LIVRO_HumanFactors

Handbook of Human Factorsand Ergonomics Methods

2005 by CRC Press LLC

CRC PR ESSBoca Raton London New York Washington, D.C.

Neville StantonAlan Hedge

Karel BrookhuisEduardo SalasHal Hendrick

Handbook of Human Factorsand Ergonomics Methods


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The handbook of human factors and ergonomics methods / edited by Neville Stanton [et al.].p. cm.

Includes bibliographical references and index.ISBN 0-415-28700-6 (alk. paper)1. Human engineeringHandbooks, manuals, etc. I. Stanton, Neville, 1960 .

TA166.H275 2004620.8

2dc21 2003012359CIP

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Preface

I must confess to a love of human factors and ergonomics methods. This is a love bordering on obsession.Ever since I was taught how to use hierarchical task analysis (HTA) almost 20 years ago, I have beenhooked. Since that time, I have learned how to use dozens of methods. Each time, it is a mini-adventure.I sometimes wonder if I will understand a new method properly, but when it clicks, I feel euphoric. Ihave also spent a good deal of time training others in the use of methods. This is an extremely rewardingexperience, particularly when a trainee presents an analysis of his/her own that shows a clear grasp ofhow the method works. I have also enjoyed developing some new methods. For example, in collaborationwith Chris Baber at the University of Birmingham, I have developed an error-prediction methodologycalled task analysis for error identication (TAFEI). As with HTA, we have sought to underpin TAFEIwith a theory of human performance. We are still discovering new aspects of the TAFEI analysis, and itgives us both a thrill to see other people reporting their studies using TAFEI.

The inspiration for this handbook came after I wrote A Guide to Methodology in Ergonomics with MarkYoung, which was also published by Taylor & Francis. It was clear to me that, although the human factorsand ergonomics literature is full of references to methods, there are few consistent standards for howthese methods are described and reported. This handbook began in 2000 with a proposal to Taylor &Francis. Fortunately, Tony Moore smiled on this book. With his go-ahead, I contacted experts in each ofthe various domains of ergonomics methods and asked them to edit different sections of the book. I feelvery fortunate that I managed to recruit such an eminent team. To be fair, they did not take muchpersuasion, as they also agreed that this project was a worthwhile undertaking. The next step was to askexperts in the various ergonomics methodologies to summarize their methods in a standardized format.It was a pleasant surprise to see how willingly the contributors responded.

Now, some 4 years after the initial conception, all of the contributions have been gathered and edited.On behalf of the editorial team, I hope that you, the reader, will nd this to be a useful handbook. Wehope that this book will encourage developers of methods to structure the reporting of their methodsin a consistent manner. Equally important, we hope that this handbook will encourage users of themethods to be more adventurous.

Neville A. StantonAugust 2004

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Acknowledgments

On behalf of the editorial team, I would like to thank all of the contributors to this handbook for theirprofessionalism and diligence. I would also like to thank the book commissioning and production teamat Taylor & Francis and CRC Press, especially Tony Moore, Sarah Kramer, Matt Gibbons, Jessica Vakili,Cindy Carelli, and Naomi Lynch.

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Editors

Neville A. Stanton is a professor of human-centered design at Brunel University in the U.K. He has abachelors degree in psychology from the University of Hull as well as master and doctoral degrees inhuman factors from Aston University. Professor Stanton has published over 70 peer-reviewed journalpapers and 7 books on human-centered design. He was a visiting fellow of the Department of Design atCornell University in 1998. He was awarded the Institution of Electrical Engineers Divisional PremiumAward for a paper on engineering psychology and system safety in 1998. The Ergonomics Society awardedhim the Otto Edholm Medal in 2001 for his contribution to basic and applied ergonomics research.Professor Stanton is on the editorial boards of Ergonomics, Theoretical Issues in Ergonomics Science, andthe International Journal of Human Computer Interaction. Professor Stanton is a chartered psychologistand a fellow of the British Psychological Society, a fellow of the Ergonomics Society, and a fellow of theRoyal Society for the Arts.

Eduardo Salas is a professor of psychology at the University of Central Florida, where he also holds anappointment as program director for the Human Systems Integration Research Department at theInstitute for Simulation and Training. He is also the director of UCFs Ph.D. Applied Experimental &Human Factors Program. Previously, he served as a senior research psychologist and head of the TrainingTechnology Development Branch of the Naval Air Warfare Center Training Systems Division for 15 years.During this period, Dr. Salas served as a principal investigator for numerous R&D programs focusingon teamwork, team training, decision making under stress, and performance assessment.

Dr. Salas has coauthored over 200 journal articles and book chapters and has coedited 11 books. Hehas served on the editorial boards of the Journal of Applied Psychology, Personnel Psychology, MilitaryPsychology, Interamerican Journal of Psychology, Applied Psychology: an International Journal, InternationalJournal of Aviation Psychology, Group Dynamics, and the Journal of Organizational Behavior.

His expertise includes helping organizations to foster teamwork, to design and implement teamtraining strategies, to facilitate training effectiveness, to manage decision making under stress, to developperformance measurement tools, and to design learning environments. He is currently working ondesigning tools and techniques to minimize human errors in aviation, law enforcement, and medicalenvironments. He has served as a consultant in a variety of manufacturing settings, pharmaceuticallaboratories, and industrial and governmental organizations. Dr. Salas is a fellow of the AmericanPsychological Association (SIOP and Division 21) and the Human Factors and Ergonomics Society, andhe is a recipient of the Meritorious Civil Service Award from the Department of the Navy. He receivedhis Ph.D. degree (1984) in industrial and organizational psychology from Old Dominion University.

Hal W. Hendrick, Ph.D., CPE, DABFE, is emeritus professor of human factors and ergonomics at theUniversity of Southern California and principal of Hendrick and Associates, an ergonomics and industrialand organizational psychology consulting rm. He is a certied professional ergonomist, diplomate ofthe American Board of Forensic Examiners, and holds a Ph.D. in industrial psychology and an M.S. inhuman factors from Purdue University, with a minor in industrial engineering. He is a past chair of USCsHuman Factors Department, former executive director of the universitys Institute of Safety and SystemsManagement, and a former dean at the University of Denver. He earlier was an associate professor at theU.S. Air Force Academy, where he helped develop the psychology major and developed the CooperativeMS Program in Human Factors with Purdue University. Hal is a past president of the Human Factorsand Ergonomics Society (HFES), the International Ergonomics Association, and the Board of Certicationin Professional Ergonomics. He is a fellow of the International Ergonomics Association (IEA), HFES,

TF1539_book.fm Page ix Wednesday, July 28, 2004 10:36 AM


American Psychological Association, and American Psychological Society. He is a recipient of the USCoutstanding teaching award and both the HFES Jack A. Kraft Innovator Award and Alexander C. Williams,Jr., Design Award. He is the author or coauthor of over 180 professional publications, including 3 books,and editor or coeditor of 11 books. Hal conceptualized and initiated the subdiscipline of macroergonomics.

Alan Hedge is a professor in the Department of Design and Environmental Analysis at Cornell University.His work focuses on the effects of workplace design on the health, comfort, and performance of people.Recent projects have investigated alternative input device design, ergonomic chairs, and other furnitureworkstation elements that can reduce musculoskeletal disorder risk factors. He also researches indoorenvironmental design issues, especially air quality, ventilation, and the sick-building syndrome as wellas ofce lighting and computer-vision syndrome. He has coauthored a book, Keeping Buildings Healthy,25 chapters, and over 150 professional publications. He is active in several professional societies.

Karel Brookhuis studied psychology at Rijksuniversiteit Groningen, specializing in experimental psy-chology, in 1980. He then became a research fellow (Ph.D. student) at the Institute for ExperimentalPsychology, with a specialization in psychophysiology. In 1983 he became a senior researcher at the TrafcResearch Centre, which later merged into the Centre for Environmental and Trafc Psychology, at theUniversity of Groningen. In 1986 he became head of the Department of Biopsychological Aspects ofDriving Behaviour, later renamed the Department of Task Performance and Cognition. In 1994 he wasappointed as a research manager, responsible for the centres research planning and quality control. Afterthe centre was closed on January 1, 2000, he became associate professor (UHD) in the Department ofExperimental and Work Psychology. Since 2001, Brookhuis has served as a part-time full professor at theSection of Transport Policy and Logistics of the Technical University of Delft.

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Contributors

Torbjrn kerstedtNational Institute for Psychosocial

Factors and HealthStockholm, Sweden

W.G. AllreadOhio State UniversityInstitute for ErgonomicsColumbus, OH

Dee H. AndrewsU.S. Air Force Research LaboratoryWarghter Training Research

DivisionMesa, AZ

John AnnettUniversity of WarwickDepartment of PsychologyCoventry, U.K.

Amelia A. ArmstrongKlein Associates Inc.Fairborn, OH

Christopher BaberUniversity of BirminghamComputing EngineeringBirmingham, U.K.

David P. BakerAmerican Institutes for ResearchWashington, D.C.

