TWG-IS Ergonomic Intervention Pilot Study

Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo

Wells, R.P .

1

, Norman, R.W.

1,

Frazer, M.B.

1

, Neumann, W.P.

1

, Cole, D.

2

, Shannon, H.

2

, Kerr, M.S.

2 1 University of Waterloo, Kinesiology Department, Waterloo, ON 2 Institute for Work and Health, Toronto, ON

ACKNOWLEDGEMENTS

: The authors acknowledge the funding and active support of the Institute for Work and Health (Toronto, Canada), the Workers Safety and Insurance Board, the Ergonomics Initiative funding companies: General Motors of Canada, A.G. Simnpson Inc. and The Woodbridge Group, and HEALNet (Health Evidence and Linkage Network), a member of the Networks of Centres of Excellence program which is a unique partnership among Canadian Universities, Industry Canada and the federal research granting councils.

Objectives

•

Assess the effectiveness of ergonomic changes made at the workplace and evaluate the process of ergonomic change.

•

Assess whether changes lead to:

•

reduced physical loading on the body

•

reduced pain and fatigue or improved morale

• •

reduced injury rates and improved productivity cost justifiable benefits

Background

Interactions among the ergonomic design of work, worker perceptions of work-related social factors, worker and management personal factors, and the organization of work are known to influence the incidence and severity of occupational injury, quality and productivity.

(Norman et. al., 1998)

Exactly how these factors interact and the extent of improvement in outcomes that can be produced by improved ergonomic design of jobs are unknown. Understanding the interactions between physical and psychosocial factors and how to change them is important if ineffectual changes and/or ineffectual methods of introducing change are to be avoided by workplace parties. We need convincing evidence of the effectiveness of various kinds of interactions for the prevention of musculoskeletal disorders.

REFERENCES: 1.

Norman, R., Wells, R., Neumann, P., Frank, J., Shannon, H., Kerr, M., and the Ontario Universities Back Pain Study (OUBPS) Group (1998).

A comparison of peak vs cumulative physical work exposure risk factors for the reporting of low back pain in the automotive industry

. Clinical Biomechanics 13; pp 561-573.

Phase 1 Measures

The initial site for this study is the Woodbridge Foam Company Tilbury Location. Here, there are two Ennerflex Foam Lines in operation. Line 2 is the target group for intervention, and Line 1 will act as a ‘control group’ without intervention.

All operators on line 1 and line 2 were given a questionnaire package which aided in researchers’ understanding of the type of demands associated with the work done, possible trends in injury/discomfort across the working population and general perceptions about the workplace tasks and environment. Six participants from each line were then randomly chosen from all operators who had completed questionnaires to participate in physical loading measures across 8 workstations.

• • • •

Physical Loading Measures included: WATBAK analysis used to calculate acute and cumulative loads on the low back and shoulders EMG data of forearm extensors and trapezius muscles average and peak pinch/grip forces (collected through force matching) record of hand actions observed

Study Plan: Phase 1: Observation A (pre) Phase 2: Intervention Phase 3: Observation B (post) Phase 4: Follow-up

Detailed assessments of both Line 1 and Line 2 Change team works on Line 2 only Detailed assessments of both Line 1 and Line 2 Outcome variables tracked for both Line 1 and Line 2

Key Variables of Interest

Worker Health Variables - Pain, Injury Fatigue Worker Exposure Variables - Known physical and psychosocial

risk factors

Plant Performance Variables - Quality, Productivity, Efficiency

Plant/Company Benefits

• • • • • •

Plant personnel gain access to state-of-the science ergonomics methods and knowledge Plant receives summary information of exposures Plant gains expert input into improvements Study acts as “change agent”: Change

happens!

Effectiveness of change (injury risk, productivity, quality, pain) will be rigorously evaluated) Methods used in this study could be adapted for a general ergonomics program Cumulative Compression

Phase 1 Results

Physical Loading Data

40 35 30 25 20 15 10 5 0 P ul le r C le an L id s C le an B ow ls W ax er S ta m p n/a S cr ap Tr im Line 1 Line 2

Both peak and accumulated L4/L5 loads were higher for Line 2 participants than Line 1 (Figure 1). ‘Puller’ had higher moment and

Figure 1 : Cumulative Compression across Jobs for each Line

compression values than other jobs Overall Rating of Exertion across both lines. Dominant shoulder flexor moments showed a similar trend.

10 9 8 7 6 5 4 3 2 1 0 Pu lle r Cl ea n Li ds Cl ea n Bo w ls W ax er St am pe r Sc ra p Tr im In sp ec t

Perceived Load Data

Figure 2 :

Perceived physical load data was

Overall Rating of Exertion across Jobs

collected using the questionnaire. Line 2 rated overall rating of perceived effort scores higher than

Pa ck Line 1 Line 2

Line 1 (Figure 2). On-line jobs (puller, cleaners, waxer) were generally rated higher than off-line jobs (stamp, scrap, trim, inspect, pack).

What’s Next

The Ergonomics Change Team is currently in Phase 2 of this project, developing improvement ideas to reduce the physical load placed on operators at each workstation on Line 2. This continuous phase of change is set to continue for three months.

Once changes are in place, post-measures (questionnaires and physical measures) of both lines will be completed.