03 Prevention in Practice Print Out

Workshop Ergonomic Work Design and Prevention

of Work-Related Musculoskeletal Disorders (MSDs)

Prevention of MSDs in Practice

Dr. Rolf Ellegast

XIX. World Congress on Saftety

and Health at Work September 11-15, 2011, Istanbul

Ellegast_2011

Prevention of Work-Related MSDs

Reduction of work load/exposure by

ergonomic

design

of work

equipment

and work

places,

e.g. by

using

lifting

aids

health-oriented

organisation

of working

processes

Improvement of individual pre-conditions, e.g. by

individual

training

to build

muscle, behavioural

training,

e.g. back exercises

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Grinding in a shipyard

Examples Ergonomic Design of Equipment/Tools

Ellegast_2011

Classes

of risk

-

4 OWAS*

risk

categories(as percentage

of working

time):

Class

1: No intervention

requiredClass

2: Corrective

action

should

be

taken

during

next

regular

review

Class

3: Corrective

action

should

be

taken

as soon

as possibleClass

4: Corrective

action

should

be

taken

immediately

*

OVAKO-Working-Posture-Analysing-System

9,1%

84,8%

1,4% 4,7%


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Ergonomic Redesign of the grinding tool


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before: after:9,1%

84,8%

1,4% 4,7%

93,8%

6,2% 0%


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Grinding

in a shipyard: Quantification

of work

load

reduction

7,9

84,8

2,3

5,1

4,2

2,1

90,3

3,5

98,1

1,9

36,7

6,1

0,9

56,4

0 20 40 60 80 100

gerade

gebeugt

tordiert

gebeugt und tordiert

Stehen

Hocken

Knien

Gehen

Anteil an Arbeitszeit (%)

erg. Schleiferkonv. Schleifer

Bent

forward

& twisted

twisted

bent

forward

neutral

Low

erex

t rem

etie

s walking

kneeling

squatting

standing

Trun

k

Percentage

of working

time

afterbefore


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Use of supporting tools

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Source: Rehme, Bau BG

Brick

laying

machine


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Example:

Removal men

(BG Verkehr)

Use

of a shoulder

strap

for

big

material


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Example:

Cleaning

of sewage

ductsbefore: after:Manual lifting

of the

duct

cover

Use

of a lifting

aid

(magnetic

pick-up

tool)


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Example:

Wheel changing

(busses)

before: after:manual

assembling

Use

of a hydraulic

jack


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Use of handling aids

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Luggage service at the airport

Use

of lifting

aids

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Impact on the

work

organisation

handled

luggage

Abgefertigtes Gepck

0

50

100

150

200

250

300

350

400

450

500

P01 P02 P03 P04 P05 P06 P09 P10 Versuchsperson

A

n

z

a

h

l

G

e

p

c

k

s

t

c

k

e

\

h

abgefertigt ohne Vaculex

abgefertigt mit Vaculex

davon manuell gehoben

292

230 => -22%

Results luggage service

handled luggage

N

u

m

b

e

r

o

f

h

a

n

d

l

e

d

l

u

g

g

a

g

e

p

e

r

h

o

u

r

Subjects

With lifting aid

Without lifting aid

With lifting aid, manually handled

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Bellyloader

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Results Bellyloader

Average

duration

of luggage

handling

(bellyloader)Unloading: -45%Loading: -53%

Mittlere Handhabungsdauer pro Gepckstck in Sekunden

1,27

1,52

0,70 0,72

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40

1,60

1,80

2,00

Entladung Beladung

H

a

n

d

h

a

b

u

n

g

s

d

a

u

e

r

[

s

]

ohne PowerStow

mit PowerStow

n = 373 n = 383n = 336 n = 475

Average duration of luggage handling [s]d

u

r

a

t

i

o

n

o

f

l

u

g

g

a

g

e

h

a

n

d

l

i

n

g

[

s

]

Unloading Loading

without

PowerStow

with

PowerStow

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Proportion of knee-straining

postures (bellyloader)

0,0

10,0

20,0

30,0

40,0

50,0

60,0

70,0

80,0

90,0

100,0

Kriechen Hocken Knien Fersensitz Knien mitAbsttzung

Knien ohneAbsttzung

Summe:Kniebelastende

Haltungen

Haltung

Z

e

i

t

a

n

t

e

i

l

[

%

]