Natale BatteviEPM-CEMOCMilan, Italy

J. Matthew BeaubienAmerican Institutes for ResearchWashington, D.C.

Artem BelopolskyUniversity of IllinoisDepartment of PsychologyChampaign, IL

Jennifer BlumeNational Space BiomedicalResearch InstituteHouston, TX

Gunnar BorgStockholm UniversityDepartment of PsychologyStockholm, Sweden

Wolfram BoucseinUniversity of WuppertalPhysiological PsychologyWuppertal, Germany

Clint A. BowersUniversity of Central FloridaDepartment of PsychologyOrlando, FL

Peter R. BoyceRensselaer Polytechnic InstituteLighting Research CenterTroy, NY

Karel A. BrookhuisUniversity of GroningenExperimental & Work PsychologyGroningen, the Netherlands

Ogden Brown, Jr.University of DenverDenver, CO

Peter BuckleUniversity of SurreyRobens Center for Health

ErgonomicsGuildford, U.K.

C. Shawn BurkeUniversity of Central FloridaInstitute for Simulation & TrainingOrlando, FL

Pascale CarayonUniversity of WisconsinCenter for Quality & Productivity

ImprovementMadison, WI

Daniela ColombiniEPM-CEMOCMilan, Italy

Nancy J. CookeArizona State University EastApplied Psychology ProgramMesa, AZ

Lee CooperUniversity of BirminghamComputing EngineeringBirmingham, U.K.

Nigel CorlettUniversity of NottinghamInstitute for Occupational

ErgonomicsNottingham, U.K.

Dana M. CostarAmerican Institutes for ResearchWashington, D.C.

Pamela DaltonMonell Chemical Senses CenterPhiladelphia, PA

Rene E. DeRouinUniversity of Central FloridaInstitute for Simulation & TrainingOrlando, FL

Dick de WaardUniversity of GroningenExperimental & Work PsychologyGroningen, the Netherlands

David F. DingesUniversity of PennsylvaniaSchool of MedicinePhiladelphia, PA

James E. DriskellFlorida Maxima CorporationWinter Park, FL

Robin Dunkin-ChadwickNIOSHDivision of Applied Research

& TechnologyCincinnati, OH

J.R. EasterAegis Research CorporationPittsburgh, PA

W.C. ElmAegis Research CorporationPittsburgh, PA

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Eileen B. EntinAptima, Inc.Wodburn, MA

Elliot E. EntinAptima, Inc.Wodburn, MA

Gary W. EvansCornell UniversityDepartment of Design &

Environmental AnalysisIthaca, NY

Stephen M. FioreUniversity of Central FloridaInstitute for Simulation & TrainingOrlando, FL

M.M. FleischerUniversity of Southern CaliforniaLos Angeles, CA

Jennifer E. FowlkesChi Systems, Inc.Orlando, FL

Philippe GeslinInstitut National de la Recherche

Agronomique (INRA)Toulouse, France andUniversit de Neuchtel Institut

dethnologieNeuchtel, Switzerland

Matthias GbelBerlin University of TechnologyDepartment of Human Factors

Engineering and Product Ergonomics

Berlin, Germany

Thad GodishBall State UniversityDepartment of Natural ResourcesMuncie, IN

Gerald F. GoodwinU.S. Army Research InstituteAlexandria, VA

Paul GrossmanFreiburg Institute for Mindfulness

ResearchFreiburg, Germany

J.W. GualtieriAegis Research CorporationPittsburgh, PA

Bianka B. HahnKlein Associates Inc.Fairborn, OH

Thomas R. HalesNIOSHDivision of Applied Research


George HavenithLoughborough UniversityDepartment of Human SciencesLoughborough, U.K.

Alan HedgeCornell UniversityDepartment of Design &

Environmental AnalysisIthaca, NY

Hal W. HendrickHendrick and AssociatesGreenwood Village, CO

Sue HignettLoughborough UniversityDepartment of Human SciencesLoughborough, U.K.

Vincent H. HildebrandtTNO Work & EmploymentHoofddorp, the NetherlandsandBody@Work Research Center on

Physical Activity, Work and Health TNO Vumc

Amsterdam, the Netherlands

Hermann HinrichsUniversity of MagdeburgClinic for NeurologyMagdeburg, Germany

Peter HoonakkerUniversity of WisconsinCenter for Quality & Productivity

ImprovementMadison, WI

Karen JacobsBoston University Programs

in Occupational TherapyBoston, MA

Florian JentschUniversity of Central FloridaDepartment of PsychologyOrlando, FL

R.F. Soames JobUniversity of SydneySchool of PsychologySydney, Australia

Debra G. JonesSA Technologies, Inc.Marietta, GA

David B. KaberNorth Carolina State UniversityDepartment of Industrial

EngineeringRaleigh, NC

Jussi KantolaUniversity of LouisvilleCenter for Industrial ErgonomicsLouisville, KY

Waldemar KarwowskiUniversity of LouisvilleCenter for Industrial ErgonomicsLouisville, KY

Kristina KemmlertNational Institute for Working LifeSolna, Sweden

Mark KirbyUniversity of HudderseldSchool of Computing and

EngineeringHudderseld, U.K.

Gary KleinKlein Associates Inc.Fairborn, OH

Brian M. KleinerVirginia Polytechnical Institute

and State UniversityGrado Department of Industrial

and Systems EngineeringBlacksburg, VA

David W. KlingerKlein Associates Inc.Fairborn, OH

Arthur F. KramerUniversity of IllinoisDepartment of PsychologyChampaign, IL

Guangyan LiHuman Engineering LimitedBristol, U.K.

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Jean MacMillanAptima, Inc.Wodburn, MA

Ann MajchrzakUniversity of Southern CaliforniaMarshall School of BusinessLos Angeles, CA

Melissa M. MallisNASA Ames Research CenterFatigue Countermeasures GroupMoffett Field, CA

W.S. MarrasOhio State UniversityInstitute for ErgonomicsColumbus, OH

Philip MarsdenUniversity of HudderseldSchool of Computing and

EngineeringHudderseld, U.K.

Laura Martin-MilhamUniversity of Central FloridaInstitute for Simulation & TrainingOrlando, FL

Lorraine E. MaxwellCornell UniversityDesign & Environmental AnalysisIthaca, NY

Lynn McAtamneyCOPE Occupational Health and

Ergonomics Services Ltd.Nottingham, U.K.

Olga MenoniEPM-CEMOCMilan, Italy

J. MokrayUniversity of Southern CaliforniaLos Angeles, CA

J. Steven MooreTexas A&M UniversitySchool of Rural Public HealthBryan, TX

Lambertus (Ben) J.M. MulderUniversity of GroningenExperimental & Work PsychologyGroningen, the Netherlands

Brian MullenSyracuse UniversitySyracuse, NY

Mitsuo NagamachiHiroshima International UniversityHiroshima, Japan

Leah NewmanPennsylvania State UniversityThe Harold & Inge Marcus

Department of Industrial & Manufacturing Engineering

University Park, PA

Enrico OcchipintiEPM-CEMOCMilan, Italy

Michael J. PaleyAptima, Inc.Wodburn, MA

Daniela PancieraEPM-CEMOCMilan, Italy

Brian PeacockNational Space Biomedical

Research InstituteHouston, TX

S.S. PotterAegis Research CorporationPittsburgh, PA

Heather A. PriestUniversity of Central FloridaInstitute for Simulation & TrainingOrlando, FL

Renate RauUniversity of Technology Occupational Health PsychologyDresden, Germany

Mark S. ReaRensselaer Polytechnic InstituteLighting Research CenterTroy, NY

Maria Grazia RicciEPM-CEMOCMilan, Italy

Hannu RintamkiOulu Regional Institute of

Occupational HealthOulu, Finland

Michelle M. RobertsonLiberty Mutual Research Institute

for SafetyHopkinton, MA

Suzanne H. RodgersConsultant in ErgonomicsRochester, NY

D. RoitmanUniversity of Southern CaliforniaLos Angeles, CA

E.M. RothRoth Cognitive EngineeringBrookline, MA

Eduardo SalasUniversity of Central FloridaDepartment of PsychologyOrlando, FL

Steven L. SauterNIOSHDivision of Applied Research


Steven M. ShopeUS Positioning Group, LLCMesa, AZ

Monique SmeetsUtrecht University Department of Social SciencesUtrecht, the Netherlands

Tonya L. Smith-JacksonVirginia Polytechnic Institute and

State UniversityGrado Department of Industrial

and Systems EngineeringBlacksburg, VA

Kimberly A. Smith-JentschUniversity of Central FloridaDepartment of PsychologyOrlando, FL

Stover H. SnookHarvard School of Public HealthBoston, MA

Neville A. StantonBrunel UniversitySchool of EngineeringLondon, U.K.

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Naomi G. SwansonNIOSHDivision of Applied Research


Jrn ToftumTechnical University of DenmarkInternational Centre for Indoor

Environment & EnergyLyngby, Denmark

Rendell R. TorresRensselaer Polytechnic InstituteSchool of ArchitectureTroy, NY

Susan VallanceJohnson EngineeringHouston, TX

Gordon A. VosTexas A&M UniversitySchool of Rural Public HealthBryan, TX

Guy WalkerBrunel UniversitySchool of EngineeringLondon, U.K.

