, and improved work-family balance

44. Where does Ergonomics fit in?
• Occupational ergonomics is the science of
‘fitting the task to the worker’
• It is not only concerned with work station
design or preventing MSDs
• It provides a framework to address the
workplace preconditions of the job stress

45. Ergonomics and WWP
Ergonomists:
Address the broad range of work organization issues such as job
design to:
• Increase decision latitude
• Optimize work schedules
• Improve quality of supervision
Engaging an ergonomist can remove obstacles to programme
participation and increase trust in employers

46. Participatory Approach
Participatory ergonomics offers a useful model for
programme design starting with engaging workers
themselves in identifying their health priorities and
environmental factors that affect their health

47. Ways to incorporate Ergonomics
1. Partner with your organizational team
2. In programme goals and activities accommodate
for the physical and social demands of workers
3. Use a participatory approach

48. Thank you!
Prof. Candice Christie
Department of Human Kinetics and Ergonomics
Rhodes University
Grahamstown
c.christie@ru.ac.za
@CandiceHKE