ergonomic evaluation of workers at a cabinet mill and assembly plant

Ergonomic Evaluation of Workers at a Cabinet Mill and Assembly Plant

Bich Dang, MD

Daniel Habes, MSE, CPE

National Institute for Occupational Safety and Health

Jessica Ramsey, MS

Health Hazard Evaluation Report HETA 2007-0038-3057 Yorktowne Cabinets Mifflinburg and Red Lion, Pennsylvania March 2008

DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention

Workplace Safety and Health

https://www.cdc.gov/niosh/hhe/reports

http://www.cdc.gov/niosh/hhe/

http://www.cdc.gov/niosh/hhe/

The employer shall post a copy of this report for a period of 30 calendar days at or near the workplace(s) of affected employees. The employer shall take steps to insure that the posted determinations are not altered, defaced, or covered by other material during such period. [37 FR 23640, November 7, 1972, as amended at 45 FR 2653, January 14, 1980].

Contents

RepoRt Abbreviations........................................................................ ii

Highlights.of.the.NIOSH.Health.Hazard.Evaluation............. iii

Summary............................................................................. iv

Introduction...........................................................................1

Assessment..........................................................................2

Results.and.Discussion........................................................4

Conclusions........................................................................19

Recommendations..............................................................19

References.........................................................................31

ACknowledgments Acknowledgements.and.Availability.of.Report....................33

Health Hazard Evaluation Report 2007-0038-3057 Page �

AbbReviAtions

HHE Healthhazardevaluation

MSD Musculoskeletaldisorder

NIOSH NationalInstituteforOccupationalSafetyandHealth

OSHA OccupationalSafetyandHealthAdministration

RCB Revolvingcabinetbase

RNLE RevisedNIOSHLiftingEquation

WMSD Work-relatedmusculoskeletaldisorder

Page �� Health Hazard Evaluation Report 2007-0038-3057

HigHligHts of tHe

niosH HeAltH

HAzARd evAluAtion

Health (NIOSH) received a

in December 2006.

The National Institute for Occupational Safety and

management request for a health hazard evaluation at Yorktowne Cabinets in Mifflinburg and Red Lion, Pennsylvania. Site visits were performed

NIOSH evaluated potential ergonomic hazards and explored ways to decrease the number of work-related musculoskeletal injuries.

What NIOSH Did

● Weinterviewedworkersabouttheirworkandmedicalhistory, andanyhistoryofwork-relatedmusculoskeletaldisordersto determinethescopeofinjuriesoccurringattheplants.

● WelookedatOccupationalSafetyandHealthAdministration injurylogsandworkers’compensationdata.

● Wewatchedworkersmilling,assembling,andshipping cabinets.

What NIOSH Found

● Wefoundthatworkersusehighforce,awkwardpostures, andrepetitivemotionsthatincreasetheirriskfordeveloping musculoskeletaldisorders.

● Wefoundthatworkerswithwork-relatedachesandpains usuallydonotreportthemuntiltheyaresevere.

What Yorktowne Managers Can Do

● Managersshouldprovideemployeeswithadjustabletablesand adequateworkspacetocompletejobtasks.

● Managersshouldprovideassistdevicessuchasjigs,vices,and carouselstandsthatholdandrotateworkobjectstoreduce awkwardorextremebodypostures.

● Managersshouldselectlightweighttools,properlydesignedfor eachtask,todecreaserequiredforceandimprovewristposture.

● Managersshouldreducevibrationexposurebyproviding toolswithlowvibrationfrequencyandproperlymaintaining thosetools.Managersshouldschedulerestbreaksandrotate employeestoworktasksthatdonotinvolvevibrationexposure.

● Managersshouldcreatearoutinemaintenanceprogramfor toolsandcarts.

● Managersshouldprovidetrainingforworkerssotheycanspot unsafeworkpracticesandrecognizeearlysignsofinjury.

What Yorktowne Employees Can Do

● Employeesshouldpromptlyreportinjuriesorunsafework conditionstomanagement.

● Employeesshouldtakethetimetoworksafelyandliftproperly.

● Employeesshouldbecomeinvolvedwithsafetyandergonomic groups.

Health Hazard Evaluation Report 2007-0038-3057 Page ��

summARy

to a combination of risk Most workers are exposed

factors for developing musculoskeletal disorders. Risk factors include high forces, awkward postures, and repetitive motions. The use of adjustable tables and carts, as well as improved workplace and tool design would reduce physical stresses and the risk of musculoskeletal injury.

OnOctober24,2006,NIOSHreceivedanHHErequestfrom managementatYorktowneCabinets,Inc.toevaluatepotential ergonomichazardsattheMifflinburg,Pennsylvaniamilland theRedLion,Pennsylvaniaassemblyplant.Continuedworkers’ compensationclaimsforMSDsdespiteattemptsbymanagement tocontrolinjuriespromptedtherequest.

OnDecember4–8,2006,NIOSHinvestigatorsconductedsite visits.OnDecember4,2006,NIOSHinvestigatorsheldan openingconferencewithmanagement,employee,andunion representatives.NIOSHergonomistsperformedwalk-through surveysoftheworkareasatbothfacilitiestoobservethetypical jobtasks.TheNIOSHphysicianconductedconfidentialmedical interviewsandreviewedOSHA’sForm300LogofWork-Related InjuriesandIllnessesandworkers’compensationdata.NIOSH investigatorsheldclosingconferencesateachfacilityandprovided preliminaryrecommendationstothosewhoattended.

NIOSHinvestigatorsfoundthatworkersareexposedtoa combinationofriskfactorsforMSDsinvolvingtheupper extremitiesandlowback.Worktasksrequiringhighlyrepetitive motions,extremeandawkwardpostures,andforcefulexertions forupperextremities;andheavylifting,bending,andtwisting forlowbackwereobserved.Workstationandtooldesignsthat placeworkersatriskforMSDsincludelowworkheights,non-adjustableworkstations,heavytools,andexcessvibrationexposure. TheOSHALogreviewindicatedthatmostentrieswereMSDs involvingtheupperextremities.Thirtyofthe33interviewed workersreportedwork-relatedmusculoskeletalpainordiscomfort. Ofthese30injuries,26involvedtheupperextremity.

Recommendationsforreducingtheriskofinjuryarecontainedin thisreport.Theuseofadjustabletablesandcartsandimproved workplaceandtooldesignwouldeliminateorsignificantlyreduce thephysicalstressesassociatedwiththeobservedjobtasks.

Keywords: NAICS 337110 (Wood Kitchen Cabinet and Countertop Manufacturing), repetitive motions, work-related musculoskeletal disorders, ergonomics, bending and reaching.

Page �v Health Hazard Evaluation Report 2007-0038-3057

intRoduCtionOnOctober24,2006,NIOSHreceivedahealthhazardevaluation requestfromtheSafetyandEnvironmentalManageratYorktowne Cabinets,Inc.inMifflinburg,Pennsylvania,toevaluatepotential ergonomichazardsamongcabinetmakers.Therequestwas promptedbycontinuedworkers’compensationclaimsfiledfor MSDsdespiteattemptsbymanagementtodecreasethenumberof injuryoccurrences.