Donald E. WassermanUniversity of TennesseeInstitute for the Study of Human

VibrationKnoxville, TN

Jack F. WassermanUniversity of TennesseeInstitute for the Study of Human


Thomas R. WatersNIOSHDivision of Applied Research


Christopher D. WickensUniversity of Illinois at Urbana-

ChampaignInstitute of AviationAviation Human Factors DivisionSavoy, IL

Cornelis J.E. WientjesNATO Research & Technology

AgencyBrussels, Belgium

David WilderUniversity of TennesseeInstitute for the Study of Human


Mark S. YoungUniversity of New South WalesDepartment of AviationSydney, Australia

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Contents

1 Human Factors and Ergonomics Methods Neville A. Stanton . . . . . . . . . 1-1

Physical Methods

2 Physical Methods Alan Hedge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

3 PLIBEL The Method Assigned for Identication of Ergonomic Hazards Kristina Kemmlert . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

4 Musculoskeletal Discomfort Surveys Used at NIOSHSteven L. Sauter, Naomi G. Swanson, Thomas R. Waters, Thomas R. Hales, and Robin Dunkin-Chadwick . . . . . . . . . . . . . . . . . . . . 4-1

5 The Dutch Musculoskeletal Questionnaire (DMQ) Vincent H. Hildebrandt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

6 Quick Exposure Checklist (QEC) for the Assessment of Workplace Risks for Work-Related Musculoskeletal Disorders (WMSDs) Guangyan Li and Peter Buckle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

7 Rapid Upper Limb Assessment (RULA) Lynn McAtamney and Nigel Corlett . . . 7-1

8 Rapid Entire Body Assessment Lynn McAtamney and Sue Hignett . . . . . 8-1

9 The Strain Index J. Steven Moore and Gordon A. Vos . . . . . . . . . . . . . . . . 9-1

10 Posture Checklist Using Personal Digital Assistant (PDA) Technology Karen Jacobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

11 Scaling Experiences during Work: Perceived Exertion and Difculty Gunnar Borg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1

12 Muscle Fatigue Assessment: Functional Job Analysis Technique Suzanne H. Rodgers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1

13 Psychophysical Tables: Lifting, Lowering, Pushing, Pulling, and Carrying Stover H. Snook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1

14 Lumbar Motion Monitor W.S. Marras and W.G. Allread . . . . . . . . . . . . . 14-1

15 The Occupational Repetitive Action (OCRA) Methods: OCRA Index and OCRA Checklist Enrico Occhipinti and Daniela Colombini . . . . . . . . . . . 15-1

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16 Assessment of Exposure to Manual Patient Handling in Hospital Wards: MAPO Index (Movement and Assistance of Hospital Patients) Olga Menoni, Maria Grazia Ricci, Daniela Panciera, and Natale Battevi 16-1

Psychophysiological Methods

17 Psychophysiological Methods Karel A. Brookhuis . . . . . . . . . . . . . . . . . . . 17-1

18 Electrodermal Measurement Wolfram Boucsein . . . . . . . . . . . . . . . . . . . . 18-1

19 Electromyography (EMG) Matthias Gbel . . . . . . . . . . . . . . . . . . . . . . . . 19-1

20 Estimating Mental Effort Using Heart Rate and Heart Rate Variability Lambertus (Ben) J.M. Mulder, Dick de Waard, and Karel A. Brookhuis . . . . . . . 20-1

21 Ambulatory EEG Methods and Sleepiness Torbjrn kerstedt . . . . . . . . 21-1

22 Assessing Brain Function and Mental Chronometry with Event-Related Potentials (ERP) Arthur F. Kramer and Artem Belopolsky . . . . . . . . . . . . . 22-1

23 MEG and fMRI Hermann Hinrichs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23-1

24 Ambulatory Assessment of Blood Pressure to Evaluate Workload Renate Rau . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24-1

25 Monitoring Alertness by Eyelid Closure Melissa M. Mallis and David F. Dinges . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-1

26 Measurement of Respiration in Applied Human Factors and Ergonomics Research Cornelis J.E. Wientjes and Paul Grossman . . . . . . . 26-1

Behavioral and Cognitive Methods

27 Behavioral and Cognitive Methods Neville A. Stanton . . . . . . . . . . . . . 27-1

28 Observation Neville A. Stanton, Christopher Baber, and Mark S. Young . . . 28-1

29 Applying Interviews to Usability AssessmentMark S. Young and Neville A. Stanton . . . . . . . . . . . . . . . . . . . . . . . . . . . 29-1

30 Verbal Protocol Analysis Guy Walker . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-1

31 Repertory Grid for Product Evaluation Christopher Baber . . . . . . . . . . . 31-1

32 Focus Groups Lee Cooper and Christopher Baber . . . . . . . . . . . . . . . . . . 32-1

33 Hierarchical Task Analysis (HTA) John Annett . . . . . . . . . . . . . . . . . . . . . 33-1

34 Allocation of Functions Philip Marsden and Mark Kirby . . . . . . . . . . . . 34-1

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35 Critical Decision Method Gary Klein and Amelia A. Armstrong . . . . . . . 35-1

36 Applied Cognitive Work Analysis (ACWA) W.C. Elm, E.M. Roth, S.S. Potter, J.W. Gualtieri, and J.R. Easter . . . . . . . . . . . . . . . . . . . . . . . . 36-1

37 Systematic Human Error Reduction and Prediction Approach (SHERPA) Neville A. Stanton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37-1

38 Task Analysis for Error Identication Neville A. Stanton andChristopher Baber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38-1

39 Mental Workload Mark S. Young and Neville A. Stanton . . . . . . . . . . . . 39-1

40 Multiple Resource Time Sharing Models Christopher D. Wickens . . . . . . 40-1

41 Critical Path Analysis for Multimodal Activity Christopher Baber . . . . . 41-1

42 Situation Awareness Measurement and the Situation Awareness Global Assessment Technique Debra G. Jones and David B. Kaber . . . . . 42-1

Team Methods

43 Team Methods Eduardo Salas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43-1

44 Team Training Eduardo Salas and Heather A. Priest . . . . . . . . . . . . . . . . 44-1

45 Distributed Simulation Training for Teams Dee H. Andrews . . . . . . . . . 45-1

46 Synthetic Task Environments for Teams: CERTTs UAV-STE Nancy J. Cooke and Steven M. Shope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46-1

47 Event-Based Approach to Training (EBAT) Jennifer E. Fowlkes and C. Shawn Burke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47-1

48 Team Building Eduardo Salas, Heather A. Priest, and Rene E. DeRouin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48-1

49 Measuring Team Knowledge Nancy J. Cooke . . . . . . . . . . . . . . . . . . . . . . 49-1

50 Team Communications Analysis Florian Jentsch and Clint A. Bowers . . . 50-1

51 Questionnaires for Distributed Assessment of Team Mutual Awareness Jean MacMillan, Michael J. Paley, Eileen B. Entin, and Elliot E. Entin . . . 51-1

52 Team Decision Requirement Exercise: Making Team DecisionRequirements Explicit David W. Klinger and Bianka B. Hahn . . . . . . . . . 52-1

53 Targeted Acceptable Responses to Generated Events or Tasks (TARGETs) Jennifer E. Fowlkes and C. Shawn Burke . . . . . . . . . . . . . . . . . . . . . . . . . . 53-1

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54 Behavioral Observation Scales (BOS) J. Matthew Beaubien, Gerald F. Goodwin, Dana M. Costar, David P. Baker, and Kimberly A. Smith-Jentsch . . . . . . . 54-1

55 Team Situation Assessment Training for Adaptive Coordination Laura Martin-Milham and Stephen M. Fiore . . . . . . . . . . . . . . . . . . . . . . . 55-1

56 Team Task Analysis C. Shawn Burke . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56-1

57 Team Workload Clint A. Bowers and Florian Jentsch . . . . . . . . . . . . . . . . 57-1

58 Social Network Analysis James E. Driskell and Brian Mullen . . . . . . . . . . 58-1

Environmental Methods

59 Environmental Methods Alan Hedge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59-1

60 Thermal Conditions Measurement George Havenith . . . . . . . . . . . . . . . . 60-1

61 Cold Stress Indices Hannu Rintamki. . . . . . . . . . . . . . . . . . . . . . . . . . . . 61-1

62 Heat Stress Indices Alan Hedge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62-1

63 Thermal Comfort Indices Jrn Toftum . . . . . . . . . . . . . . . . . . . . . . . . . . . 63-1

64 Indoor Air Quality: Chemical Exposures Alan Hedge . . . . . . . . . . . . . . . 64-1

65 Indoor Air Quality: Biological/Particulate-Phase ContaminantExposure Assessment Methods Thad Godish . . . . . . . . . . . . . . . . . . . . . . . 65-1

66 Olfactometry: The Human Nose as Detection Instrument Pamela Dalton and Monique Smeets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66-1

