Tài liệu Ergonomics – A Systems Approach potx

ERGONOMICS   ASYSTEMSAPPROACH EditedbyIsabelL.Nunes ERGONOMICS– ASYSTEMSAPPROACH  EditedbyIsabelL.Nunes            Ergonomics – A Systems Approach Edited by Isabel L. Nunes Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2012 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. As for readers, this license allows users to download, copy and build upon published chapters even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Martina Blecic Technical Editor Teodora Smiljanic Cover Designer InTech Design Team First published April, 2012 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechopen.com Ergonomics – A Systems Approach, Edited by Isabel L. Nunes p. cm. ISBN 978-953-51-0601-2    Contents  Preface IX Chapter 1 Work-Related Musculoskeletal Disorders Assessment and Prevention 1 Isabel L. Nunes and Pamela McCauley Bush Chapter 2 Work-Related Musculoskeletal Discomfort in the Shoulder due to Computer Use 31 Orhan Korhan Chapter 3 Ergonomic Impact of Spinal Loading and Recovery Positions on Intervertebral Disc Health: Strategies for Prevention and Management of Low Back Pain 51 S. Christopher Owens, Dale A. Gerke and Jean-Michel Brismée Chapter 4 A Comparison of Software Tools for Occupational Biomechanics and Ergonomic Research 65 Pamela McCauley Bush, Susan Gaines, Fatina Gammoh and Shanon Wooden Chapter 5 Measurement Instruments for Ergonomics Surveys – Methodological Guidelines 119 Marina Zambon Orpinelli Coluci Chapter 6 Biomechanical Assessment of Lower Limbs Using Support Moment Measure at Walking Worker Assembly Lines 131 Atiya Al-Zuheri, Lee Luong and Ke Xing Chapter 7 Usability of Interfaces 155 Mário Simões-Marques and Isabel L. Nunes Chapter 8 User Experience Design: Beyond User Interface Design and Usability 171 Wei Xu VI Contents Chapter 9 Higher Efficiency in Operations Can Be Achieved with More Focus on the Operator 193 Per Lundmark Chapter 10 Critical Thinking Skills for Intelligence Analysis 209 Douglas H. Harris and V. Alan Spiker    Preface  Ergonomics, alsoknownasHuman Factors,isarecentscientificdiscipline,curiously with a well‐defined and official date and place of birth, July 12, 1949, in England. HoweverthetermErgonomics,wasproposedin1857,by thePolishphilosopherand naturalistWojciechJastrzebowskiandfellintooblivionfornearly acentury.Theword Ergonomics results from joining the Greek words ergon meaningʺworkʺ and nomos meaningʺnatural lawsʺ, and conveys the concern of understanding the relationships betweenhumansandtheirworkenvironment. Ergonomics in spite of its short existence, gathers a broad body of knowledge from different disciplines in  order to fit the workplace conditions and job demands to the capabilities of workers. Its main goal is to ensure humans well‐being, health, and safetywhilemaximizingtheperformanceofproductionsystems.Productionsystems, however, are a complex combination of physical, organisational and psychosocial dimensions. Therefore Ergonomics offers principles and methods to analyse and improve this multitude of interactions. Despite production systems being the main focusofErgonomics,itsinterventionextendsbeyondworksystems,tootheraspectsof ourdailylives,likeproductdesign,leisureorsport. This book isthe resultof an InTech initiativetobring together reputable  researchers fromdifferentcountriesthatcouldprovideaninterestingandup‐to‐dateoverviewof different Ergonomic research applications, practices and methodologies. The 10 chapterspresenttheresearchworkof 19authorsfrom 6differentcountries,andthey cover the following themes: work related musculoskeletal disorders; methods in Ergonomics;usability anduser‐experiencedesign;efficiencyinoperations,andcritical thinkingskills.Abriefoutlineofthevolumeispresentedhereafter. Chapter1offersanoverviewonwork‐relatedmusculoskeletaldisorders(WMSD).The recognition that the wor k may adversely affect health is not new, since musculoskeletal disorders have been diagnosed for many  years in the medical field. WMSDarerelatedwithrepetitiveanddemandingworkingconditionsandcontinueto representoneofthebiggestproblems inindustrializedcountries.WMSDarea group of inflammatory and degenerative diseases of the locomotion system, which result fromoccupationalriskfactorssuchasrepetition,forceorawkwardpostureaswellas individual and psychosocial risk factors. This chapter presents WMSD causes, X Preface pathophysiological mechanisms, characterization of the principal disorders and proceduresforworkplaceanalysisanddesign. Chapter 2 presents the risk factors that contribute to musculoskeletal disorders in shoulders resulting