Effectiveness of a Participatory Ergonomics Intervention in Reducing Worker Pain Severity Through Physical and Psychosocial Exposure Pathways

1

• Effectiveness of a Participatory Ergonomics
  Intervention in Reducing Worker Pain Severity
  Through Physical and Psychosocial Exposure
  Pathways
• Andrew Laing

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Why Ergonomics Research?

• Effectiveness debates
• Legislation and Policies
• Evidence based decisions

• What should should an ergonomist focus on?

3
OUBPS Study Results
4
Participatory Ergonomics

• A process of ergonomic problem solving that
  incorporates input from each relevant workplace
  stakeholder group in identification of areas for
  improvement, solution development, and
  implementation of physical and work
  organizational changes in order to minimize risk
  of injury and maximize productivity.

5
Studies on EffectivenessN 11

• Inconsistent outcome variables
• Weak study designs (Control Groups N 2)
• Need for
• high quality longitudinal studies
• studies that describe and measure interventions
• studies that measure worker health outcomes

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Wells, Frazer, Norman, Laing, 2001
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1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
Intervention Outcome Pathway
UW Participative Ergonomics Process and Program
Blueprint
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
8
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
Intervention Outcome Pathway
UW Participative Ergonomics Process and Program
Blueprint
2. PLANT LEVEL WORKPLACE INTERVENTIONS
Physical Change Pathway
2b Workplace psychosocial interventions
2a Workplace physical interventions
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
9
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
Intervention Outcome Pathway
UW Participative Ergonomics Process and Program
Blueprint
2. PLANT LEVEL WORKPLACE INTERVENTIONS
Psychosocial Change Pathway
2b Workplace psychosocial interventions
2a Workplace physical interventions
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
10
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
Evaluation Framework
UW Participative Ergonomics Process and Program
Blueprint
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
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Objectives

• To evaluate
• how the specific steps within the University of
  Waterloo Ergonomics Process and Program Blueprint
  may have influenced the effectiveness of the
  physical interventions implemented.
• the effectiveness of a participatory ergonomics
  process in reducing pain severity levels through
  interventions aimed at reducing worker physical
  demands and mechanical exposures.
• the effectiveness of a participatory ergonomics
  process in reducing pain severity levels through
  interventions aimed at enhancing workplace
  communication and reducing worker psychosocial
  risk factors.

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If the proper pre-requisites exist, a
participatory ergonomics intervention will result
in

• Hypotheses
• Enhanced physical change projects
• Decreased exposure to physical risk factors
• Decreased worker perceived effort
• Enhanced communication between workplace
  stakeholder parties
• Increased worker perceived decision latitude
• Increased worker perceived influence
• Reduced pain severity reports

Measurement Tool Stakeholder Feedback
Change Specific Evaluations
Questionnaire Questionnaire
Questionnaire
Questionnaire
Questionnaire
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• METHODS

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Study Sites

• Automotive Foam Manufacturer
• Intervention (Whitby) / Control (Tilbury) Plants
• Subjects performing identical work

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Intervention Model
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Team Composition
Ergonomics Change Team
Research Team n 2
Management n 5
Labour n 4
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Evaluation ToolsStakeholder Feedback

• Input from stakeholder groups on the
  effectiveness of final changes compared to
  initial prototypes.

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Evaluation ToolsChange Specific Evaluations

• Evaluation of each change using
• EMG,
• accelerometry,
• biomechanical modeling,
• worker ratings of preference
• expert opinion of UW researchers
• Peak, Task Level, Shift Long, Overall Exposure
  Changes

Overall Time Weighted Changes Shift-Long Time
Weighted Changes Compliance of Workers
Affected At One Time / Total Workers in
Department
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Evaluation Tools Questionnaires

• Perceived Effort
• Borg CR-10 scale (Borg, 1990)
• Communication Dynamics
• 7 items, 5 point ordinal scale
• Perceived Decision Latitude
• Karaseks JCQ (1985) 9 items, 5 point ordinal
  scale
• Perceived Influence
• Greenberger (1981) 11 items, 5 point ordinal
  scale
• Reported pain severity
• body-part specific, 5 point ordinal scale

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Evaluation Tools Qualitative Process Evaluation

• Qualitative observation of elements implemented,
  and perceptions of commitment to the
  participatory process.