Beladung mit PowerStow

Beladung ohne PowerStow

Entladung mit PowerStow

Entladung ohne PowerStow

Results Bellyloaderp

e

r

c

e

n

t

a

g

e

o

f

t

i

m

e

Postures

crawling squatting sitting

on

heels

kneeling

(unsupported)

kneeling

(supported)

total

loading

(with

PowerStow)

loading

(without

PowerStow)

unloading

(with

PowerStow)

unloading

(without

PowerStow)

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Experimental Technologies in Luggage Handling

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WorkplaceWorkplace DesignDesign

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Warehouse Working

before:

unfavourable

working

heights

leading

to awkward

postures when

taking

and scanning

goods

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after:

Modification

of working

heights

leading

to better

(upright) postures when

taking

and scanning

goods

Warehouse Working

Ellegast_2011

p

e

r

c

e

n

t

a

g

e

o

f

t

i

m

e

before

after

Trunk inclination

Warehouse Working

angular categories []

Ellegast_2011

Examples of Prevention Ergonomic Workplace Design

Sewing Workplace

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Ergonomic Archetyp of a Sewing Workplace

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Features

Quick change

between

sitting and standing

Individually

adjustable

arm rests

Variety

of adjustment possibilities

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Extension of leg and foot

space

Chooseable

position

of pedals

Features

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Comparison: Before and After

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Trunk bending

Number

of measurement

before

(sitting)

after

(sitting)after

(standing)

A

n

g

l

e

o

f

t

r

u

n

k

b

e

n

d

i

n

g

[

]


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Rotation of forearm

(pronation/supination)

left

arm

right arm

Number

of measurement

A

n

g

l

e

o

f

f

o

r

e

a

r

m

r

o

t

a

t

i

o

n

[

]


before

(sitting)

after

(sitting)after

(standing)

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Instruction for Action: BGI 804-2

Practical

hints

for

designing

Workplaces,

Working

environment,

Work

organisation

and

Best practice-examples

of ergonomic workplace-design

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Implementation and transferability since 2004

The

redesigned

sewing

workplace

was installed

in more

than

30 German enterprises

.

Redesigning

of 2 up to 160 workplaces

per enterprise.

Deployment

in

Automobile industry,

Toys industry,

Textile industry,

Furniture

industry

and

sheltered

workshops.

This

approach

can

principally

be

transfered

to other

workplaces

or

industries

(e.g. assembly

workplaces).

Ellegast_2011

Humanitarian and Economic Advantages

Example

Fa. MEWA: Mending

of working

clothesBefore: After:

Ergonomic

redesign

of 40 work

places Costs: 1.500

per work

place

(total: appr. 60.000 )

Decrease

of sick

leaves

by

16 % Increase

of productivity

by

appr. 15 % The project will pay for itself within a few months!

Ellegast_2011

Starting point:

Service tasks are increasingly necessary on short flights during ascent and descent phases.

Flight attendants complain of high

physical workload from manoeuvring trolleys in these phases of flight and MSD in general.

High interest in analysing pushing and pulling tasks aboard aircrafts.

Project partners:

Pushing and pulling trolleys aboard aircrafts*

*U. Glitsch, HJ Ottersbach, R. Ellegast, M. Jger, K. Schaub et al., Untersuchung der Belastungen von Flugbegleiterinnen und Flugbegleitern beim Ziehen und Schieben von Trolleys in Flugeugen, BIA-Report

5/2004, HVBG, Sankt Augustin, 2004http://www.hvbg.de/d/bia/pub/rep/rep04/bia0504.html

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Example: Stewardesses

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Laboratory study (flight attendants)

setup:

adjustable

ramp

(12 m)

CUELA motion

analysis

in combination

with

3D force

measurements

(handles

on trolley

and GRF at start)

study

protocol:

25 subjects (flight attendants)

trolley types: full-size, half-size, with variable masses: Full-size (FS)

: 90, 65, 40 kg

Half-size (HS)

: 60, 45, 30 kg

handling: pushing, pulling

floor gradient: 8, 5, 2, 0

No. of trials incl. 3 repetitions: 144

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compression forces L5/S1, calculated with biomechanical model The Dortmunder, (Jger

et al. 1992)

Pushing Pulling

Mass

[kg]