from intensive us e of computers. The ri sk factors of musculoskeletal disorders were revealed by assessing and analyzing workplace ergonomics, worker attitudes and experiences  on the use of the computer keyboard and mouse. This was followed by an experimental data collection of muscle load, muscleforceandmuscularfatiguefromtheshoulderbySurfaceelectromyographyto validateandverifytheproposedmathematicalmodel. Chapter3recognisesthatthemanagementoflowbackpain,particularly workrelated injuries,isverycontroversialandthatmanydifferenttreatmentapproacheshavebeen tried, ranging from osteopathic manipulations to work hardening programs. This chapter addresses low back pain reviewing the anatomical, biomechanical, and physiological mechanisms that contribute to the health of the lumbar spine with particularemphasisontheintervertebral disc(IVD);consideringthemechanismsthat maycausepainanddysfunctioninthelumbarspine;andpresentingspecificstrategies for prevention and management of work related low back pain based on the biomechanicalandphysiologicalresponseofthelumbarIVD. Chapter 4 is devoted to the comparison of software tools for occupational biomechanicsandergonomicresearch.Itprovidesasurveyonselectedbiomechanical software tools and gives a detailed analysis and a comparison of two specialized packages, 3DSSPP and JACK as well as examples of applications where one or the othermaybebettersuited. Chapter5presentsadescription of methodologicalguidelinesusedtoprepareanew questionnaireortoadaptanexistingone.Ergonomicsurveysareveryimportanttools to evaluate and identify problems in workplaces (such as industries, hospitals, and laboratories),sincestrategiestotackletheergonomicissuescanbederivedfromtheir results.Therefore,thesurveysshould becarefullypreparedtoobtaininformationina clear and reliable way. Usually, ergonomic surveys are based on measurement instruments (questionnaires) that are applied to workers on the workplace to collect thenecessaryinformation. Chapter 6 discusses the need for dynamic, flexible and reconfigurable assembly systems, which are able to respond  adequately to changes in the characteristics and demandsofthemarket.ThechapterpresentstheWalkingWorkerAssemblyLine,in which each worker utilizes various skills and functions by travelling along the manufacturing line to carry out all the required tasks. The  authors argue that this flexible manpower line (or flexible assembly line) approach is one of the promising techniques for configuring effective and productive assembly systems, responding welltothechallengesofthemanufacturingindustry. Preface XI Chapter 7 is dedicated to usability. In recent years the knowledge media support migrated from “pen and paper” to computer‐based Information Systems. This evolutionintroducedsometechnological,organizational,andmethodologicalchanges affectingthedemand,workloadandstressovertheworkers,manytimesinanegative way. Due to this fact  usability assumed an increasing importance. This chapter presentsanoverviewofthegeneralprinciplestoobservewhena user‐centreddesign isadopted,providesasummaryofmethodsandtoolsthatareavailabletosupportthe design and evaluation of products with good usability, and offers examples of guidelinesand goodpracticesthatcanbeadopted. Chapter 8 discusses major challenges faced by current user‐centred design practices, proposesauserexperiencedesign(UXD)frameworktoaddressthesechallenges,and analyses three case studies to illustrate the UXD approach and formalize the UXD processes. Chapter 9 discusses how human operators are  an integral part of automated control systemsandusingasystematic designapproach presentsanewcontrol roomthatis operator‐focused, in order tocreatea safer and securerenvironment, contributingto efficiencyinoperations. Chapter 10 is devoted to critical thinking skills for intelligence analysis, focusing on that aspect of ergonomics research that seeks to understand how people engage in cognitiveworkandhowtodevelopsystemsandtrainingthat bestsupportthatwork. Adefinitionandamodelofcriticalthinkingarepresented. I hope this book will encourage readers, namely academic researchers and company managers interested in Ergonomics and its applications, to pursue the challenge of transformingworkplacesintosaferandhealthierplacestoworkwhileoptimizingthe worksystemperformance. I would like tothankInTechforthe invitationtobe aneditor and toMartina Blecic, Publishing ProcessManager,for organizing thisbook.I would also liketothank the authorsandotherpersonswhohelpedandencouragedmetomakethisbookareality.  