67 The Context and Foundation of Lighting Practice Mark S. Rea and Peter R. Boyce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67-1

68 Photometric Characterization of the Luminous Environment Mark S. Rea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68-1

69 Evaluating Ofce Lighting Peter R. Boyce . . . . . . . . . . . . . . . . . . . . . . . . . 69-1

70 Rapid Sound-Quality Assessment of Background Noise Rendell R. Torres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70-1

71 Noise Reaction Indices and Assessment R.F. Soames Job . . . . . . . . . . . . 71-1

72 Noise and Human Behavior Gary W. Evans and Lorraine E. Maxwell . . 72-1

73 Occupational Vibration: A Concise Perspective Jack F. Wasserman, Donald E. Wasserman, and David Wilder . . . . . . . . . . . . . . . . . . . . . . . . . . 73-1

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74 Habitability Measurement in Space Vehicles and Earth Analogs Brian Peacock, Jennifer Blume, and Susan Vallance . . . . . . . . . . . . . . . . . 74-1

Macroergonomic Methods

75 Macroergonomic Methods Hal W. Hendrick . . . . . . . . . . . . . . . . . . . . . . 75-1

76 Macroergonomic Organizational Questionnaire Survey (MOQS) Pascale Carayon and Peter Hoonakker . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76-1

77 Interview Method Leah Newman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77-1

78 Focus Groups Leah Newman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78-1

79 Laboratory Experiment Brian M. Kleiner . . . . . . . . . . . . . . . . . . . . . . . . . 79-1

80 Field Study and Field Experiment Hal W. Hendrick . . . . . . . . . . . . . . . . . 80-1

81 Participatory Ergonomics (PE) Ogden Brown, Jr. . . . . . . . . . . . . . . . . . . . 81-1

82 Cognitive Walk-Through Method (CWM) Tonya L. Smith-Jackson . . . . . 82-1

83 Kansei Engineering Mitsuo Nagamachi . . . . . . . . . . . . . . . . . . . . . . . . . . . 83-1

84 HITOP Analysis Ann Majchrzak, M.M. Fleischer, D. Roitman, and J. Mokray . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84-1

85 TOP-Modeler Ann Majchrzak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85-1

86 The CIMOP System Waldemar Karwowski and Jussi Kantola . . . . . . . . 86-1

87 Anthropotechnology Philippe Geslin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87-1

88 Systems Analysis Tool (SAT) Michelle M. Robertson. . . . . . . . . . . . . . . . . 88-1

89 Macroergonomic Analysis of Structure (MAS) Hal W. Hendrick . . . . . . . 89-1

90 Macroergonomic Analysis and Design (MEAD) Brian M. Kleiner . . . . . . 90-1

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1-1

1Human Factors and

Ergonomics Methods

1.1 Aims of the Handbook ..................................................... 1-11.2 Layout of the Handbook .................................................. 1-31.3 Layout of Each Entry ........................................................ 1-51.4 Other Methods Books....................................................... 1-51.5 Challenges for Human Factors and Ergonomics

Methods ............................................................................. 1-6References ..................................................................................... 1-8

1.1 Aims of the Handbook

The main aim of this handbook is to provide a comprehensive, authoritative, and practical account ofhuman factors and ergonomics methods. It is intended to encourage people to make full use of humanfactors and ergonomics methods in system design. Research has suggested that even professional ergon-omists tend to restrict themselves to two or three of their favorite methods, despite variations in theproblems that they address (Baber and Mirza, 1988; Stanton and Young, 1998). If this book leads peopleto explore human factors and ergonomics methods that are new to them, then it will have achieved its goal.

The page constraints of this handbook meant that coverage of the main areas of ergonomics had tobe limited to some 83 methods. The scope of coverage, outlined in Table 1.1, was determined by whatergonomists do.

From these denitions, it can be gleaned that the domain of human factors and ergonomics includes:

Human capabilities and limitations Humanmachine interaction Teamwork Tools, machines, and material design Environmental factors Work and organizational design

These denitions also put an emphasis (sometimes implicit) on analysis of human performance, safety,and satisfaction. It is no wonder, then, that human factors and ergonomics is a discipline with a strongtradition in the development and application of methods.

Hancock and Diaz (2002) argue that, as a scientic discipline, ergonomics holds the moral high ground,with the aim of bettering the human condition. They suggest that this may be at conict with other aimsof improving system effectiveness and efciency. No one would argue with the aims of improved comfort,satisfaction, and well-being, but the drawing of boundaries between the improvements for individualsand improvements for the whole system might cause some heated debate. Wilson (1995) suggests thatthe twin interdependent aims of ergonomics might not be easy to resolve, but ergonomists have a dutyto both individual jobholders and the employing organization. Ethical concerns about the issue of divided

Neville A. StantonBrunel University

TF1539_book.fm Page 1 Wednesday, July 28, 2004 10:36 AM


1-2 Handbook of Human Factors and Ergonomics Methods

responsibilities might only be dealt with satisfactorily by making it clear to all concerned where onesloyalties lie.

The International Encyclopedia of Human Factors and Ergonomics (Karwowski, 2001) has an entiresection devoted to methods and techniques. Many of the other sections of the encyclopedia also providereferences to, if not actual examples of, ergonomics methods. In short, the importance of human factorsand ergonomics methods cannot be overstated. These methods offer the ergonomist a structuredapproach to the analysis and evaluation of design problems. The ergonomist's approach can be describedusing the scientist-practitioner model. As a scientist, the ergonomist is:

Extending the work of others Testing theories of humanmachine performance Developing hypotheses Questioning everything Using rigorous data-collection and data-analysis techniques Ensuring repeatability of results Disseminating the nding of studies

As a practitioner, the ergonomist is:

Addressing real-world problems Seeking the best compromise under difcult circumstances Looking to offer the most cost-effective solution Developing demonstrators and prototype solutions Analyzing and evaluating the effects of change Developing benchmarks for best practice Communicating ndings to interested parties

Most ergonomists will work somewhere between the poles of scientist and practitioner, varying theemphasis of their approach depending upon the problems that they face. Human factors and ergonomistmethods are useful in the scientist-practitioner model because of the structure, and the potential forrepeatability, that they offer. There is an implicit guarantee in the use of methods that, provided they are

TABLE 1.1 Denitions of Human Factors and Ergonomics

Author Denition of Human Factors and Ergonomics

Murrell, 1965 the scientic study of the relationship between man and his working environment. In this sense, the term environment is taken to cover not only the ambient environment in which he may work but also his tools and materials, his methods of work and the organization of the work, either as an individual or within a working group. All these are related to the nature of man himself; to his abilities, capacities and limitations.

Grandjean, 1980 is a study of mans behavior in relation to his work. The object of this research is man at work in relation to his spatial environmentthe most important principle of ergonomics: Fitting the task to the man. Ergonomics is interdisciplinarian: it bases its theories on physiology, psychology, anthropometry, and various aspects of engineering.

Meister, 1989 is the study of how humans accomplish work-related tasks in the context of human-machine system operation and how behavioral and nonbehavioral variables affect that accomplishment.

Sanders and McCormick, 1993 discovers and applies information about human behavior, abilities, limitations, and other characteristics to the design of tools, machines, tasks, jobs, and environments for productive, safe, comfortable, and effective human use.

Hancock, 1997 is that branch of science which seeks to turn humanmachine antagonism into humanmachine synergy.

Source: Dempsey, P.G., Wolgalter, M.S., and Hancock, P.A. (2000), Theor. Issues Ergonomics Sci., 1, 310. With permission.



Human Factors and Ergonomics Methods 1-3

used properly, they will produce certain types of useful products. It has been suggested that human factorsand ergonomist methods are a route to making the discipline accessible to all (Diaper, 1989; Wilson,1995). Despite the rigor offered by methods, however, there is still plenty of scope for the role ofexperience. Stanton and Annett (2000) summarized the most frequently asked questions raised by usersof ergonomics methods as follows:

How deep should the analysis be? Which methods of data collection should be used? How should the analysis be presented? Where is the use of the method appropriate? How much time and effort does each method require? How much and what type of expertise is needed to use the method? What tools are there to support the use of the method? How reliable and valid is the method?

It is hoped that the contributions to this book will help answer some of those questions.