OnDecember4–8,2006,NIOSHinvestigatorsconductedsite visitsatthemillinMifflinburg,Pennsylvania,andtheassembly plantinRedLion,Pennsylvania.TheNIOSHteamconsistedof aphysicianandtwoergonomists.OnDecember4,2006,NIOSH investigatorsheldanopeningconferencewithmanagement, representativesfromthefacilities’ergonomicsteam,andthe PresidentoftheUnitedBrotherhoodofCarpentersLocal2837. NIOSHinvestigatorstouredthemanufacturingareastoobserve specificsorting,machining,sanding,anddoor/framebuilding tasksattheMifflinburgmill;andspecificassembly,partspulling, andmachiningtasksattheRedLionassemblyplant.Also,NIOSH investigatorsconductedconfidentialmedicalinterviewswiththe cabinetworkersatbothlocationsandreviewedOSHALogsand workers’compensationdataforthepast5years.OnDecember8, 2006,NIOSHinvestigatorsheldaclosingconferenceandprovided preliminaryrecommendations.

Process Description YorktowneCabinets,Inc.,ownedbyElkayManufacturing Company,isoneofthenation’slargestproducersofsemi-custom cabinetry,withdistributioneastoftheMississippiRiver.Itconsists ofthreefacilities:adimensionmillinMifflinburg,Pennsylvania andtwoassemblyplants,oneinRedLion,Pennsylvaniaand anotherinDanville,Virginia.

TheprocessbeginsatthemillinMifflinburgwheregreenlumber isdriedandgoesthroughaseriesofdimensioningprocesses. Molderscutvariouswidthsandlengthstofinersizes.Thefinal processattheMifflinburgplantinvolvestheproductionof allframes,doors,anddrawercomponentswithwoodworking machineryinpreparationforshipmenttooneofthetwo Yorktowneassemblyplants.Whencomponentsarriveatthe assemblyplants,theyarefinemilled,assembled,finished,and shippedtocustomers.


intRoduCtion (Continued)

Assessment

NIOSHinvestigatorsfocusedonthedimensionmillin Mifflinburg,PennsylvaniaandtheassemblyplantinRedLion, Pennsylvania.TheMifflinburgmillemploysapproximately230 workersoverthreeshifts,withthethirdshiftprimarilyinvolving maintenancetasks.TheRedLionassemblyplantemploys approximately225workersoverthreeshifts,withthethirdshift primarilyinvolvingthefinishingoperations.Workersatboth plantsarerepresentedbytheUnitedBrotherhoodofCarpenters.

NIOSHinvestigatorsconductedawalk-throughassessmentofthe millandassemblyplanttoobservetheprocessesofmachining andbuildingcabinetcomponentparts,assemblingcabinets,and shippingfinishedcomponents.Digitalvideosandmeasurementsof workstationheightsandreachdistancesweretakentodocument thetasksperformedbytheworkers.

NIOSHinvestigatorsreviewedOSHAForm300LogsofWork-RelatedInjuriesandIllnessesfrom2002–2006andworkers’ compensationdatafrom2002–2006.Inaddition,theNIOSH physicianperformedconfidentialmedicalinterviewswith employeesseriallyselectedfromanemployeerosterforall productiondepartments.Incaseswhereselectedemployeeswere notabletoparticipate,managementselectedemployeesknownto haveaWMSD.

Interviewquestionsconcernedpersonalcharacteristics,medical history,jobduties,andWMSDs.Employeesexperiencingpain ordiscomfortwereaskedwhethertheprobleminterferedwith theirabilitytoperformtheirjob,causedthemtoseeaphysicianor chiropractor,orcausedthemtomissdaysofworkortobeplaced onrestrictedworkduty.Employeeswerealsoaskedtoidentifythe locationoftheirpainordiscomfortonabodymap.

Ergonomic Evaluation Criteria ThetermMSDsrefertoconditionsthatinvolvethenerves, tendons,muscles,andsupportingstructuresofthebody.WMSDs areamajorcomponentofthecostofwork-relatedillnessinthe UnitedStates.Asubstantialbodyofdataexistsprovidingstrong evidenceofanassociationbetweenMSDsandcertainwork-related factors(physical,workorganizational,psychosocial,individual, andsociocultural).ThemultifactorialnatureofMSDsrequiresa discussionofindividualfactorsandhowtheyareassociatedwith

Page � Health Hazard Evaluation Report 2007-0038-3057

Assessment (Continued) WMSDs.Thereisstrongevidencethatworkinggroupswithhigh levelsofstaticcontraction,prolongedstaticloads,orextreme workingposturesinvolvingtheneck/shouldermusclesareat increasedriskforneck/shoulderMSDs[NIOSH1997].There isalsostrongevidencethatjobtasksthatrequireacombination ofriskfactors(highlyrepetitious,forcefulhand/wristexertions) increaseriskforhand/wristtendonitis[NIOSH1997].Lastly, thereisstrongevidencethatlow-backdisordersareassociated withwork-relatedliftingandforcefulmovements[NIOSH1997]. Anumberofpersonalfactorscanalsoinfluencetheresponseto riskfactorsforMSDsincluding:age,gender,smoking,physical activity,strength,andanthropometry.Althoughpersonalfactors mayaffectanindividual’ssusceptibilitytooverexertioninjuries/ disorders,studiesconductedinhigh-riskindustriesshowthatthe riskassociatedwithpersonalfactorsissmallcomparedtothat associatedwithoccupationalexposures[NIOSH1997].

Inallcases,thepreferredmethodforpreventingand controllingWMSDsistodesignjobs,workstations,tools,and otherequipmenttomatchthephysiological,anatomical,and psychologicalcharacteristicsandcapabilitiesoftheworker.Under theseconditions,exposurestotaskfactorsconsideredpotentially hazardouswillbereducedoreliminated.

Thespecificcriteriausedtoevaluatejobswereworkplaceand jobdesigncriteriafoundintheergonomicsliteratureand recommendationsforacceptableliftingasdeterminedbythe RNLE[Waters1994].

Workstationdesignshoulddirectlyrelatetotheanatomical characteristicsoftheworker.Sinceavarietyofworkersmayusea specificworkstation,arangeofworkheightsshouldbeconsidered. Baseduponfemale/male50thand95thpercentileanthropometric data,workstationheightsshouldbewithinarangeof27.6inches tonohigherthan60inches[Kroemer1989].Theseheights correspondtoknuckleandshoulderdimensionsofU.S.civilians, age20to60years.

TheRNLEisatoolforassessingthephysicaldemandsoftwo-handedliftingtasks.Theequationprovidesarecommended weightlimitandliftingindexforaliftingtask,baseduponthe liftingconditions[Waters1994].TheRNLErecommendswhen initiatingaliftthattheverticalheightofthehandsabovethefloor shouldbe30inches(75cm).Aheightof30inchesabovethefloor


Assessment (Continued) isconsidered“knuckleheight”foraworkerofaverageheight.The RNLEalsostatesthatinidealliftingconditions,themaximum recommendedweightlimitis51pounds.Therefore,aworker shouldnotliftanythingover51poundswithoutassistancefrom anotherworker[Waters1994].