906560454030

C

o

m

p

r

e

s

s

i

o

n

f

o

r

c

e

[

N

]

4000

3000

2000

1000

0

Gradient

0

2

5

8

Mass

[kg]

906560454030

C

o

m

p

r

e

s

s

i

o

n

f

o

r

c

e

[

N

]

4000

3000

2000

1000

0

Half-size

Laboratory study (flight attendants): results

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Research project: Flight attendants

Recommendations for

Work organisation

Trolley design

Manual handling of the trolley, training

http://www.hvbg.de/d/bia/pub/rep/rep04/bia0504.html

Ellegast_2011

Example:

Crane

operator

in a waste

incineration

plant

Initial point:

Crane

operators

in a waste-to-energy-plant

reported

about

complaints

in the

neck and shoulders.

Obiously

identical

crane

operator- workplaces

in two

plants

(P1 and P2)

regarding

seat, equipment, work organisation

and duration

of shift,

but

only

complaints

in P1

Examples of Prevention Ergonomic Workplace Design

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Waste-to-Energy-Plant

Waste

Crane Operator Workplace

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Measurements: Bending of cervical

spine

in P1 and P2

0%

5%

10%

15%

20%

25%

30%

35%

< -

30

-30-

-20

-20-

-10

-10-

0

0-

10

10-

20

20-

30

30-

40

40-

50

50-

60

60-

70

70-

80

80-

90

90-

100

100

- 110

> 110

Winkelbereich ()

A

n

t

e

i

l

a

n

A

r

b

e

i

t

s

z

e

i

t

(

%

)

MHKW 1MHKW 2


P1P2

P

e

r

c

e

n

t

a

g

e

o

f

w

o

r

k

i

n

g

t

i

m

e

angular categories []

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Position of crane operator cabine

P 1: P 2:

Mll-AnlieferungMll-Anlieferung

Preventive

Measure:

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Installation of a new seat

Before after

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Features of the new memory seat

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Comparison: before - after intervention

Seat new Seat old

Cervical spine flexion angle []

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Seat new Seat old

Trunk inclination angle []

Comparison: before - after intervention

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IndividualIndividual BehaviourBehaviour

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Maintenance of electricity wires

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Improvement of individual pre-conditions

Example:

Project RehaBauErgonomic Training

Aims:

Ergonomic

design

at construction

sites

Manuell material handling

techniques

Working

with

handling

aids

motivation

and ergonomic techniques

Senes

of self

of ergonomic techniques

Ellegast_2011

Intensive medical

care

Muscle/muscle

strength

training

Sports/gymnastics, stress relaxation

Training in health

care, nutrition,

physiology

Improvement of individual pre-conditions

Example:

Project RehaBauMedical Training

Foliennummer 1Prevention of Work-Related MSDsExamples Ergonomic Design of Equipment/ToolsExamples Ergonomic Design of Equipment/ToolsExamples Ergonomic Design of Equipment/ToolsExamples Ergonomic Design of Equipment/ToolsExamples Ergonomic Design of Equipment/ToolsUse of supporting toolsFoliennummer 9Use of supporting toolsUse of supporting toolsUse of supporting toolsUse of supporting toolsUse of handling aidsLuggage service at the airportResults luggage serviceBellyloaderResults BellyloaderFoliennummer 19Experimental Technologiesin Luggage HandlingWorkplace DesignWarehouse WorkingWarehouse WorkingFoliennummer 24Examples of Prevention Ergonomic Workplace DesignErgonomic Archetypof a Sewing WorkplaceFeaturesFeaturesComparison: Before and AfterComparison: Before and AfterComparison: Before and AfterInstruction for Action: BGI 804-2Implementation and transferability since 2004Humanitarian and Economic AdvantagesFoliennummer 35Foliennummer 36Laboratory study (flight attendants)Foliennummer 38Research project: Flight attendantsExamples of Prevention Ergonomic Workplace DesignWaste-to-Energy-Plant Crane Operator WorkplaceCrane Operator WorkplaceFoliennummer 44Installation of a new seatFeatures of the new memory seatComparison: before - after interventionComparison: before - after interventionIndividual BehaviourIndividual BehaviourMaintenance of electricity wiresImprovement of individual pre-conditionsImprovement of individual pre-conditions

Documents

03 Prevention in Practice Print Out