Transcript Back Injury Prevention Program

Effectiveness of a Participatory Ergonomics
Intervention in Reducing Worker Pain
Severity Through Physical and
Psychosocial Exposure Pathways
Andrew Laing
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Why Ergonomics Research?


Effectiveness debates

Legislation and Policies

Evidence based decisions
What should should an ergonomist
focus on?
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
OUBPS Study Results
Biomechanical Risk Factors:
(Measured):
“higher” peak shear
“higher” peak hand force
“higher” cumulative compression
“higher” forward bending
“higher” perceived phys demands
Individual Risk Factors:
Prior WCB Low Back Claim
Higher body mass index (Ht. Wt.)
31.4%
4.7%
11.5%
Psychosocial Risk Factors:
(Perceived / questionnaire)
“poorer” workplace social environment
“higher” perceived education
(compared to peers)
“lower” job control
“higher” co-worker support
“higher” job satisfaction
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
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.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Studies on Effectiveness
N = 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
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Wells, Frazer,
Norman, Laing, 2001
Intervention
Outcome
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:
2a: Workplace
physical
interventions
3a2: Change in
Perceived Effort
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
2b: Workplace
psychosocial
interventions
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3. PRIMARY
HEALTH
OUTCOMES
Intervention
Outcome
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:
2a: Workplace
physical
interventions
3a2: Change in
Perceived Effort
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
Physical
Change
Pathway
2b: Workplace
psychosocial
interventions
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3. PRIMARY
HEALTH
OUTCOMES
Intervention
Outcome
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:
2a: Workplace
physical
interventions
3a2: Change in
Perceived Effort
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
Psychosocial
Change
Pathway
2b: Workplace
psychosocial
interventions
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3. PRIMARY
HEALTH
OUTCOMES
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:
2a: Workplace
physical
interventions
3a2: Change in
Perceived Effort
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
2b: Workplace
psychosocial
interventions
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3. PRIMARY
HEALTH
OUTCOMES
Objectives
To evaluate:
1. how the specific steps within the University of Waterloo
Ergonomics Process and Program Blueprint may have
influenced the effectiveness of the physical interventions
implemented.
2. the effectiveness of a participatory ergonomics process in
reducing pain severity levels through interventions aimed at
reducing worker physical demands and mechanical
exposures.
3. 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.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
If the proper pre-requisites exist, a
participatory ergonomics intervention will
result in:
Hypotheses:
1.
2.
3.
4.
5.
6.
7.
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
Department of Kinesiology - Biomechanics
Measurement Tool:
Stakeholder Feedback
Change Specific
Evaluations
Questionnaire
Questionnaire
Questionnaire
Questionnaire
Questionnaire
University of Waterloo, 2002
METHODS
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Study Sites
 Automotive Foam Manufacturer
 Intervention (Whitby) / Control (Tilbury)
Plants
 Subjects performing identical work
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Intervention Model
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Team Composition
Ergonomics
Change Team
Management
n=5
Labour
n=4
Department of Kinesiology - Biomechanics
Research Team
n=2
University of Waterloo, 2002
Evaluation Tools:
Stakeholder Feedback