Results And disCussion

Mifflinburg, Pennsylvania Dimension Mill

Department 61 – Lumberyard

Workersatthelumberyardreceive,grade,dry,andsortrawlumber. Duringthewalk-throughtourofthisarea,managementstated thatadjustablelifttablesandnewmachinestoeliminatemanual materialhandlingwereexpectedinJanuary2007.Becauseofthese plannedchanges,NIOSHinvestigatorsdidnotevaluatethisarea.

Department 62 – Rough Mill

Lumberiscuttoappropriatelengthsandwidthsintheroughmill. Currently,employeesvisuallyinspectandmanuallymarkthewood withacrayon.Toinspectallfoursidesinatimelymanner,this processrequiresfastflippingofthewoodandresultsinradialand ulnardeviationofthewrist.Themachinereadsthecrayonmark withascannerandcutsatthemarks.Managementstatedthat thisareawouldbereceivingnewmachines.Thenewmachines willeliminatethemanualhandling;anembeddedscannerwill recognizedefectsinthematerialandcutwithouttheneedfor flippingandmarking.

Intherippingarea,aworkerreceivesalargeskidofwoodfrom aforklifttruck.Theworkermanuallyliftseachpiecetoaroller conveyor,linesupthewoodwiththeappropriatestoptomakea specificlengthcut,makesthecut,andslidesthecutpiecedown therollerconveyortoanotherworkerwhostacksthematerialon cartsaccordingtolength.Onthedayweobservedthistask,the initialskidofwoodwasstackedhighenoughtocausetheworker tofullyextendtheshoulder(Photo1).


Results And disCussion (Continued)

scrap yor

shoulder extension

conve

chute

Photo 1. Stack height of wood is high, requiring full shoulder extension.

Aspiecesofwoodareremoved,eventuallythestackheight decreasesandcausestheworkertobendobliquelyatthewaist whenliftingwoodpiecestoplaceontherollerconveyor.

Aspecificjobtaskwhichwebelieveincreasesthelikelihoodof shoulderdiscomfortinvolvestheprocessofdiscardingscrap piecesontothescrapconveyor.Ontherightsideofthesaw,the workerslidesthescrappiecedownachuteanditfallsontoa scrapconveyor.Ifthescrappieceisontheleftsideofthesaw,the workerpicksupthepieceandthrowsitontothescrapconveyor. Thisrepetitivelefthandthrowingmotioncanleadtoshoulder strainamongworkerswhoperformthistask.

Department 63 – Final Machining

Finalmachiningisperformedaftertheroughmillingprocess. Workerscutthewoodtofinallength,runthewoodthrough moldingmachines,andassembledoorblanks.Thesawoperators, machineloaders,andmaterialhandlersdonothaveheight-adjustablecarts(Photo2).Someofthecartsaremodifiedwith palletstoelevatethewoodstackstoamoreappropriateheight.

Moldersplaceseparatorsbetweenthestacksofwoodontheoutput carts.Separatorsarepiecesofscrapwoodthatdividethestacks ofmoldedwoodtopreventdamageandwarping.Theseparators arelocatedonthefloorbehindtheworker(Photo3),causingthe workertowalkbackandforthbetweentheseparatorsandthe outputcartandtotwistandbendbelowkneeheighttopickupthe separators.



Photo 2. Carts without height adjustment.

Photo 3. Separators located on floor behind worker.

Clampingmachinesmakeblanks,whicharegluedpiecesofwood thatarecutdownandsandedtomakeacabinetdoor.Aworker loadspiecesofwoodofvarioussizesontoarollingconveyor.The piecesofwoodpassunderanOptisizerthatmeasuresthesizeof thepieceandpickstheappropriatenumberofpiecesofwoodto makeacertainsizeblank.TheOptisizersendsthosespecificpieces downtheconveyor,overaglueroller,toanotherworkerwhomust


Results And disCussion (Continued) reachforwardtopullthestacksofwoodtogether(Photo4a),pick

themup(Photo4b),andplacethemontheclampingmachine.At theclampingmachine,theworkerreachesforwardagaintoplace thepiecestowardthetop(Photo4c).

4a 4b 4c

Photo 4a. Forward reaching motion to pull stacks of wood together. Photo 4b. Wrist flexion and ulnar deviation when picking up stacks of wood. Photo 4c. Forward reaching motion to load the clamping machine.

Aframeholdsthepieceswhiletheworkerpushesabuttonto tightentheclampthatholdsthepiecesintheframewhiletheglue dries.Afterthepiecesaredry,theworkerplacestheblanksontoa cart.Toreducetheamountofwalking,theworkerusuallystacks twoblanksandcarriesbothtothecart.Eachblankcanweighup to30pounds;whenworkerscarrytwoblanksatatime,theweight isupto60pounds.

Bothoftherollerconveyorshavea“diverterbar”tomergewood piecestogether.However,thecurrentconfigurationofoneofthe diverterbarsisnotpositionedcorrectlyandrequirestheworker toreachforwardtorepositionthewoodpiecesclosertotheedge beforelifting(Photo4a).

Inonesectionwithintheareawhereblanksaremade,anOptisizer andgluerollerarenotusedandaworkermustmanuallydipthe piecesofwoodinglueandplacethemonatableforanother workertoloadtheclampingmachine(Photo5).Whenperforming

4a4a 4b4b 4c4cmanualgluedipping,theworkersuseanawkwardwristposture includingwristflexionandulnardeviation.Also,thereisno pneumaticsystemsotheworkersmanuallytightentheclamp, resultinginhighgripforceandrepetitivemotion.



Photo 5. Wrist flexion and ulnar deviation while dipping wood in glue.

Department 64 – Front Frames

Workersinthisareasandandassemblemachinedpiecesinto cabinetfrontframes.Thetilttablesusedtobuildtheframesare angledsothatworkersmustreachforwardaboveshoulderheight wheninstallingscrewsinthetopcornersoftheframe.

Department 65 – Door Assembly

Inthepartspullarea,workersretrievepiecesfromstorageshelves tobesandedandassembledintofinisheddoors.Severallarger piecesarelocatedatthetopoftheshelves,requiringworkersto climbladderstoretrievematerialsanddescendtheladderwith heavypiecescarriedoverhead.Conversely,smallpiecesarelocated atthebottomoftheshelves,resultinginexcessivebending.

Intheareawherelongpiecesaremitered,workersbalancelong piecesofwoodtoholdtheminthecorrectpositionforthemiter saw.Workersmiteringlongpiecesdonothavearollerstandto holdtheendsandmustusetheirupperextremitytoholdthepiece inplace.

Inthemiterpindoorlinearea,workersusepneumaticstaplers toassemblecabinetdoors.Managementinstructedworkersto holdandflipthedoorwiththeirnon-dominanthandandkeep theirdominantwristneutralwhilestaplingthedoorcomponents together.However,workersmustfullyextendtheirnon-dominant armaboveshoulderleveltoperformthismaneuver,which increasestheriskforshoulderinjuries(Photo6).



Photo 6. Worker flipping door during assembly.

Tominimizeshoulderfatigue,workersholdthedoorsstationary androtatethestaplerwiththeirdominantwristinstead.Although thiswristbendingmotionalleviatesshoulderdiscomfort,it increasestheriskforwristinjuriesintheirdominanthand.