IsabelL.Nunes,M.S.,Ph.D. CentreofTechnologiesandSystems, FaculdadedeCiênciaseTecnologia, UniversidadeNovadeLisboa,Caparica, Portugal  [...]... over affected area Same symptoms as tendonitis Pain, numbness, tingling, burning sensations, wasting of muscles at base of thumb, dry palm Pain at the base of thumb Pain, numbness, swelling of the hands Pain Table 4 Work Related Musculoskeletal Disorders, Symptoms and Risk Factors (Canadian Centre for Occupational Health and Safety, 2011) 18 Ergonomics – A Systems Approach 3 Procedure for workplace analysis... the categories (or modules) were compared, analytic Hierarchy Processing (AHP) analysis was conducted to determine the relative significance of each of the modules: task, personal and organizational characteristics The relative significance (priority weights) obtained for the task, personal, and organizational characteristics are listed in Table 11 The task characteristics module received a relative... each other The psychological strain may impact physical strain by increasing the muscle tension, while the physical strain can influence psychological strain Individual characteristics such as physical and psychological tolerance to fatigue and resistance to stress may moderate many of the above relationships Thus: ‘14’ physical capacity may moderate the relationship between the physical work demands... work demands and physical strain; ‘15’ coping mechanisms may moderate the relationship between psychological work demands and physiological strain; ‘16’ capacity and internal tolerances can impact the extent to which physical and psychological strain affect each other; ‘17’ and ‘18’ indicate that the physical and psychological strain can cause changes in physiological responses, which can provide new... to changes in work style, increased muscle tension or psychological stress ‘11’ and ‘12’ show that the physical and psychological demands of work can have a direct impact on the individual characteristics of workers, through mechanisms of adaptation such as improving their physical or psychological capacity; ‘13’ is a reciprocal pathway that shows that the physical and psychological strains can influence... intended for use as a method obtain the likelihood for WMSD risk for a specific individual performing a task at a given organization The research identified three broad categories (modules) for WMSD risk factors as task-related, personal-related and organizational-related classifications Within each of these categories, additional factors were identified The items identified as risk factors for each of the... countries (EU27, Norway, Croatia, the former Yugoslav Republic of Macedonia, Turkey, Albania, Montenegro and Kosovo) concluded that European workers remain exposed to physical hazards, which means that many Europeans’ jobs still involve physical labour For instance, 33% of workers carry heavy loads at least a quarter of their working time, while 23% are exposed to vibrations About half of all workers (46%)... Ergonomics – A Systems Approach Work-Related Musculoskeletal Disorders Assessment and Prevention 13 As referred non-professional activities can also contribute to the development of WMSD, thus we can add to this model a pathway ‘36’ that represent sport or domestic activities The pathway should impact the ‘physical strain’ box 2.3 The most relevant WMSD and risk factors WRMD are classified according to the affected... suggested to be related to increased fatty tissue within the carpal canal or to increased hydrostatic pressure throughout the carpal canal in obese persons compared with slender persons (Werner et al, 1994) Carpal tunnel canal size and wrist size has been suggested as a risk factor for CTS; however, some studies have linked both small and large canal areas to CTS (Bleecker, et al., 1985; Winn & Habes, 1990)... personal characteristics module had a relative weight of 0.258, less than half of the relative weight of the task characteristics module Finally, the organizational characteristics module received the smallest relative weight, 0.105 Ranking Module Relative Weight 1 Task 0.637 2 Personal 0.258 3 Organizational 0.105 Table 11 AHP Results: Module Risk Comparison Determination of Aggregate Risk Level After . Disorder Japan, Sweden Occupational Overuse Syndrome Australia Repetitive Strain Injury Australia, Canada, Netherlands Work-Related Neck and Upper Limb. load, muscleforceandmuscularfatiguefromtheshoulderbySurfaceelectromyographyto validateandverifytheproposedmathematicalmodel. Chapter3recognisesthatthemanagementoflowbackpain,particularly workrelated injuries,isverycontroversialandthatmanydifferenttreatmentapproacheshavebeen tried,