1.2 Layout of the Handbook

The handbook is divided into six sections, each section representing a specialized eld of ergonomicswith a representative selection of associated methods. The sequence of the sections and a brief descriptionof their contents are presented in Table 1.2. The six sections are intended to represent all facets of humanfactors and ergonomics in systems analysis, design, and evaluation. Three of the methods sections(Sections I through III) are concerned with the individual person and his or her interaction with theworld (i.e., physical methods, psychophysiological methods, and behavioralcognitive methods). One ofthe methods sections (Section IV) is concerned with the social groupings and their interaction with theworld (i.e., team methods). Another of the methods sections (Section V) is concerned with the effect

TABLE 1.2 Description of the Contents of the Six Methods Sections of the Handbook

Methods Sections in Handbook Brief Description of Contents

Section I: Physical Methods This section deals with the analysis and evaluation of musculoskeletal factorsThe topics include: measurement of discomfort, observation of posture, analysis

of workplace risks, measurement of work effort and fatigue, assessing lower back disorder, and predicting upper-extremity injury risks

Section II: Psychophysiological Methods

This section deals with the analysis and evaluation of human psychophysiologyThe topics include: heart rate and heart rate variability, event-related potentials,

galvanic skin response, blood pressure, respiration rate, eyelid movements, and muscle activity

Section III: BehavioralCognitive Methods

This section deals with the analysis and evaluation of people, events, artifacts, and tasks

The topics include: observation and interviews, cognitive task analysis methods, human error prediction, workload analysis and prediction, and situational awareness

Section IV: Team Methods This section deals with the analysis and evaluation of teamsThe topics include: team training and assessment requirements, team building,

team assessment, team communication, team cognition, team decision making, and team task analysis

Section V: Environmental Methods This section deals with the analysis and evaluation of environmental factorsThe topics include: thermal conditions, indoor air quality, indoor lighting, noise

and acoustic measures, vibration exposure, and habitabilitySection VI: Macroergonomics

MethodsThis section deals with the analysis and evaluation of work systemsThe topics include: organizational and behavioral research methods,

manufacturing work systems, anthropotechnology, evaluations of work system intervention, and analysis of the structure and processes of work systems




that the environment has on people (i.e., environmental methods). Finally, the last of the methods sections(Section VI) is concerned with the overview of work systems (i.e., macroergonomics methods). Thesesets of methods are framed by the classic onion-layer analysis model, working from the individual, tothe team, to the environment, to the work system. In theoretical system terms, the level of analysis canbe set at all four levels, or it may focus at only one or two levels. The system boundaries will dependupon the purpose of the analysis or evaluation.

Each section of the handbook begins with an introduction written by the editor of that section. Theintroduction provides a brief overview of the eld along with a description of the methods covered inthe sequence that they appear. The editor responsible for that section determined the contents of eachsection. Their brief was to provide a representative set of contemporary methods that they felt were usefulfor ergonomic analyses and evaluation. Given the restrictions on page length for the handbook, this wasa tall order. Nonetheless, the nal set of chapters does present a good overview of contemporary devel-opments in ergonomics methods and serves as a useful handbook. Some of the methods in Section V,Environmental Methods, do not follow the template approach, especially in lighting and thermal meth-ods. This is because there is no single method that is favored or complete. Therefore, it would be verymisleading to select any single method.

Wilson (1995) divides ergonomics methods into ve basic types of design data:

1. Methods for collecting data about people (e.g., collection of data on physical, physiological, andpsychological capacities)

2. Methods used in system development (e.g., collection of data on current and proposed systemdesign)

3. Methods to evaluate humanmachine system performance (e.g., collection of data on quantitativeand qualitative measures)

4. Methods to assess the demands and effects on people (e.g., collection of data on short-term andlonger-term effects on the well-being of the person performing the tasks being analyzed)

5. Methods used in the development of an ergonomics management program (e.g., strategies forsupporting, managing, and evaluating sustainable ergonomics interventions).

These ve basic types of design data have been put into a table to help in assessing their relationshipwith the six methods section in this book, as shown in Table 1.3.

As Table 1.3 shows, the methods in this handbook cover all of the ve basic types of design data. Thedarker shading represents a primary source of design data, and the lighter shading represents a secondary,or contributory, source of design data.

TABLE 1.3 Mapping Wilson's Five Basic Types of Design Data onto the Method Sections in the Handbook

Data about People

SystemsDevelopment

HumanMachine Performance

Demand and Effects on

People

ErgonomicsManagement

Programs

Physical

Psychophysiological

BehavioralCognitiveTeam

Environmental

Macroergonomics




1.3 Layout of Each Entry

The layout of each chapter is standardized to assist the reader in using the handbook. This approach wastaken so that the reader would easily be able to locate the relevant information about the method. All ofthe information is given in a fairly brief form, and the reader is encouraged to consult other texts andpapers for more background research on the methods and more case examples of application of themethods. The standard layout is described in Table 1.4.

The standardized approach should support quick reference to any particular method and encouragethe readers to browse through potential methods before tackling the particular problem that they face.It is certainly the intention of this text to encourage the use of ergonomics methods, provided that suitablesupport and mentoring is in place to ensure that the methods are used properly.

1.4 Other Methods Books

The number of methods books continues to grow, making it impossible to keep up with every text andto choose or recommend a single method book for all purposes. The best advice is to select two or threethat meet most of your needs, unless you can afford to stock a comprehensive library. There tend to befour types of methods books. The rst type is the specialized and single authored, such as HierarchicalTask Analysis (Shepherd, 2001). The second type of book is specialized and edited, such as Task Analysis(Annett and Stanton, 2000). The third type of book is generalized and edited, such as Evaluation ofHuman Work (Wilson and Corlett, 1995). The fourth kind of book is generalized and authored, such asA Guide to Methodology in Ergonomics (Stanton and Young, 1999). This classication in presented inTable 1.5.

TABLE 1.4 Layout of the Chapters in the Handbook

Section Chapter Description of Contents

Name and acronym Name of the method and its associated acronymAuthor name and afliation Names and afliations of the authorsBackground and applications Introduces the method, its origins and development, and applicationsProcedure and advice Describes the procedure for applying the method and general points of expert adviceAdvantages A list or description of the advantages associated with using the methodDisadvantages A list or description of the disadvantages associated with using the methodExample Provides one or more examples of the application to show the output of the methodRelated methods Lists any closely related methods, particularly if the input comes from another method

or the method's output feeds into another methodStandards and regulations Lists any national or international standards or regulations that have implications for

the use of the methodApproximate training and

application timesProvides estimates of the training and application times to give the reader an idea of

the commitmentReliability and validity Cites any evidence on the reliability or validity of the methodTools needed A description of the tools, devices, and software needed to carry out the methodReferences A bibliographic list of recommended further reading on the method and the

surrounding topic area

TABLE 1.5 Methods Books Taxonomy

Specialized Generalized

Authored Hierarchical Task Analysisby Andrew Shepherd

A Guide to Methodology in Ergonomicsby Neville Stanton and Mark Young

Edited Task Analysisby John Annett and Neville Stanton

Evaluation of Human Workby John Wilson and Nigel Corlett




An analysis of 15 other methods books published over the past decade shows the range of edited andauthored texts in this eld, the length of the books, and their coverage. Any of these books couldcomplement this handbook. Where they differ is in their scope (e.g., either being focused on humancom-puter interaction or more generalized) and their coverage (e.g., either covering one or two areas ofergonomics or having more general coverage). A summary of the texts is presented in Table 1.6.

As Table 1.6 indicates, there is certainly no shortage of ergonomics methods texts. Selection of theappropriate text will depend on the intended scope and coverage of the ergonomics intervention required.

1.5 Challenges for Human Factors and Ergonomics Methods

Ergonomics science abounds with methods and models for analyzing tasks, designing work, predictingperformance, collecting data on human performance and interaction with artifacts and the environmentin which this interaction takes place. Despite the plethora of methods, there are several signicantchallenges faced by the developers and users of ergonomics methods. These challenges include:

Developing methods that integrate with other methods Linking methods with ergonomics theory Making methods easy to use

TABLE 1.6 Overview of Other Methods Books

Author(s) Title Edited/Authored Date (ed.) Pages Coverage a

Annett and Stanton

Task Analysis Edited 2000(1st)

242 B/C, T

Corlett and Clarke

The Ergonomics of Workspace and Machines

Edited 1995(2nd)

128 P, B/C

Diaper and Stanton

Task Analysis in HumanComputer Interaction

Edited 2004(1st)

760 B/C, T

Helender et al. Handbook of HumanComputer Interaction

Edited 1997(2nd)

1582 P, B/C, T, M

Jacko and Sears The HumanComputer Interaction Handbook

Edited 2003(1st)

1277 P, B/C, T, M

Jordan et al. Usability Evaluation in Industry Edited 1996(1st)

252 P, B/C

Karwowski and Marras

The Occupational Ergonomics Handbook

Edited 1999(1st)

2065 P, PP, B/C, T, E, M

Kirwan A Guide to Practical Human Reliability Assessment

Authored 1994(1st)

592 B/C

Kirwan and Ainsworth

A Guide to Task Analysis Edited 1992(1st)

417 B/C

Salvendy Handbook of Human Factors and Ergonomics

Edited 1997(2nd)

2137 P, PP, B/C, T, E, M

Schraagen et al. Cognitive Task Analysis Edited 1999(1st)

B/C

Seamster et al. Applied Cognitive Task Analysis Authored 1997(1st)

338 B/C

Shepherd Hierarchical Task Analysis Authored 2001(1st)

270 B/C

Stanton Human Factors in Consumer Products

Edited 1998(1st)

287 P, B/C

Stanton and Young

A Guide to Methodology in Ergonomics

Authored 1999(1st)

150 B/C

Wilson and Corlett

Evaluation of Human Work Edited 1995(2nd)

1134 P, PP, B/C, T, E, M

a Key to coverage: physical methods (P), psychophysiological methods (PP), behavioral and cognitive methods (B/C), teammethods (T), environmental methods (E), macroergonomic methods (M).