Sanding,includinghandsanding,isperformedbeforethepieces areshippedtotheassemblyplantsforfinishing.Someofthe workersmanuallysandcabinetcomponentswhileothersuse electric-poweredorbitalsanders.Todothejobcorrectly,workers usingorbitalsanderspalm-gripthetopofthesanderandhold palmpressureonthetrigger(Photo7).Workersexposedto continuoustoolvibrationandpalm-gripreportedupperextremity painandnumbness,aswellaslossofgripstrength.

Photo 7. Worker using orbital sander.

Workersperformingmanualsandinghavesetsofhandsanding tools,butreportednotusingthemfortworeasons:thetools’ sandingsurfacesarenotproperlydesignedtofitintointricate


Results And disCussion (Continued) groovesofthewoodand/orthetools’handlesarenotwell

contouredandpushintothepalmofthehand.Workersovercome theseissuesbyusingsmallpiecesofsandpapertosandwithin thegrooves;however,thismotionrequiresapinchgripthatthey reportedcausingpainanddiscomfort.

Neithersetofworkersperformingsandinghaveheight-adjustable worksurfacesorheight-adjustablecarts,andfrequentlybendto pickupincomingpiecesandputdownoutgoingpieces.

Medical Interviews

TheNIOSHphysicianinterviewed19cabinetworkersatthe Mifflinburgmill.Sixof19employeeswereselectedbymanagement; theotherswereseriallyselectedfromanemployeeroster.Among theemployeesinterviewed,theaverageagewas48years(range: 29to62years),andtheaveragetimeemployedatYorktownewas 13years(range:4.5to27.5years).Eighty-ninepercent(17of19) ofemployeesinterviewedreportedsometypeofmusculoskeletal painordiscomfortwithinthelastyearthattheyrelatedtowork. Therewere15reportsofsymptomsinvolvingtheupperextremity (fingers,hand/wrist,elbow/forearm,shoulder),oneneck,oneback, andonelowerextremity.Eightofthe19employeesinterviewed reportedseeingaphysicianorchiropractorwithinthepastyear forwork-relatedmusculoskeletalpainordiscomfort.Threeout ofthe19interviewedemployeeshadbeendiagnosedwithcarpal tunnelsyndromeandthreeadditionalemployeesreportedfinger tinglingandnumbnessand/orlossofgripstrength,allsymptoms whichhavebeenassociatedwithnerveinvolvement.Oneemployee reportedmissingworkwithinthepastyearforwork-related musculoskeletalissues.Anotheremployeetransferredtoadifferent departmentbecauseofwork-relatedmusculoskeletalproblems.

OSHA 300 logs

NIOSHinvestigatorsreviewedOSHALogsandfoundthatmost entrieswereMSDs(notincludingacuteinjuriessuchasfractures, laceration,puncturesorcontusions).From2002through2006, 52%(38of73)oftheOSHA-recordableMSDsattheMifflinburg millinvolvedtheupperextremity.OSHALogsdocumented32 MSDsin2006(18upperextremity,5lowerextremity,4groin,3 back,1neck,1abdomen);33in2005(21upperextremity,7back, 2lowerextremity,2groin,1neck);25in2004(15upperextremity, 3back,5lowerextremity,1groin,1hip);19in2003(9upper extremity,6lowerextremity,3back,1unspecifiedbodypart);and

Page �0 Health Hazard Evaluation Report 2007-0038-3057

Results And disCussion (Continued) 41in2002(22upperextremity,9lowerextremity,8back,1neck,

1pelvis).

Workers Compensation Data

TheMifflinburgmillreported12workers’compensationclaimsfor MSDsin2006,16in2005,8in2004,9in2003,and8in2002.

Red Lion, Pennsylvania Assembly Plant

Mill

Finemillingisperformedonpiecesreceivedfromthedimension millinMifflinburg,Pennsylvania.Inthepartsstoragearea,pieces areshelvedatvariousheights.Oftenlarger,heavierpiecesare storedaboveshoulderlevelandsmaller,lighterpiecesarestored belowkneeleveloftheaverageworker.Thiscurrentstorage methodcausesworkerstoreachoverheadorbendrepeatedly duringtheworkshift.

Theflowlineareacontainsaseriesofmachinesthatcutshelfholes andothernotchesinthecabinetcomponents.Atthebeginning oftheflowline,rawmaterialsaredeliveredbyarollerconveyor. Therollerconveyordoesnottransportmaterialsdirectlytothe firstmachine;thereforeworkersmustmanuallylifteachpiecefrom theconveyorandcarryittothefirstmachine(Photo8).When theworkercannotkeepupwiththepaceoftheincomingraw materials,therawmaterialstravelfartherdowntherollerconveyor linewheretheypileupinasectioncalledtheoverflow.

Photo 8. Worker manually lifting and carrying material to the first machine.



Photo 9. Sheets of cut wood stacked on pallets.

Betweeneachprocessline,workersplacesheetsofcutwoodon pallets(Photo9).Onceanorderiscomplete,workerspushpallets overtherollerconveyortothenextprocess.Therollerconveyoris flatandtheworkerswereobservedtousequiteabitofexertionto pushthepallets.

Neartheendoftheflowline,movementofmaterialfromone processlinetoanotherrequirespushingawheeledcartona floorrailsystem.Thefloorrail’scurrentdesigncreatesresistance betweenthewheelandthefloor,requiringtheworkerstoexert considerableforcewhenpushingthecart.Inanotherareawith awheeledcart/floorrailsystem,anangle-ironrailliftsthewheel abovethefloorandminimizestheresistance(Photo10).

flat rail

angle iron rail

Photo 10. Cart on flat rail design (left); cart wheel on improved angle iron rail system (right).


Results And disCussion Finish(Continued) Inthefinishdepartment,aconveyorsystemmovespiecesthrough painting,wiping,andglazingareas.Atthebeginningofthe process,workersremovepiecesfrompallets/cartsandplacethem onboxesthatsitontheconveyorsystem.Piecesthentravelthrough thedifferentfinishareas(Photo11).

Photo 11. Low conveyor height placing workers at risk for low back pain.

Ineachofthefinishareas,workersmustworkinabentposition toperformthevariousprocessesbecauseofthelowconveyor heightwhichputsthematriskforlowbackpain(theworking heightoftheconveyoris25”).Tocompensateforthelowconveyor height,piecesareplacedon5”boxes.Thedepartmentsupervisor explainedthatvarioussizedboxes(6”,8”,and12”)hadbeenused inthepastinordertoelevatetheworkheightbutthatthelarger pieceswouldnotfitintotheovenwhenplacedonthehigher boxes.However,welearnedthelargerpiecescompriseonly2%– 3%ofthetotalpiecesthatarefinished.

Duringthefinishingprocess,workersremovepiecesfromtheline andplacethemonahighersurfaceforwiping.Thiseliminates bendingduringthewipingprocess,butrequirestheworkerto repeatedlybendtopickupthepartandplaceitbackonthe conveyor.Ragsandothermaterialsarestoredunderneaththework tables,againrequiringbendingatthewaist.Someworkersrotateto differentworkstations,butothersdonot,whichmeanstheystoop andbendforseveralhoursatatime.