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Questionnaire Statistical Analyses

• Perceived effort, decision latitude, influence,
  reported pain severity
• Between Plants 2X2 ANOVAS (Pre/Post X
  Whitby/Tilbury).
• Interaction effects were of primary interest
• Communication Dynamics (only Post responses)
• Between Plants Chi Square

• Perceived effort, decision latitude, influence,
  reported pain severity
• Between Plants 2X2 ANOVAS (Pre/Post X
  Whitby/Tilbury).
• Interaction effects were of primary interest
• Communication Dynamics (only Post responses)
• Between Plants Chi Square

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Study Time Frame (Months)
11
0
Team Formation Training T0 months
Qair 1 (Pre) T1 month
Qair 2 (Post) T11
months
Change Projects / Change Specific Evaluations
T1-11 months
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RESULTS
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Results Participatory Influence on Physical
Change Projects

• 10 physical change projects implemented
• Zytec bin platforms Scoop knife handle wrap
• Rear seat back platforms Sit-stand stool
• Pack 1 8/row Velcro straightening tool
• Zytec bin build tool Air sock reposition
• Trimmer handle wrap Anti-fatigue matting
• Based on worker input and feedback, the Blueprint
  participatory process enhanced the final changes
  implemented compared to the original prototypes

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ResultsMechanical Exposures
Overall Changes Including Compliance and Job
Rotation
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ResultsMechanical Exposures
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ResultsMechanical Exposures
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ResultsMechanical Exposures

• When evaluated at the task level, the physical
  ergonomic changes implemented were successful in
  reducing physical demands.
• However, overall calculations (including
  compliance and job rotation schemes) showed only
  2 changes with substantial cumulative impacts.

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Results QuestionnairesPopulation Information
Pre-Post Matched Subjects for Questionnaires
Response Rate ()
75
64
167
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Results Perceived Effort
Intervention
Control
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Results Perceived Effort
4 body parts x 3 departments
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Results Perceived Effort
4 body parts x 3 departments
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Results Perceived Effort

• No systematic changes in perceived effort at jobs
  where interventions were implemented.

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Results Psychosocial Interventions

• 10 Psychosocial Elements introduced
• User Trials One Minute Surveys
• ECT Newsletter Suggestion Box
• Bulletin Board Logo Contest
• Shift Meetings Corporate Newspaper
• ECT Meetings Steering Committee Meetings

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Results Communication Dynamics

• Since completing the last ergonomics project
  questionnaire (June 2001)
• Overall communication between labour and
  management has been enhanced.
• Communication between you and your fellow workers
  has been enhanced.
• Communication about general ergonomic issues has
  been enhanced.
• Communication about specific ergonomic
  improvement projects has been enhanced.
• Your opinion regarding specific ergonomic
  projects has been directly asked more often.
• You have been encouraged to express your opinions
  about ergonomic issues more often.
• You have expressed your opinions regarding
  ergonomic issues more often.

• Since completing the last ergonomics project
  questionnaire (June 2001)
• Overall communication between labour and
  management has been enhanced.
• Communication between you and your fellow workers
  has been enhanced.
• Communication about general ergonomic issues has
  been enhanced.
• Communication about specific ergonomic
  improvement projects has been enhanced.
• Your opinion regarding specific ergonomic
  projects has been directly asked more often.
• You have been encouraged to express your opinions
  about ergonomic issues more often.
• You have expressed your opinions regarding
  ergonomic issues more often.

• Since completing the last ergonomics project
  questionnaire (June 2001)
• Overall communication between labour and
  management has been enhanced.
• Communication between you and your fellow workers
  has been enhanced.
• Communication about general ergonomic issues has
  been enhanced.
• Communication about specific ergonomic
  improvement projects has been enhanced.
• Your opinion regarding specific ergonomic
  projects has been directly asked more often.
• You have been encouraged to express your opinions
  about ergonomic issues more often.
• You have expressed your opinions regarding
  ergonomic issues more often.