Input from stakeholder groups on
the effectiveness of final changes
compared to initial prototypes.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Evaluation Tools:
Change 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
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Evaluation Tools:
Questionnaires
 Perceived Effort:
 Borg CR-10 scale (Borg, 1990)
 Communication Dynamics:
 7 items, 5 point ordinal scale
 Perceived Decision Latitude:
 Karasek’s 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
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Evaluation Tools:
Qualitative Process Evaluation
 Qualitative observation of elements
implemented, and perceptions of
commitment to the participatory
process.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
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
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Study Time Frame (Months)
11
0
Team
Formation &
Training
T=0 months
Q’air #1 (Pre)
T=1 month
Q’air #2 (Post)
Change Projects / Change
Specific Evaluations
T=11 months
T=1-11 months
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
RESULTS
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results:
Participatory Influence on
Physical Change Projects
 10 physical change projects implemented:
Zytec bin platforms
Rear seat back platforms
Pack 1 – 8/row
Zytec bin build tool
Trimmer handle wrap
Scoop knife handle wrap
Sit-stand stool
Velcro straightening tool
Air sock reposition
Anti-fatigue matting
 Based on worker input and feedback, the
Blueprint participatory process enhanced the
final changes implemented compared to the
original prototypes
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results:
Mechanical Exposures
63
Change
Project
Estimated ‘Peak’
Exposure Changes
Pack 1 –
8/row
Peak Dominant trap
activity decreased by
19.8% (from 242 to 194
mV).
Zytec Bin
Platforms
Joint shear decreased
from 746 to 196N. No
change as in LBPRIs as
removing bottom parts
with platform has
almost the same posture
as removing middle
parts without the
platform, and are peak
loading postures.
LBPRIs: Moment - 0.36
to 0.28, Compression 0.35 to 0.28, Rshear 0.37 to 0.22
Platform
for Rear
Seat
Backs
Estimated 4D
Watbak
Cumulative
Exposure
Changes / Task
Level Time
Weighted Cum
Values
Average
dominant trap
activity
decreased by
32% from 50 to
34 mV.
LBPRIs - Cum
Moment: 0.5 to
0.45, Cum
Comp: .043 to
0.41, Cum
Rshear: 0.53 to
0.47
Combined
LBPRI
Changes
Full Shift
Time
Weighted
Changes
Affects How
Positions at
Once /
Positions in
Dept
Estimated
Complian
ce
Time
Overall
Weighted
Changes
Changes
Including
Considering
Compliance
Compliance
and Job
and Job
Rotation
Rotation
N/A
Average
dominant
trap EMG
value
decreased
by 23.8%.
N/A
1 / 11
100%
1 / 10
100%
APDF0.5
dominant
trapezius
EMG value
decreased by
2.2%.
Combined
LBPRI
unchanged at
0.25.
LBPRIs – Cum
Mom.: 0.58 to
0.39, Cum
Comp.: 0.48 to
0.38, Cum
Rshear: 0.61 to
0.39
Decrease
from 0.43
to 0.19.
N/A
1 / 10
100%
Decrease
from 0.39
to 0.34.
Combined
LBPRI
dropped
from 0.23 to
0.16.
Results:
Mechanical Exposures
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results:
Mechanical Exposures
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results:
Mechanical 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.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Questionnaires
Population Information
Pre-Post Matched Subjects for Questionnaires
Same Dept
Pre-Post
Matches
44
Total
Population
Response
Rate (%)
75
58.7
Tilbury
Foam
39
64
60.9
Total
83
167
59.7
Whitby
Foam
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Perceived Effort
Intervention
Control
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Perceived Effort
4 body parts x 3 departments
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Perceived Effort
4 body parts x 3 departments
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Perceived Effort

No systematic changes in perceived
effort at jobs where interventions
were implemented.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Psychosocial
Interventions

10 Psychosocial Elements introduced:
User Trials
ECT Newsletter
Bulletin Board
Shift Meetings
ECT Meetings
One Minute Surveys
Suggestion Box
Logo Contest
Corporate Newspaper
Steering Committee Meetings
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Communication Dynamics
Since completing the last ergonomics project questionnaire (June 2001):
1.
Overall communication between labour and management has been enhanced.
2.
Communication between you and your fellow workers has been enhanced.
3.
Communication about general ergonomic issues has been enhanced.
4.
Communication about specific ergonomic improvement projects has been
enhanced.
5.
Your opinion regarding specific ergonomic projects has been directly asked
more often.
6.
You have been encouraged to express your opinions about ergonomic issues
more often.
7.
You have expressed your opinions regarding ergonomic issues more often.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Communication Dynamics
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Qualitative Observations
of Psychosocial Interventions

10 Psychosocial Elements introduced:
User Trials
ECT Newsletter
Bulletin Board
Shift Meetings
ECT Meetings

One Minute Surveys
Suggestion Box
Logo Contest
Corporate Newspaper
Steering Committee Meetings
Lack of Commitment to Participatory
Process Observed
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Qualitative Observations
of Psychosocial Interventions