Results And disCussion (Continued) Theconveyorsystemtravelsinacircle.Inthesectionwhere

thebeginningandendoftheprocessesmerge,workerstransfer materialsfrompalletstotheconveyor,andviceversa.Boththelow heightoftheconveyorline(25”)andlackofheight-adjustablecarts forthepartscauseworkerstoperformtheirworkbentforward mostoftheworkday.

Thefinishlinerepairareaconsistsoffourorfivetableswhere repairsareperformed.Therepairareaisclosetothefinishline, andworkersreportedodorsfromthefinishingchemicals.Noneof thetablesinthefinishlinerepairareawereheightadjustable,and oneofthetablesdidnothavedirectexhaustventilation.

Assembly

Theendproductisproducedintheassemblyarea.Variousstyles andsizesofcabinetsareproducedaccordingtosemi-custom orders.Theordersaregivenanumberandworkersbuildthe cabinetsinsequentialorderbynumber.Occasionally,large cabinetsareconstructedback-to-back.Workersreportedthat assembling,lifting,andmovinglargecabinetsback-to-backcauses pain,discomfort,andmusclefatigue.

Cabinetcomponentsarebroughttotheworkstationonkitcarts. Thecurrentkitcartwheelsaresmallandcreateresistancewiththe oldwoodenfloor,requiringworkerstousealotofforcetopush andpullthecarts.Managementhasbegunreplacingthesmall wheelswithlargerwheelsthattravelwithlessresistanceacrossthe woodplankfloor.

Theassemblycellsdonothaveanyheight-adjustabletables, exceptforonetableintherepairarea.Workersexplainedthat flippingtheproducttostapleandscrewparts,aswellastwisting andturningthefinalproducttomoveitontotheconveyorline (especiallythelargerpieces)requireawkwardwristposturesand causeupperextremitypainanddiscomfort.Currently,nocarousels or“lazysusan”componentsareavailabletorotatecabinetsand provideworkerseasieraccessfromvariousangles.

Mostcabinetsintheassemblyareahaveamountingfixture thatholdstheproductwhileworkersinstallparts.However,the stationarybasefrontslackadoormountingfixturetoholdthe doorwhileitisbeinginstalled.Thisisafairlynewproduct,anda mountingfixturehasnotbeendevelopedyet.


Results And disCussion (Continued) “Broomer”cabinets,similartofree-standingpantries,aremadeand

boxedforshipmentinthebroomerassemblyarea.Thisareahas severalpneumatichosesonthefloorthatposeatrippinghazard. Otherassemblyareashavecoiledhoses,inwhichmultipletools canplugintooneline;coiledhosesshouldbeutilizedhereto eliminatethehazard(Photo12).

Photo 12. Loose hoses pose a tripping hazard (left); coiled hoses eliminate the trip hazard (right).

Thesizeofthebroomerproductrequirestheworkerstoreach downintothecabinettostaplethecomponenttogether(Photo 13).Noheight-adjustabletableisavailableinthisarea.

Photo 13. Simulation of extreme reach to staple cabinet components (broomer product).


Results And disCussion (Continued) Afterthebroomerproductisassembled,theworkersmakea

customizedboxforshippingbytapingtwosmallerboxestogether. Theworkersthenslidethebroomerproductintothecustomized box.Occasionallytheproductcatchesontotheoverlapwherethe twoboxesjoin,requiringtheworkerstouseexcessivepushandpull forcetoslidetheproductintothebox(Photo14).

box overlap

Photo 14. Overlap of the two boxes where the broomer product gets caught.

AnotherproductwithitsownassemblyareaistheRCB.Engineers atYorktownedesignedspecializedturntableswithcomplementary edgesthatmatchtheRCBcabinetcomponents.Theutilityofthe turntablescouldbeenhancedbydesigningapneumaticclamp structuretosecurelyholdtheRCBpartsinplacewhiletheworker installsthescrews.Thisdesignwouldeliminatethegripforce currentlyrequired.

Fiveparallelconveyorlinesattachtoanelevatedplatformand transporttheboxedRCBcabinetstoashippingarea.Astep betweenthefirsttwoconveyorlinesallowsworkerstoclimbup toordownfromtheplatformtothefloor.Nosimilarstepsexist betweentheremainingconveyorlines,soworkersmusthopoffthe platformtoreachthefloor.

Shipping

Threeactivitiestakeplaceintheshippingdepartment:assembling boxes,placingcabinetsinsidetheboxes,andstagingboxesfor delivery.


Results And disCussion (Continued) Duringboxassembly,workerscutthecardboardboxestosize,

foldthemflatonatable,thencarrythemtonearbyshelvesand storetheminverticalslots.Theseshelvesarelocatedonaplatform severalfeetabovethefloor,whichrequirestheworkertoreach overheadtoplacetheflattenedboxesinthetopslots(Photo15).

Top slots

Photo 15. Top shelf slots require workers to reach overhead.

Placingcabinetsinsideboxestakesplaceontheothersideofthe shelvesandontheplatformwherefinishedcabinetsreadytobe boxedarriveviaaconveyorsystem.Workersretrievestoredboxes fromtheshelves,unfoldthem,andplacethemoverthecabinets. Afterthetopoftheboxissecured,aworkermanuallyflipsthebox overtosecurethebottom.Currently,theydonotuseanautomatic boxcloser,andworkersrotatebetweenstationstoreducefatigue frommanualtilting.

Lastly,workersstagetheboxedcabinetsfordeliverybyorder number.Theboxedcabinetstraveldownaconveyorsystemwhere workersmanuallylifteachboxofftheconveyorlinetothefloor andtransportthemtoastagingareaviaahandtruck.Workersin thisareareportedlowerback,shoulder,andneckpain.

Medical Interviews

TheNIOSHmedicalofficerinterviewed14cabinetworkersat theRedLionassemblyplant.Sevenof14employeeswereselected bymanagement.Amongtheinterviewedemployees,theaverage agewas43years(range:28to60years),andtheaveragetime employedatYorktownewas11years(range:1to36years).Ninety-threepercent(13of14)ofemployeesinterviewedreportedwork-


Results And disCussion (Continued) relatedmusculoskeletalpainordiscomfortwithinthelastyear.

Therewere11reportsofwork-relatedmusculoskeletalsymptoms involvingtheupperextremity(fingers,hand/wrist,elbow/forearm, shoulder),threeneck,threeback,andthreelowerextremity.Five ofthe14interviewedemployeeshadbeendiagnosedwithcarpal tunnelsyndrome:threeunderwentsurgeryandtwotransferredto adifferentdepartment.Ofthe14employeesinterviewedatRed Lion,sevenreportedseeingaphysicianorchiropractorwithin thepastyearforwork-relatedmusculoskeletalpainordiscomfort. Threeemployeesreportedmissingworkwithinthepastyear forwork-relatedmusculoskeletalissues.Oneemployeereported temporaryrestrictionofduties.

OSHA 300 logs

ReviewoftheOSHALogsindicatedthatmostentriesweredueto MSDs(notincludingacuteinjuriessuchasfractures,laceration, puncturesorcontusions)andthatmostMSDsinvolvedtheupper extremity.From2002through2006,57%(85of149)ofthe OSHArecordableMSDsattheRedLionassemblyplantinvolved theupperextremity.AtRedLion,OSHALogsdocumented12 MSDsin2006(5upperextremity,7back);14in2005(8upper extremity,5back,1chest);15in2004(8upperextremity,6back, 1neck);15in2003(10upperextremity,3back,1lowerextremity, 1neck);and17in2002(7upperextremity,5back,3lower extremity,1neck,1chest).