Providing evidence of reliability and validity Showing that the methods lead to cost-effective interventions Encouraging ethical application of methods

Annett (2002) questions the relative merits for construct and criterion-referenced validity in the devel-opment of ergonomics theory. He distinguishes between construct validity (how acceptable the underlyingtheory is), predictive validity (the usefulness and efciency of the approach in predicting the behavior ofan existing or future system), and reliability (the repeatability of the results). Investigating the matter further,Annett identies a dichotomy of ergonomics methods: analytical methods and evaluative methods. Annettargues that analytical methods (i.e., those methods that help the analyst gain an understanding of themechanisms underlying the interaction between human and machines) require construct validity, whereasevaluative methods (i.e., those methods that estimate parameters of selected interactions between humanand machines) require predictive validity. This distinction is made in Table 1.7.

This presents an interesting debate for ergonomics: Are the methods really this mutually exclusive?Presumably, methods that have dual roles (i.e., both analytical and evaluative, such as task analysis forerror identication) must satisfy both criteria. It is possible for a method to satisfy three types of validity:construct (i.e., theoretical validity), content (i.e., face validity), and predictive (i.e., criterion-referencedempirical validity). The three types of validity represent three different stages in the design, development,and application of the methodology, as illustrated in Figure 1.1. There is also the question of reliability,and a method should be demonstrably stable over time and between people. Any differences in analysesshould be due entirely to differences in the aspect of the world being assessed rather than differences inthe assessors.

Theoretical and criterion-referenced empirical validation should be an essential part of the methoddevelopment and reporting process. This in turn should inform the method selection process. Stantonand Young (1999) have recommended a structured approach for selecting methods for ergonomicanalysis, design, and evaluations. This has been adapted for more generic method selection and ispresented in Figure 1.2.

As shown in Figure 1.1, method selection is a closed-loop process with three feedback loops. The rstfeedback loop validates the selection of the methods against the selection criteria. The second feedbackloop validates the methods against the adequacy of the ergonomic intervention. The third feedback loopvalidates the initial criteria against the adequacy of the intervention. There could be errors in thedevelopment of the initial criteria, the selection of the methods, and the appropriateness of the inter-vention. Each should be checked. The main stages in the process are identied as: determine criteria(where the criteria for assessment are identied), compare methods against criteria (where the pool ofmethods are compared for their suitability), application of methods (where the methods are applied),implementation of ergonomics intervention (where an ergonomics program is chosen and applied), andevaluation of the effectiveness of the intervention (where the assessment of change brought about by theintervention is assessed).

TABLE 1.7 Annett's Dichotomy of Ergonomics Methods

Analytic Evaluative

Primary purpose Understand a system Measure a parameterExamples Task analysis, training needs analysis, etc. Measures of workload, usability, comfort,

fatigue, etc.Construct validity Based on an acceptable model of the system and

how it performsConstruct is consistent with theory and

other measures of parameterPredictive validity Provides answers to questions, e.g., structure of

tasksPredicts performance

Reliability Data collection conforms to an underlying model Results from independent samples agree

Source: Adapted from Annett, J. (2002), Theor. Issues Ergonomics Sci., 3, 229232. With permission.




The ultimate criteria determining the usefulness of ergonomics methods will be whether or not theyhelp in analyzing tasks, designing work, predicting performance, collecting data on human performanceand interaction with artifacts and the environment in which this interaction takes place. This requiresthat the twin issues of theoretical validity and predictive validity be addressed when developing andtesting old and new methods. The approach taken in this handbook provides a benchmark on reportingon human factors and ergonomics methods. The information provided here is what all developers shouldask of their own methods and, at the very least, all users of methods should demand of the developers.

References

Annett, J. (2002), A note on the validity and reliability of ergonomics methods, Theor. Issues ErgonomicsSci., 3, 229232.

Annett, J. and Stanton, N.A. (2000), Task Analysis, Taylor & Francis, London.

FIGURE 1.1 Validation of methods. (Adapted from Diaper, D. and Stanton, N.A. [2004], The Handbook of TaskAnalysis for Human-Computer Interaction, Lawrence Erlbaum Associates, Mahwah, NJ. With permission.)

FIGURE 1.2 Validating the methods selection ergonomics intervention process. (Adapted from Stanton, N.A. andYoung, M.S. [1999], A Guide to Methodology in Ergonomics, Taylor & Francis, London. With permission.)

Theory or modelof performance

Methodologyfor prediction

Prediction ofperformance

ActualperformanceValidation of

predictionValidation ofmethod

Validation oftheory

Constructvalidity

Contentvalidity

Predictivevalidity

Develop criteria for ergonomic analysis

Assess pool ofmethods against criteria

Decide uponergonomicsintervention

Select and apply methods:Analyse output

Assessment of theeffectiveness of theintervention

Validateselectionprocess

Validatecriteriadevelopment

Validateassessmentprocess




Baber, C. and Mirza, M.G. (1988), Ergonomics and the evaluation of consumer products: surveys ofevaluation practices, in Human Factors in Consumer Product Design, Stanton, N.A., Ed., Taylor &Francis, London.

Corlett, E.N. and Clarke, T.S. (1995), The Ergonomics of Workspaces and Machines, 2nd ed., Taylor &Francis, London.

Dempsey, P.G., Wolgalter, M.S., and Hancock, P.A. (2000), Whats in a name? Using terms from denitionsto examine the fundamental foundation of human factors and ergonomics science, Theor. IssuesErgonomics Sci., 1, 310.

Diaper, D. (1989), Task Analysis in Human Computer Interaction, Ellis Horwood, Chichester, U.K.Diaper, D. and Stanton, N.A. (2004), The Handbook of Task Analysis for Human-Computer Interaction,

Lawrence Erlbaum Associates, Mahwah, NJ.Diaper, D. and Stanton, N.A. (2004), Wishing on a star: the future of task analysis, in The Handbook of

Task Analysis for Human-Computer Interaction, Diaper, D. and Stanton, N.A., Eds., LawrenceErlbaum Associates, Mahwah, NJ, pp. 603619.

Grandjean, E. (1980), Fitting the Task to the Man, Taylor & Francis, London.Hancock, P.A. (1997), Essays on the Future of Human-Machine Systems, Banta, Minneapolis, MN.Hancock, P.A. and Diaz, D.D. (2002), Ergonomics as a foundation for a science of purpose, Theor. Issues

Ergonomics Sci., 3 (2), 115123.Helender, M.G., Landauer, T.K., and Prabhu, P.V. (1997), Handbook of Human-Computer Interaction,

2nd ed., Elsevier, Amsterdam.Jacko, J.A. and Sears, A. (2003), The Human-Computer Interaction Handbook, Lawrence Erlbaum Asso-

ciates, Mahwah, NJ.Jordan, P.W., Thomas, B., Weerdmeester, B.A., and McClelland, I.L. (1996), Usability Evaluation in

Industry, Taylor & Francis, London.Karwowski, W. and Marras, W.S. (1998), The Occupational Ergonomics Handbook, CRC Press, Boca Raton,

FL.Karwowski, W. (2001), International Encyclopedia of Ergonomics and Human Factors, Vols. IIII, Taylor

& Francis, London.Kirwan, B. (1994), A Guide to Practical Human Reliability Assessment, Taylor & Francis, London.Kirwan, B. and Ainsworth, L. (1992), A Guide to Task Analysis, Taylor & Francis, London.Meister, D. (1989), Conceptual Aspects of Human Factors, Johns Hopkins University Press, Baltimore, MD.Murrell, K.F.H. (1965), Human Performance in Industry, Reinhold Publishing, New York.Salvendy, G. (1997), Handbook of Human Factors and Ergonomics, 2nd ed., Wiley, New York.Sanders, M.S. and McCormick, E.J. (1993), Human Factors Engineering and Design, McGraw-Hill, New

York.Schraagen, J.M., Chipman, S., and Shalin, V. (1999), Cognitive Task Analysis, Lawrence Erlbaum Associ-

ates, Mahwah, NJ.Seamster, T.L., Redding, R.E., and Kaempf, G.L. (1997), Applied Cognitive Task Analysis in Aviation,

Avebury, Aldershot, U.K.Shepherd, A. (2001), Hierarchical Task Analysis, Taylor & Francis, London.Stanton, N.A. (1998), Human Factors in Consumer Product Design, Taylor & Francis, London.Stanton, N.A. and Young, M. (1998), Is utility in the mind of the beholder? A review of ergonomics

methods, Appl. Ergonomics, 29, 4154.Stanton, N.A. and Annett, J. (2000), Future directions for task analysis, in Task Analysis, Annett, J. and

Stanton, N.A., Eds., Taylor & Francis, London, pp. 229234.Stanton, N.A. and Young, M.S. (1999), A Guide to Methodology in Ergonomics, Taylor & Francis, London.Wilson, J.R. (1995), A framework and context for ergonomics methodology, in Evaluation of Human

Work, 2nd ed., Wilson, J.R. and Corlett, E.N., Eds., Taylor & Francis, London, pp. 139.Wilson, J.R. and Corlett, E.N. (1995), Evaluation of Human Work, 2nd ed., Taylor & Francis, London.



