Coronel Institute

Ergonomics in the construction sector

Henk van der Molen, Judith Sluiter, Monique Frings-Dresen

email: h.f.vandermolen@amc.nl j.sluiter@amc.uva.nlm.frings@amc.uva.nl

Coronel Institute of Occupational Health, Academic Medical Center, Amsterdam, The Netherlands

Arbouw, Health & Safety Institute in the Construction Industry, Amsterdam, The Netherlands

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Coronel Institute of Occupational Health

• Department of the Academic Medical Center (AMC)• Samuel Coronel (Sr) (1827-1892):

– one of the first to relate living conditions on health

• Coronel Institute:– Largest university-based center on occupational

health in the Netherlands (± 80 colleagues) – Netherlands Center for Occupational Diseases – Research Center for Insurance Medicine– Out-patient Clinic People and Work

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Arbouw

• Knowledge & Service institute for Dutch industry sector • Working circumstances & disability for work • Board of employers & employee organisations• Collectively financed

• Organisation:• Research & Development• Contract with Occupational Health & Safety services• Facilitative towards sector, e.g. instruments

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What works!? (examples of studies)

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What works!? (1)_ Cochrane review

• Effectiveness of interventions to prevent occupational injuries among workers at construction sites

• Systematic literature review • 7522 references• N = 5 studies with time series• Meta analysis

(van der Molen et al 2007, Lehtola et al. accepted 2008 )

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• No evidence that legislation alone is effective for reducing injuries

• Additional strategies necessary to increase compliance employers and workers to measures prescribed by legislation

• Multifaceted and continuing interventions seem effective for reducing injuries (like safety campaign and drug-free workplace program)

• Influencing safety culture and enforcement / feedback important elements of these interventions

Implications on basis of systematic review

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What works!? (2) _ technical devices

• Effect of adjusting working height materials & mechanisation of transport on work demands

• Controlled field study; real time observations• N = 10 bricklayers, 10 assistants

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Results with respect to day exposures:

bricklayers:• frequency trunk flexion > 60º : 79% (920 times)• duration trunk flexion > 60º : 52% (42

minutes)

assistants:• frequency trunk flexion > 60º : 94% (474 times)• duration trunk flexion > 60º : 92% (25

minutes)• mmh objects > 4 kg : 86% (1326

times)

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What works!? (3)_lower weight

Effect block weight on: Compression force on low back?

Conditions 6, 11, 14 (2 types) en 16 kg N=9 blocklayers Most demanding activities

(based on field study)

Measurements Direct measurement Biomechanical modelling

(Faber et al. 2007 & Kuijer et al. 2007)

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Maximale piek compressiekracht op lage rug

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

2 handen 1hand 2 handen 1 hand 2 handen 1 hand 2 handen 1 hand 2 handen 1 hand 2 handen

oppakken vanaf 10 cmhoogte

oppakken vanaf 90 cmhoogte

oppakken vanaf steiger neerzetten in muurgrondhoogte

neerzetten in muurheuphoogte

neerzetten in muurschouderhoogte

Kra

cht

(N)

blok 6 kgblok 11 kgblok 14 kg zonder gatenblok 14 kg met gatenblok 16 kg

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What works!? (4) _ paver’s trolley

• Effect of paver’s trolley on productivity, task demands, discomfort

• Controlled field study; observations and questionnaires• N = 10 paviours

(Kunst et al. 2007)

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RESULTS

With paver's trolley Working on knees (rolling) : 141 min.Without paver's trolleyWorking on knees (crowling) : 146 min.

• No differences in:– productivity– energetic workload– local discomfort

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What works!? (5) _ergonomic measures

• Effect of use of ergonomic measures on musculoskeletal complaints

• Cohort study: 4.5 years• Questionnaires: 2 times (pre-post) • N= 1,114 carpenters, bricklayers and pavers

(van der Molen, Sluiter & Frings-Dresen 2007;

in press

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6 ergonomic measures

Mechanical transport

Liftingaids

Bricks on elevation

Mechanical transport

Mechanical paving

Mechanical kerbs placing

carpenters bricklayers pavers

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Results: primary prevention

Over a 4.5 years period:

• 17.3% incidence of low back complaints

• Frequent use of ergonomic measures is associated with a non-significant 15% reduction of the risk on reported regularly or sustained low back complaints

• ´Number needed to treat´: 38 construction workers who are regularly using ergonomic measures to prevent 1 construction worker with low back complaints

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Low back complaints

N RR (95% CI)

Materials on elevation (31 cm) 143 0,63

(0,44-0,92)

More use of elevated tubs is related to reduced low back complaints over time

Results: secondary prevention

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What works!? (5a)_Actor analysis

• Assocation between behavioural change and use of ergonomic measures

• Cross sectional study• Structered interviews • N=42;

– Employers as behavior environmental agents– Workers as behavior individual agents

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Tresle know understand want decide able

E W E W E W E W E W

A

B

C

D

E

F

G

H

IE = employers; W = workers; A-I: companies

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example Odds Ratio’s (95% CI)

Employers Bricklayers

Elevation of materials

2,4 (1,1 - 5,1) 7,2 (1,5 - 35,1)

Results

Overall:- Strength of associations between use of ergonomic measures and

behavioral change phases differs between ergonomic measures actor groups of employers and workers

- Significant positive associations between use of ergonomic measures and behavioral change phases

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- Wrist

- Underarm

- Elbow

- Shoulder

Design and development of new tools

Awkard postures and high forces when working with traditional trowel of:

What works!? (6)_Product development

(Kuyt-Evers 2006)

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Position of handle determines load on body regions

TRADITIONAL SMART ERGO

Results

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Developing effective solutions is often a long

and winding road….,

• Evaluate ergonomic measures before implementation on:• Workload / Energy• Complaints / Injuries

• Feasibility of measures for stakeholders• Employer• Worker• but also at architects, manufacturers, et cetera

Take home messages

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Exchange of knowledge (research)

• Fifth IEA symposium in Beijing 2009 • Increase of peered reviewed articles• Special issues about construction ergonomics

– Scandinavian Journal of Work, Environment & Health 2005– Applied Ergonomics 2005– American Journal of Industrial Medicine (in preparation)

• Scientific committees– IEA – ICOH

• International projects (e.g. Cochrane review safety interventions)