Workers Compensation Data

AtRedLion,11workers’compensationclaimswerefiledforMSDs in2006,19in2005,16in2004,21in2003,and17in2002.


ConClusions

ReCommendAtions

On-siteassessmentsandinterviewsatbothYorktownefacilities arethebasisforthefollowingconclusions.Mostworkersat bothfacilitiesareexposedtoacombinationofconcurrentrisk factorsfordevelopingupperextremityMSDs:highforce,static andawkwardposture,andrepetitivemotion.Workerswere alsoexposedtoriskfactorsforlowbackpain:lifting/forceful movements,awkwardpostures,andheavyphysicalwork.

MostMSDsreportedduringtheNIOSHmedicalinterviewsand onreviewofOSHALogsandworker’scompensationdatainvolve theupperextremity,howeverlowbackpainandinjurywasa notableproblematbothfacilities.

Theproblemswithworkstationdesignthatplaceworkersat riskforMSDinjuriesincludelowworkheights,non-adjustable workstations,andlackofspaceforcompletingthejobtasks. Theproblemswithhandtooldesignthatplaceworkersatriskfor MSDinjuriesincludeheavyweightand/orexcessvibration.The lackofanactivemaintenancereportingsystemcausesand/or exacerbatesexistingMSDsbykeepingdefectivepowertoolsand cartsinservice.

Thepreferredmethodofcontrollingergonomicshazardsisto provideengineeringcontrolsthatredesigntheworkstationand/or jobtasktoreduceoreliminatetheriskofWMSDs.Administrative controlsorpoliciesdesignedtolimitworkers’exposuresto hazardousconditionscanbeusedtemporarilyuntilengineering controlsareimplemented.Inaddition,NIOSHinvestigators recommendthatemployeesbetrainedtorecognizeergonomic hazardsandparticipateintheprocessofidentifyinghazardsand makingjobmodifications.Severalrecommendationsforjobtask andworkstationlayoutsarelistedbelow.Whileimplementing alloftheserecommendationsoveraperiodoftimeisoptimal, evenimplementingsomeofthemalongwithotheradministrative controlswouldbebeneficialinreducingworkers’riskofWMSDs.

Engineering Controls – GeneralRecommendations Generalrecommendationsforengineeringcontrolsthatwould eliminateorsignificantlyreducethephysicalstressesassociated withmaterialhandlingactivitiesarelistedbelow.


ReCommendAtions (Continued) 1. Provideadjustablescissorlifttablesandlifttruckstoreduce

bendingandoverheadreachingwhentransferringmaterial, assemblingmaterial,orsandingmaterial.Palletcarousels andcollapsiblecarouselstandsallowaccesstoloads fromvariousanglesandeliminatereachingandbending [Chengaluretal.2004].

2. Incorporateaminimumheightrangeof27.6”to29.7” (averageelbowheight)andamaximumheightrangeof51.6” to56.2”(averageshoulderheight)withrespecttoincoming andoutgoingcarts,workstations/worktables,palletized pieces,andshelvingunitstoeliminateoverheadreaching andbending[Kroemer1989].

3. Replaceoldercartswithnewcartsor,ataminimum,replace existingwheelswithnewpolyurethanewheelsthathave adoubleballraceforsmootherswivelingforturningand handling.

4. Eliminateliftingofmorethan50pounds,suchascarrying multipleblanksintheclampingprocessandtilting/lifting cartonsintheshippingdepartment.Suggestionsinclude makingmultipletripstounloadeachblankandusingabox closerthatautomaticallyclosesandsealscartons.

5. Usejigsorvicesinassemblyandsandingareastoallow therotationofworkobjectswhilekeepingupperextremity posturesneutral(Figure1).Forexample,usejigsorfixtures inthemiterpindoorlinetoeliminatemanualflippingof thedoors.

Figure 1. A jig holding and rotating the work object [Canadian Centre for Occupational Health and Safety 1998].


ReCommendAtions (Continued) 6. Reducevibrationexposurebyprovidingtoolswithlow

vibrationfrequency,properlymaintainingtools,scheduling restbreakstoallowforrecovery,andalternatingworktasks withothertasksthatdonotinvolvevibrationexposure.

7. Selectlightweighttoolstodecreasetheforcerequiredto completejobtasks.Theweightofthetoolshouldbeless than5poundsifitisusedabovetheshoulderorawayfrom thebody[Chengaluretal.2004].Iflightertoolsarenot available,provideacounterbalancedarmortoolbalancer.

8. Selecttoolswiththeproperdesignforeachtasktoimprove wristposture.Orientthetool,nottheworker.Choose toolsthateliminatewristdeviation[Chengaluretal.2004]. Ensuretoolsaresharp,lubricated,tunedandingoodrepair

Engineering Controls - Job/Area-SpecificRecommendations Job/area-specificrecommendationsthatwouldeliminateor significantlyreducethephysicalstressesassociatedwithmaterial handlingactivitiesarelistedbelow.

Mifflinburg, Pennsylvania Dimension Mill

Department 62 - Rough Mill Roughmill

● Providearamporawiderchuteforthescrapconveyorto eliminatetheneedtothrowscrappieceswiththelefthand.

● Reduceincomingstacksizeandprovideadjustabilityfor incomingskid.

● Redesignareatoeliminateleftshoulderextension.We suggestplacingtheincomingskidin-linewiththeroller conveyor,ratherthanusingthecurrentperpendicular setup.

Department 63 – Final Machining Molding

● Incorporateamaximumheightrangeof51.6"to56.2"for theoutputcarttominimizeoverheadreaching[Kroemer 1989].

● Raisecartholdingseparatorsusedtodividestacksofwood toaminimumheightrangeof27.6"to29.7"andmovethe cartclosertotheworkertoeliminateunnecessarywalking.


ReCommendAtions (Continued) Ifmovingthecartholdingtheseparatorscloserisnot

possible,placeasmallbinlocatedclosertotheworkerfor holdingsmallbundlesofseparators[Kroemer1989].

● Provideascissorliftforoutputthatcanbeusedwitha rollingtruck,especiallyinareaswhereaforkliftcannotget intoremovematerial.

Clamping ● Eliminatewristcontortionwhenpickingupblankpieces

fromconveyorandhanddippinginglue.Handdipping shouldbereplacedbytherollergluesystemalreadyinuse atthemill.

● Maketwotripswhencarryingblankcomponentsfromthe conveyortotheclampingmachine.Thiswillreducethe handforcerequiredtoliftthefullstackofmaterial.

● Unloadoneblankatatimetoreducetheweightofthe loadcarriedtobelow50pounds.

● Cuttheconveyorcontrolarmtobeflushwiththe mountingbracket(similartotheothermachine)to eliminatelacerationandbruisinghazard.

● AdjustthediverterbarontheOptisizertobringwood piecesclosertotheworkerandreducereachingtopull piecestotheedgeoftheconveyor.