Physical Methods



2-1

2Physical Methods

References ..................................................................................... 2-6

The use of physical methods to assess how work is being performed is crucial to the work of manyergonomists. The physical methods included in this section can be used to obtain essential surveillancedata for the management of injury risks in the workforce. It is generally accepted that many musculosk-eletal injuries begin with the worker experiencing discomfort. If ignored, the risk factors responsible forthe discomfort eventually will lead to an increase in the severity of symptoms, and what began as milddiscomfort will gradually become more intense and will be experienced as aches and pains. If leftunchecked, the aches and pains that signal some cumulative trauma eventually may result in an actualmusculoskeletal injury, such as tendonitis, tenosynovitis, or serious nerve-compression injury like carpaltunnel syndrome. Sensations of discomfort are the bodys early warning signs that some attribute of theworkers job should be changed. Discomfort will also adversely affect work performance, either bydecreasing the quantity of work, decreasing the quality of work through increased error rates, or both.Reducing the levels of discomfort actually decreases the risk of an injury occurring. Consequently, changesin levels of discomfort can also be used to gauge the success of the design of an ergonomic product orthe implementation of an ergonomic program intervention.

Three methods are presented (Chapters 3 through 5) that can be used to assess levels of musculoskeletaldiscomfort among workers. These methods all use self-report surveys to quantify discomfort, becausediscomfort cannot be directly observed or objectively measured. The methods in this section are repre-sentative of the range of methods available to the ergonomist. The section does not present a compre-hensive set of all available methods for assessing discomfort. Other methods are available, and several ofthese are referenced in the chapters included in this section. The three chosen methods presented hereare PLIBEL, the U.S. National Institute of Occupational Safety and Health (NIOSH) discomfort surveys,and the Dutch Musculoskeletal Survey.

The PLIBEL method is one of the earliest methods developed to gauge a workers degree of muscu-loskeletal discomfort. It comprises a checklist of items derived from a comprehensive review of theergonomics literature. It allows workers to systematically assess workplace ergonomic hazards associatedwith ve body regions by completing a simple checklist. An assessment can be made for a task or severaltasks or for a complete job. PLIBEL results can serve as the basis for discussions on improvements to jobdesign. PLIBEL is available in several languages.

The NIOSH discomfort questionnaires have been extensively used in U.S. studies of ergonomic hazards.This self-report method allows the ergonomist to easily assess measures of musculoskeletal discomfortin numerous body regions, such as the intensity, frequency, and duration of discomfort. This chapteralso gives a comprehensive list of NIOSH research reports.

The Dutch Musculoskeletal Survey represents one of the most comprehensive and thoroughly validatedsurvey measures of musculoskeletal discomfort. It exists in short and long forms, depending on the intentof its use. It comprises a collection of scales that deal with a broad range of workplace ergonomic hazards,and thus the ergonomist can selectively choose the relevant scales. Analytical software is also availablefor this survey, though only in Dutch at present.

Alan HedgeCornell University




Other survey questionnaires are also available to researchers, such as the Cornell MusculoskeletalDiscomfort Survey (Hedge et al., 1999); the Standardized Nordic Questionnaire (SNQ), which focuseson general body, low back, and neck/shoulder complaints (Kuorinka et al., 1987); and a more recentrevision of this (Dickinson et al., 1992) called the Nordic Musculoskeletal Questionnaire (NMQ). Theseinstruments can be self-administered or interview administered.

Although self-reports of discomfort provide valuable information to the ergonomist, they are intrusiveand they do require some effort on the part of the worker to answer the various questions, and this maybe disrupting to work activities. There is considerable value in using unobtrusive methods to gauge injuryrisks. Consequently, several methods have been developed to systematically assess a workers posturewhile performing work. Posture is an observable reection of musculoskeletal activity, and these methodsall allow the ergonomist to assess risks by systematic observation alone. This means that ergonomicanalyses can be performed on visual recordings of workplaces, such as videotapes or photographs. It isassumed that every body segment moves through a range of motion, termed the neutral zone, withinwhich the anatomical stresses and strains are insufcient to initiate an injury process. However, thefurther the worker makes excursions away from this neutral zone, the greater the injury risk, especiallywhen such excursions are frequently repeated and/or sustained for extended periods. These posturalobservation methods also offer the advantage that they allow high-risk postures to be readily identiedfor corrective action, often even before the worker has been exposed for a sufcient time to developsignicant musculoskeletal discomfort. Thus, when correctly used, posture targeting methods provideeven earlier risk detection capabilities than do discomfort surveys.

Four methods (Chapters 6 through 9) are presented that provide the ergonomist with an excellentarsenal of postural evaluation tools. The Quick Exposure Checklist has a high level of usability andsensitivity, and it allows for quick assessment of the exposure to risks for work-related musculoskeletaldisorders. This method has the advantage that it can be used to analyze interactions between variousworkplace risks, even by relatively inexperienced raters. The RULA and REBA posture-targeting methodsare probably the most well-known methods for rapid assessment of risks. The RULA method is wellsuited to analyzing sedentary work, such as computer work. The REBA method is ideal for rapidassessment of standing work. Both of these methods have been extensively used in ergonomic researchstudies and also in evaluating the impact of workplace design changes on body posture. The Strain Indexis a more comprehensive method that specically focuses on the risks of developing distal upper extremitymusculoskeletal disorders, i.e., injuries of the elbow, forearm, wrist, and hand. All of these methods takelittle time to administer and can be used in a wide variety of work situations. The methods can be usedto assess overall postural risks and/or those to specic body segments.

Other similar posture-targeting methods, such as the Ovako Working Posture Analysis System(OWPAS) (Karhu et al., 1977) and the Portable Ergonomics Observation (PEO) method (Fransson-Hallet al., 1995), have not been included but can also be used. The OWPAS method involves direct observationand sampling of tasks using a whole-body posture-coding system to estimate injury risks. The PEOmethod records hand, neck, trunk, and knee postures and also evaluates manual handling activities, suchas lifting. Real-time observations are directly entered into a computer. Ergonomists can use posture-targeting methods to measure the success of any ergonomic design changes to equipment or to the layoutof a workplace, and the ability to quantify changes in likely injury risk can be a valuable aid to managementdecision making. With the advent of handheld personal digital assistants (PDAs), the ergonomist caneasily carry an extensive ergonomics toolkit into any workplace and generate almost instant analyses andreports, as is shown in Chapter 10, which discusses the use of PDAs.

The measurement of work effort and fatigue was one of the earliest challenges that ergonomists faced,and this challenge remains today. Although the performance of work in more-deviated postures invariablyrequires more muscular effort, which in turn may accelerate muscular fatigue, none of the methods usedto assess discomfort or posture actually yields information on the degree of work effort or on the level



Physical Methods 2-3

of accumulated fatigue that could amplify an injury risk. Two methods are included that quantify effortand fatigue. The Borg Ratings of Perceived Exertion scale (Chapter 11) provides a physiologically validatedmethod for quantifying how much effort is involved in performing physical work. The Muscle FatigueAssessment method (Chapter 12) characterizes discomfort and identies the ways that workers changetheir behavior in an attempt to cope with accumulated fatigue. Both methods are invaluable to thesuccessful design of physical jobs so that neither the quantity nor quality of work performance will sufferover the course of a work shift, and so that the worker will not experience undue physical demands orfatigue that could increase the risks of an injury or accident.

Evaluations of discomfort, work posture, and effort provide valuable insights into possible injury risksin the workplace. However, such approaches do not necessarily help to predict the risks of potentiallyacute injuries, such as back injuries, and they do not set safe limits on work or predict how changes ina job will impact the level of safety. Back injuries account for up to 50% of musculoskeletal injuries inthe U.S., costing the U.S. economy up to $60 billion each year (NAS, 2002), and ergonomic research hasbeen undertaken to set safe limits for lifting work. Two methods for assessing back injury risks arepresented here. Using a psychophysical approach to assessing strength, Snook tables (Chapter 13) set safeweight limits for men and women who perform lifting, pushing, and pulling tasks at work. These givethe ergonomist a quick method for assessing the injury potential of a specic work task that involvesthese actions. Mital tables are a similar tabular method for determining lifting limits (Mital, 1984), andrevised tables were introduced in 1989 to also deal with asymmetrical lifting tasks and conned liftingsituations (Mital, 1989; Mital, 1992). However, Snook tables are presented here because they also set themaximum acceptable weights for lifting and lowering, and set the maximum forces for pushing, pulling,and carrying tasks.