10 Psychosocial Elements introduced:
User Trials
ECT Newsletter
Bulletin Board
Shift Meetings
ECT Meetings

One Minute Surveys
Suggestion Box
Logo Contest
Corporate Newspaper
Steering Committee Meetings
Lack of Commitment to Participatory
Process Observed
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Decision Latitude
Intervention
Control
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Influence
Intervention
Control
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Pain Severity - Components
Intervention
Control
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Results: Pain Severity – Plant Wide
Intervention
Control
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
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
3a2: Change in
Perceived Effort
(questionnaires)
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
3. PRIMARY
HEALTH
OUTCOMES
Distribution of WMSD symptoms
Psychosocial
Time delay
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
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
3a2: Change in
Perceived Effort
(questionnaires)
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
3. PRIMARY
HEALTH
OUTCOMES
Distribution of WMSD symptoms
Psychosocial
Time delay
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
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
Only 2 with substantial
overall impacts
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
3a2: Change in
Perceived Effort
(questionnaires)
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
3. PRIMARY
HEALTH
OUTCOMES
Distribution of WMSD symptoms
Psychosocial
Time delay
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
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
Only 2 with substantial
overall impacts
Only 1 position with sig.
decreased perceived effort
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
3a2: Change in
Perceived Effort
(questionnaires)
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
3. PRIMARY
HEALTH
OUTCOMES
Distribution of WMSD symptoms
Psychosocial
Time delay
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
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
Only 2 with substantial
overall impacts
Only 1 position with sig.
decreased perceived effort
2. PLANT LEVEL WORKPLACE
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
3a2: Change in
Perceived Effort
(questionnaires)
1 sig. decrease – leg pain in
Components department
2b: Workplace
psychosocial
interventions
2a: Workplace
physical
interventions
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
3. PRIMARY
HEALTH
OUTCOMES
Distribution of WMSD symptoms
Psychosocial
Time delay
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
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:
2a: Workplace
physical
interventions
Compliance
# of workers affected
Ergonomic change quality
# of changes implemented
3a2: Change in
Perceived Effort
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
2b: Workplace
psychosocial
interventions
# of changes implemented
Extent to which changes used
Quality of communications
Amount of feedback acted on
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3. PRIMARY
HEALTH
OUTCOMES
Distribution of WMSD symptoms
Psychosocial
Time delay
Department of
4: CHANGES IN PAIN
/ DISCOMFORT
Kinesiology
(questionnaires)- Biomechanics
University of Waterloo, 2002
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
3a2: Change in
Perceived Effort
(questionnaires)
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
3. PRIMARY
HEALTH
OUTCOMES
Distribution of WMSD symptoms
Psychosocial
Time delay
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
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
3a2: Change in
Perceived Effort
(questionnaires)
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
3. PRIMARY
HEALTH
OUTCOMES
Distribution of WMSD symptoms
Psychosocial
Time delay
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
Ergo communication
sig. increased
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
3a2: Change in
Perceived Effort
(questionnaires)
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
3. PRIMARY
HEALTH
OUTCOMES
Distribution of WMSD symptoms
Psychosocial
Time delay
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
Ergo communication
sig. increased
Unchanged perceived
decision latitude and
influence
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
3a2: Change in
Perceived Effort
(questionnaires)
3b: Change in
communication
levels and/or
psychosocial
exposures
(questionnaires)
3a1: Change in
mechanical
exposures
(change
specific
evaluations)
3. PRIMARY
HEALTH
OUTCOMES
Distribution of WMSD symptoms
Psychosocial
Time delay
4: CHANGES IN PAIN
/ DISCOMFORT
(questionnaires)
Ergo communication
sig. increased
Unchanged perceived
decision latitude and
influence
Plantwide pain levels
did not change
Potential Confounders:
Differential Study Site Experiences
 Line
speed changes
 New
plant managers
 Contract
negotiations
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
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.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
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.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
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.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
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.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
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.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
Recommendations:

To enhance chances of improved
indicators of health, a corporate
ergonomist should be involved to direct
the team’s efforts.
Department of Kinesiology - Biomechanics
University of Waterloo, 2002
THANK YOU
“You can buy people’s 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
Department of Kinesiology - Biomechanics
University of Waterloo, 2002