● Makesureanadjustableplatformisavailableforshorter operators.

● Rotateemployeesbetweenjobstoalternatemusclegroups used,ifpossible.

Department 64 – Front Frames Frameassembly

● Tilttheframeassemblytabletoa47°angle,movingthe surfaceabout6"closertotheworkerandpreventing overreaching.Thecurrenttablehasa43°angle.

● Makecustomchockstoraisethebaseatthebackofthetilt tablesorprovidesomeothermeansofmakingthetable moreuprighttoreduceoverreachingandimprovewrist postures.

Department 65 – Door Assembly Partspullarea

● Reorganizeshelvestoaminimumheightrangeof27.6"to


ReCommendAtions (Continued) 29.7"andamaximumheightrangeof51.6"to56.2"

toreducebendingandoverheadreaching[Kroemer 1989].

Storelargestboardsinthelowestpositiontoeliminate theneedfortheworkertowalkdowntheladderwith

●

oversizedpieces.

Miteringlongpieces ●

Sanding ●

●

●

●

●

●

Providesupportfortheendsoflongerwoodpieces todecreasehandforcerequirements;arollerstand couldbeeasilymovedwhennotbeingusedforlonger pieces.

Avoidpinchgripsbyusinghandsandingtools designedaccordingtotheshapeandmaterialsanded. Workersshouldhelpdecidewhichhandlesand materialsworkbest.Hand-to-toolcouplingshouldbe roundoroblongandapproximatelya1.5”diameter [Chengaluretal.2004].

Useheight-adjustablecartsforincomingandoutgoing pieces.Aminimumheightrangeof27.6"to29.7" andamaximumheightrangeof51.6"to56.2"are suggestedtoreducebendingandoverheadreaching [Kroemer1989].

Provideshelvesforsandingblocksandothertoolsto removethemfromtheworksurfaceandminimizethe restrictionofairflowthroughtheventilationducts.

Providetiltedworksurfacesandjigstoreduce bendingandawkwardpostureswhilesanding,and reducehandforcerequirementswhileholdingthe object.

Selectlow-vibrationorbitalpneumaticsandersto reducetheriskofdevelopingcarpaltunnelsyndrome. Scheduleroutinetoolmaintenancetoensuretoolsare performingatanoptimallevelandtopreservelower vibrationaccelerationlevels.

Provideanti-fatiguefloormatstoreducelowerleg discomfortfromprolongedstanding.

Miterpindoorline ● Usejigsorvicestoallowtherotationofworkobjects

whilekeepingupperextremityposturesneutral.


ReCommendAtions Thiswillalsoeliminatemanualflippingofthedoorsand (Continued) reduceshoulderfatigue.

Red Lion, Pennsylvania Assembly Plant

Mill Incomingshelvedparts

● Placelighter,smallerpartsinhigherpositionsandlarger, heavierpartsinlowerpositionstoreducestresswhen lifting.

● Incorporateaminimumshelfheightrangeof27.6"to 29.7"andamaximumshelfheightrangeof51.6"to56.2" toreducebendingandoverheadreaching[Kroemer1989].

Flowline ● Movetherollerconveyorrailtolineupwiththefirst

machinepositiontoeliminatethecurrentmethodof manuallyliftingeachpiecefromtheconveyorandcarrying ittothefirstmachine;maketheexistingconveyorrailinto anoverflowline(Figure2).

g gress

Current main line Use as overflow

Use as main line

With lift ate for e

Figure 2. Current flow line layout (left), proposed flow line layout (right).


ReCommendAtions (Continued) ● Sloperollerconveyorsslightlydownwardbetweeneach

processlinetodecreasetheamountofforcerequiredto pushpallets.

● Donotplaceacompleteorderofmaterialononepallet betweenprocesslines.Instead,loadtheorderonseparate palletstoreducetheheight(maximumheightrangeof 51.6"to56.2")andweightofmaterials.Thedecreased weightwilldecreasetheamountofforcerequiredtopush thepallets[Kroemer1989].

● Installathickerfloorrailorangleironrailsystembetween theconveyorlineandthehole-cuttingmachinetoreduce resistanceanddecreaseamountofforcerequiredtopush cartsfromoneprocesslinetoanother(Photo10).

● Installaslopedconveyortotransfermaterial(when necessary)tothemachineinthelastposition.Ifa conveyorisnotfeasibleduetoforklifttrucktraffic,use height-adjustablecartsandleavetheorderonseparate palletstodecreaseweightandsubsequentlydecreasepush force.

● Provideheight-adjustablecartsattheendofconveyorlines toreducebendingandreachingwhencompletingthefull order.

Finishing Conveyorline

● Usehigherboxesontheconveyortocreateaminimum heightrangeof27.6"to29.7".Becauseonly2%–3%ofthe totalcabinetcomponentsarelargerandneedtositona lowerboxinordertofitintheoven,higherboxesshould beusedmostofthetime,thiselevatedheightrangewill reducebending[Kroemer1989].

● Raisetheheightoftheconveyorlineatthesectionwhere materialsareloadedandunloaded.Thiselevatedheight willreducebendingandcanbeachievedbylengthening theconveyorlegsupports.

● Storeragsandothermaterialsattablelevel,not underneaththeworktables,toreducebending.

● Useheight-adjustablecartsforincomingandoutgoing pieces.Aminimumheightrangeof27.6"to29.7"anda maximumheightrangeof51.6"to56.2"aresuggestedto reducebendingandoverheadreaching[Kroemer1989].


ReCommendAtions (Continued) Finishlinerepairarea

● Installheight-adjustabletablesateverypositionto eliminateawkwardneckandwristpostures.

● Provideventilation,similartothatattheotherrepair tables,tothecurrentfinishlinerepairtablethathasno directexhaustventilation.

Assembly ● Sequenceworktoalternatelargeandsmallcabinets.

● Replacewheelsonkitcartswithlarger,firmwheelsthat haveadoubleballraceforsmootherswiveling,turning, andhandling.

● Provideheight-adjustabletables,atleastinthefirst position,toreduceawkwardwristpostures.

● Makeworkcellslargertoaccommodatekitcartsandto allowworkerstoeasilymovearound.Buildinganassembly linewiththeseergonomicworkstationfeaturesmaybeless costlythanretrofittingexistinglines.

● Installlazysusancomponents,similartoonesintheRCB area,toprovideassemblersconvenientaccesstostaple wherenecessaryandreduceawkwardwristpostures.

● Designadoormountingfixtureforthestationarybase frontstoholdthedoorwhileitisbeinginstalled.

● Selectlightertoolswhenpossible.

Broomertable ● Supplycoiledpneumatichosesinwhichmultipletools

plugintoonelinetoeliminatetriphazardwithhoseson thefloor.

● Provideaheight-adjustabletableattheheadofthe assemblyareatoeliminatereachingdownintothe broomercabinettostaple.

● Provideone-pieceshippingboxes,insteadofmakingone fromtwosmallerboxes,reducingtheforceandstressto loadthebox.

RevolvingCabinetBase ● Designaclampstructuresimilartothepneumaticclamps

inthebroomerareatosecurelyholdRCBpartsinplace duringassembly.Aclampstructurewillreducethehand gripforcethatiscurrentlyrequired.