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Results Communication Dynamics
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Results Qualitative Observations of Psychosocial
Interventions

• 10 Psychosocial Elements introduced
• User Trials One Minute Surveys
• ECT Newsletter Suggestion Box
• Bulletin Board Logo Contest
• Shift Meetings Corporate Newspaper
• ECT Meetings Steering Committee Meetings
• Lack of Commitment to Participatory Process
  Observed

• 10 Psychosocial Elements introduced
• User Trials One Minute Surveys
• ECT Newsletter Suggestion Box
• Bulletin Board Logo Contest
• Shift Meetings Corporate Newspaper
• ECT Meetings Steering Committee Meetings

38
Results Qualitative Observations of Psychosocial
Interventions

• 10 Psychosocial Elements introduced
• User Trials One Minute Surveys
• ECT Newsletter Suggestion Box
• Bulletin Board Logo Contest
• Shift Meetings Corporate Newspaper
• ECT Meetings Steering Committee Meetings
• Lack of Commitment to Participatory Process
  Observed

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Results Decision Latitude
Intervention
Control
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Results Influence
Intervention
Control
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Results Pain Severity - Components
Intervention
Control
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Results Pain Severity Plant Wide
Intervention
Control
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Discussion Physical Change Pathway
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
UW Participative Ergonomics Process and Program
Blueprint
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
of changes implemented Extent to which changes
used Quality of communications Amount of feedback
acted on
Compliance of workers affected Ergonomic
change quality of changes implemented
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
Distribution of WMSD symptoms
Psychosocial Time delay
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
44
Discussion Physical Change Pathway
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
UW Participative Ergonomics Process and Program
Blueprint
10 physical change projects
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
of changes implemented Extent to which changes
used Quality of communications Amount of feedback
acted on
Compliance of workers affected Ergonomic
change quality of changes implemented
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
Distribution of WMSD symptoms
Psychosocial Time delay
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
45
Discussion Physical Change Pathway
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
UW Participative Ergonomics Process and Program
Blueprint
10 physical change projects
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
Only 2 with substantial overall impacts
of changes implemented Extent to which changes
used Quality of communications Amount of feedback
acted on
Compliance of workers affected Ergonomic
change quality of changes implemented
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
Distribution of WMSD symptoms
Psychosocial Time delay
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
46
Discussion Physical Change Pathway
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
UW Participative Ergonomics Process and Program
Blueprint
10 physical change projects
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
Only 2 with substantial overall impacts
of changes implemented Extent to which changes
used Quality of communications Amount of feedback
acted on
Compliance of workers affected Ergonomic
change quality of changes implemented
Only 1 position with sig. decreased perceived
effort
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
Distribution of WMSD symptoms
Psychosocial Time delay
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
47
Discussion Physical Change Pathway
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
UW Participative Ergonomics Process and Program
Blueprint
10 physical change projects
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
Only 2 with substantial overall impacts
of changes implemented Extent to which changes
used Quality of communications Amount of feedback
acted on
Compliance of workers affected Ergonomic
change quality of changes implemented
Only 1 position with sig. decreased perceived
effort
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
1 sig. decrease leg pain in Components
department
Distribution of WMSD symptoms
Psychosocial Time delay
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
48
Discussion Psychosocial Change Pathway
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
UW Participative Ergonomics Process and Program
Blueprint
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
of changes implemented Extent to which changes
used Quality of communications Amount of feedback
acted on
Compliance of workers affected Ergonomic
change quality of changes implemented
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
Distribution of WMSD symptoms
Psychosocial Time delay
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
49
Discussion Psychosocial Change Pathway
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
UW Participative Ergonomics Process and Program
Blueprint
10 Psychosocial projects
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
of changes implemented Extent to which changes
used Quality of communications Amount of feedback
acted on
Compliance of workers affected Ergonomic
change quality of changes implemented
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
Distribution of WMSD symptoms
Psychosocial Time delay
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
50
Discussion Psychosocial Change Pathway
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
UW Participative Ergonomics Process and Program
Blueprint
10 Psychosocial projects
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
Ergo communication sig. increased
of changes implemented Extent to which changes
used Quality of communications Amount of feedback
acted on
Compliance of workers affected Ergonomic
change quality of changes implemented
3. PRIMARY HEALTH OUTCOMES
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
Distribution of WMSD symptoms
Psychosocial Time delay
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
51
Discussion Psychosocial Change Pathway
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
UW Participative Ergonomics Process and Program
Blueprint
10 Psychosocial projects
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
Ergo communication sig. increased
of changes implemented Extent to which changes
used Quality of communications Amount of feedback
acted on
Compliance of workers affected Ergonomic
change quality of changes implemented
3. PRIMARY HEALTH OUTCOMES
Unchanged perceived decision latitude and
influence
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
Distribution of WMSD symptoms
Psychosocial Time delay
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
52
Discussion Psychosocial Change Pathway
1 MANAGEMENT/ WORKFORCE ATTITUDES TO CHANGING
THE WORK ENVIRONMENT TO ADDRESS WMSDS
UW Participative Ergonomics Process and Program
Blueprint
10 Psychosocial projects
2. PLANT LEVEL WORKPLACE INTERVENTIONS
2b Workplace psychosocial interventions
2a Workplace physical interventions
Ergo communication sig. increased
of changes implemented Extent to which changes
used Quality of communications Amount of feedback
acted on
Compliance of workers affected Ergonomic
change quality of changes implemented
3. PRIMARY HEALTH OUTCOMES
Unchanged perceived decision latitude and
influence
3b Change in communication levels and/or
psychosocial exposures (questionnaires)
3a1 Change in mechanical exposures (change
specific evaluations)
3a2 Change in Perceived Effort (questionnaires)
Plantwide pain levels did not change
Distribution of WMSD symptoms
Psychosocial Time delay
4 CHANGES IN PAIN / DISCOMFORT (questionnaires)
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Potential Confounders