A predictive method for determining back injury risks was pioneered by the NIOSH in 1981 and hasundergone substantial revision and enhancement since then, with a revised equation being introducedin 1991. The NIOSH lifting equation has not been included because it is widely used and is a well-knownmethod (see http://www.cdc.gov/niosh/94-110.html). Also, the lifting equation method does not accountfor motion at the time of lifting, and it does not use any measurement of actual spinal loading. The morerecent Lumbar Motion Monitor method described in Chapter 14 was developed to overcome theselimitations of the NIOSH lifting equation by providing a more direct assessment of the dynamic com-ponents of low back disorder risks at work.

The nal two methods that are described, the OCRA and MAPO methods (Chapters 15 and 16), arethe most comprehensive, yet they are also somewhat complex and the most time consuming. The OCRAindex is a detailed analytical and reliable method that can be predictive of upper-extremity injury risksin exposed worker populations. The OCRA index can also be used as the basis for identifying opportu-nities for task and/or workstation redesign, and as a means of evaluating the success of any interventions.The MAPO method has been specically developed to analyze health-care workplaces, especially thoseplaces where workers are involved in the care and handling of disabled patients, paralyzed patients, andwheelchair-bound patients. Nursing work that involves patient handling poses the greatest risks fordeveloping a lower-back injury, and without ergonomic attention, this situation may worsen as thenursing workforce ages and as the patient population gets heavier. Unlike the majority of the otherphysical methods, the MAPO method also incorporates an assessment of the environment in which thework is being performed.

The range and scope of the methods described in this section provide the reader with the tools toundertake a range of studies, including epidemiological ergonomic research, evaluations of ergonomicprograms and design interventions, surveillance of workplace ergonomic hazards, and the detection andquantication of exposures to adverse workplace physical ergonomic stressors. Armed with this batteryof tools, the ergonomist will be well positioned to systematically tackle a wide range of workplace issuesand to implement effective solutions to the problems that are uncovered.




References

Dickinson, C.E., Campion, K., Foster, A.F., Newman, S.J., O'Rourke, A.M.T., and Thomas, P.G. (1992),Questionnaire development: an examination of the Nordic Musculoskeletal Questionnaire, Appl.Ergonomics, 23, 197201.

Fransson-Hall, C., Gloria, R., Kilbom, A., Winkel, J., Larlqvist, L., and Wiktorin, C. (1995), A portableergonomic observation method (PEO) for computerized online recording of postures and manualhandling, Appl. Ergonomics, 26, 93100.

Hedge, A., Morimoto, S., and McCrobie, D. (1999), Effects of keyboard tray geometry on upper bodyposture and comfort, Ergonomics, 42, 13331349; see also http://ergo.human.cornell.edu/ahm-squest.html.

Karhu, O., Kansi, P., and Kuorinka, I. (1977), Correcting working postures in industry: a practical methodfor analysis, Appl. Ergonomics, 8, 199201.

Kuorinka, I., Jonsson, B., Kilbom, A., Vinterberg, H., Biering-Sorensen, F., Andersson, G., and Jorgensen,K. (1987), Standardised Nordic questionnaires for the analysis of musculoskeletal symptoms, Appl.Ergonomics, 18, 907916.

Mital, A. (1984), Comprehensive maximum acceptable weight of lift database for regular 8-hr workshifts,Ergonomics, 27, 11271138.

Mital, A. (1989), Consideration of load asymmetry, placement restrictions, and type of lifting in a designdatabase for industrial workers, J. Safety Res., 20, 93101.

Mital, A. (1992), Psychophysical capacity of industrial workers for lifting symmetrical and asymmetricalloads symmetrically and asymmetrically for 8 h work shifts, Ergonomics, 35, 745754.

National Academy of Sciences (NAS) (2001), Musculoskeletal disorders and the workplace: low back andupper extremities, National Academy Press, Washington, D.C.



3-1

3PLIBEL The Method

Assigned forIdentification of

Ergonomic Hazards

3.1 Background and Applications .......................................... 3-13.2 Procedure ........................................................................... 3-43.3 Advantages ........................................................................ 3-53.4 Disadvantages ................................................................... 3-53.5 Example.............................................................................. 3-53.6 Related Methods................................................................ 3-53.7 Standards and Regulations ............................................... 3-63.8 Approximate Training and Application Time................. 3-63.9 Reliability and Validity...................................................... 3-63.10 Tools Needed ..................................................................... 3-7References ..................................................................................... 3-7

3.1 Background and Applications

The Swedish Work Environment Act stipulates that the employer shall investigate occupational injuries,draw up action plans, and organize and evaluate job modications. Hence it is also of interest for thegovernments Labour Inspectorate to study conditions and improvements in the workplace.

The method for the identication of musculoskeletal stress factors which may have injurious effects(PLIBEL) was designed to meet such needs (Figure 3.1). PLIBEL has been used in several studies, inpractical on-site ergonomic work, and as an educational tool. It has been presented in various parts ofthe world and translated into several languages (Kemmlert, 1995, 1996a, 1996b, 1997).

PLIBEL is a simple checklist screening tool intended to highlight musculoskeletal risks in connectionwith workplace investigations. Time aspects as well as environmental and organizational considerationsalso have to be considered as modifying factors.

The checklist was designed so that items ordinarily checked in a workplace assessment of ergonomichazards would be listed and linked to ve body regions (Figure 3.1). Only specic work characteristics,dened and documented as ergonomic hazards in scientic papers or textbooks, are listed (Figure 3.2and Figure 3.3). Whenever a question is irrelevant to a certain body region, and/or if documentation hasnot been found in the literature, it is represented by a gray eld in the checklist and need not be answered.

The list was made in 1986, and new references have since then been read continuously and the listupdated. Mostly, these only add knowledge to the primary list, which accordingly has not been changed.

Kristina KemmlertNational Institute for Working Life



3-2H

and

book

of Hu

man

Factors and

Ergon

omics M

ethod

s

FIGURE 3.1 The PLIBEL form.

Method of application.

* Find the injured body region.* Follow white fields to the right.

* Do the work tasks contain

any of the factors described?

* If so, tick where appropriate.

Also take these factors into consideration:

a) the possibility to take breaks and pausesb) the possibility to choose order and type of work tasks or pace of workc) if the job is performed under time demands or psychological stressd) if the work can have unusual or unexpected situationse) presence of cold, heat, draught, noice, or

troublesome visual conditionsf) presence of jerks, shakes, or vibrations

Kemmlert, K. and Kilbom, A. (1986) National Board of Occupational Safety and Health,Research Department, Work Physiology Unit, 17184 Solna, Sweden

7. Is fatiguing foot-pedal work performed?8. Is fatiguing leg work performed, e.g,:

a) repeated stepping up on stool, step, etc.?b) repeated jumps, prolonged squatting, or kneeling?c) one leg being used more often in supporting the body?

1. Is the walking surface uneven, sloping, slippery, or nonresilient?

6. (If the work is performed while standing) Is there no possibility to sit and rest?5. Is the working chair poorly designed or incorrectly adjusted?4. Is the working height incorrectly adjusted?3. Are tools and equipment unsuitably designed for the worker or the task?2. Is the space too limited for work movements or work materials?

9. Is repeated or sustained work performed when the back is:a) mildly flexed forward?b) severely flexed forward?c) bent sideways or mildly twisted?d) severely twisted?

10. Is repeated or sustained work performed when the neck is:a) flexed forward?b) bent sideways or mildly twisted?

c) severely twisted?d) extended backward?

11. Are loads lifted manually? Notice factors of importance as:a) periods of repetitive lifting e) handling beyond forearm lengthb) weight of load f) handling below knee heightc) awkward grasping of load g) handling above shoulder heightd) awkward location of load at onset or end of lifting

12. Is repeated, sustained, or uncomfortable carrying, pushing, or pulling of loads performed?13. Is sustained work performed when one arm reaches forward or to the side without support?14. Is there repetition of:

a) similar work movements?b) similar work movements beyond comfortable reaching distance?

15. Is repeated or sustained manual work performed? Notice factors of importance as:a) weight of working materials or toolsb) awkward grasping of working materials or tools

16. Are there high demands on visual capacity?17. Is repeated work, with forearm and hand, performed with:

a) twisting movements? c) uncomfortable hand positions?b) forceful movements? d) switches or keyboards?

2.3.

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elbows, forearmshands

feet knees and hips low back

TF1539_book.fm

Page 2 Wednesday, July 28, 2004 10:36 A

M


PLIBEL The Method Assigned for Identication of Ergonomic Hazards 3-3

FIGURE 3.2 Documented background for PLIBEL. References, as numbered in the footnote, are given for each riskfactor in relation to body regions, as in the PLIBEL form. Note, however, that in this presentation the distributionis by four body regions. Hips, knees, and feet are combined in the table.

Item12

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11f11g1213

Neck/shoulders,upper part of back

Original papers Review papers and text books

1 Aaras 1987 21 Kvarnstrm 1983 42 Bongers et al. 19932 Anderson 1984 22 Laville 1968 43 Chaffin 19733 Bhatnager et al. 1985 23 Luopajrvi et al. 1979 44 Chaffin and Andersson 19844 Bjelle et al. 1981 24 Magnusson 1991 45 Enander 19845

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