• Differential Study Site Experiences
• Line speed changes
• New plant managers
• Contract negotiations

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Conclusions

• The Blueprint participatory model enhanced the
  quality and impact of each of the final physical
  change projects.
• The Intervention Outcome Pathway model was
  helpful in interpreting the results, and in
  performing diagnostic evaluations of the
  different elements involved in the ergonomic
  intervention.

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Conclusions

• Peak and task-level cumulative exposures were
  decreased by each of the 10 change projects.
• However, when shift long job demands and job
  rotation schedules were considered, the
  cumulative impacts were sufficient to reduce
  overall mechanical exposures for only two
  changes.
• Perceived Effort did not systematically change
• This might, in part, explain the decreased pain
  severity values in only one department.

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Conclusions

• The participatory ergonomics intervention
  resulted in enhanced communication dynamics
  regarding ergonomic issues.
• Lack of commitment lead to lack of significant
  change in perceived Decision Latitude and
  Influence.
• This, in part, explains the lack of changes in
  plant-wide Pain Severity levels.

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Recommendations

• Additional research should be performed to
  determine
• the mechanical exposure changes necessary to
  reduce pain severity levels,
• the intensity of psychosocial interventions
  necessary to alter perceived decision latitude
  and influence levels, and
• the magnitude of psychosocial risk factor changes
  necessary to influence pain severity levels,
• The success of the participatory process in other
  worksites.

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Recommendations

• The Ergonomics Change Team evaluated in this
  study should
• be encouraged to commit to the participatory
  change process, and
• continue to implement physical and psychosocial
  ergonomic changes in hopes that additional
  interventions will involve enough cumulative
  benefits to influence primary indicators of
  health.

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Recommendations

• To enhance chances of improved indicators of
  health, a corporate ergonomist should be involved
  to direct the teams efforts.

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• THANK YOU

You can buy peoples time, you can buy their
physical presence at a given place, you can even
buy a measured number of their skilled muscular
motions per hour. But you cannot buy loyalty,
you cannot buy the devotion of hearts, minds, or
souls. You must earn them. - in Saari, 1989