ReCommendAtions (Continued) ● Installstepsbetweeneachofthefiveparallelconveyor

linestofacilitatemovementbetweenthefloorandthe elevatedplatform.

Shipping Boxing

● Installaplatforminfrontoftheshelvestoeliminatethe overheadreachbyworkersplacingflattenedboxesinthe topslots.

● Useanautomaticboxclosertoeliminatemanualtilting.

Shipping ● Installshort,downward-slopingconveyorstotransition

boxedcabinetsfromconveyortofloor;severalwell-spaced, shortslopeswouldallowsmoothtransitionandeliminate liftingeverypiecefromtheconveyortothefloor.

Administrative Controls Administrativecontrolsaremanagement-dictatedworkpractices andpoliciestoreduceorpreventexposurestoergonomicrisk factors.Theeffectivenessofadministrativechangesinwork practicesforcontrollingMSDsisdependentonmanagement commitmentandemployeeacceptance.Regularmonitoringand reinforcementisnecessarytoensurethatcontrolpoliciesand proceduresarenotcircumventedinthenameofconvenienceor production.Anadvantageofmostadministrativecontrolsisthat theycanbeimplementedquicklyandeasilywithlessexpensethan engineeringcontrols.However,becauseadministrativecontrols donoteliminatethehazard,theyshouldbeconsideredtemporary solutionsforcontrollingexposuresuntilengineeringcontrolscan beimplemented.Administrativecontrolrecommendationsinclude thefollowing:

1. Rotateworkersthroughseveraljobswithdifferentphysical demandstoreducethestressonlimbsandbodyregions.

2. Schedulemorebreakstoallowforrestandrecovery.

3. Broadenorvaryjobcontenttooffsetcertainriskfactors (i.e.,repetitivemotions,staticandawkwardpostures).

4. Ensuretools/cartsarewellmaintainedandingoodrepair. Implementanactiveroutinemaintenancesysteminsteadof apassivesysteminwhichemployeesmarktoolsforrepair.


ReCommendAtions (Continued) 5. ProvidetrainingtoemployeesintherecognitionofWMSDs

andinstructioninworkpracticesthatcaneasethetask demandsorburden.Forexample,intheroughmillarea, theworkersometimestransfersthescrappiecefromthe lefthandtotherighthandandthrowsthepieceontothe scrapconveyor.Theworkershouldslidethepieceintothe scrapchuteavailableontherightside,ratherthanthrowing thepiece.Anotherexampleisintheclampingareawhere workersuseextremewristflexiontopickuppiecesto placeintheclampingmachine.Thismotionshouldbe eliminated.Theidealsolutionwouldbetoeliminatethis jobtaskanduseanautomatedprocess.

Health Care Management Healthcaremanagementemphasizesthepreventionofimpairment anddisabilitythroughearlydetection,prompttreatment,and timelyrecovery.

1. Provideeducationandtrainingtoemployeesregarding recognitionofthesymptomsandsignsofWMSDs,andthe employer’sproceduresforreportingMSDs.

2. Encourageemployeestoreportmusculoskeletalsymptoms tomanagementandseekapromptreferraltoaphysician experiencedintheevaluationandtreatmentofWMSDs. Theearliersymptomsareidentifiedandtreated,theless likelyamoreseriousdisorderistodevelop.

3. Allowhealthcareproviderstheopportunitytotourthe Yorktownefacilitiesandbecomefamiliarwithjobsandjob tasks.Beingfamiliarwithemployeejobsnotonlyassiststhe healthcareprovidertomakeinformedcasemanagement decisionsbutalsoassistswiththeidentificationof ergonomichazardsandalternativejobtasks.Oncefamiliar withthefacilities’operationsandjobtasks,thehealthcare providershouldperiodicallyrevisitthefacilitiestoremain knowledgeableaboutchangingworkconditions.

4. Modifyjobsoraccommodateemployeeswhohave functionallimitationssecondarytoWMSDsasdetermined byahealthcareprovider.

5. Donotuseimmobilizationdevices,suchassplintsor supports,topreventthedevelopmentofWMSDs.These devicesshouldbedispensedtoindividualswithWMSDs


ReCommendAtions (Continued) onlybyhealthcareproviderswhohaveknowledgeabout

thebenefitsandrisksofthesedevices.Anyimmobilization shouldbemonitoredcarefullytopreventcomplications (i.e.,muscleatrophyfromnon-use).Forexample,wrist splints,typicallywornbyworkerswithpossiblecarpeltunnel syndrome,shouldnotbewornatworkunlessthehealthcare providerdeterminesthattheemployee’sjobtasksdonot requirewristbending.Employeeswhostruggletoperform ataskrequiringwristbendingwithasplintdesignedto preventwristbendingcanexacerbatesymptomsinthewrist becauseoftheincreasedforceneededtoovercomethe splint.

6. Educateemployeestoconsultaphysicianiftheyare consideringusingdosesofnon-steroidalanti-inflammatory agents(e.g.,ibuprofen,Aleve,Motrin)abovethenon-prescriptionlevelindicatedonthemanufacturer’spackage label.Possiblesideeffectsincludegastrointestinaldistress, bleedingfromthestomachorsmallintestines,andkidney dysfunction.

Proactive Ergonomics ProactiveergonomicsemphasizesthepreventionofWMSDs throughrecognizing,anticipating,andreducingriskfactorsinthe designstagesofnewworkprocesses.Therecommendedmethodis todesignjobs,workstations,tools,andotherequipmenttomatch thephysiological,anatomical,andpsychologicalcharacteristics andcapabilitiesoftheworker.Undertheseconditions,exposures toriskfactorsconsideredpotentiallyhazardouswillbereducedor eliminated.

1. Setpoliciesthatrequireergonomicconsiderationsforany equipmenttobepurchased.

2. Performjobhazardanalysesonallnewandproposedwork processespriortoimplementationtotargetpotentialrisk factorsforWMSDs.

3. Encourageactiveinvolvementofproductionworkersin thedesignandimplementationofnewandproposedwork processes.


ReCommendAtions (Continued) Safety Committee

Thesafetycommitteeconceptemphasizestheimportanceof managementandemployeesworkingtogethertoidentifywork hazardsandproposeergonomicsolutions.

1. Encouragetheexistingsafetycommitteeconsistingof managementandemployeerepresentativestodevelop proceduresandmechanismstoevaluateergonomicsafety goalsandmonitorprogress.Thesegoalsandobjectives shouldbeorganizedintoawrittensafetyprogramthatis endorsedbymanagementandworkerrepresentativesand communicatedtoallemployees.Safetycommitteemeetings shouldbeheldonaregularbasistoevaluateprogress,assign responsibilities,andidentifypotentialproblemareas.

2. ContinueusingtheErgonomicJobHazardAnalysesand ErgonomicsReferralForms.Encourageactiveinvolvement ofworkersintheseevaluations.

3. Provideadditionaltraininginergonomicsforthemembers ofthesafetycommittee.Ifallsafetycommitteemembers cannotreceivemorecomprehensivetraining,theSafety Managershouldreceiveadditionalergonomicstraining becausehe/shehasoverallresponsibilityforthiscommittee.


RefeRenCes CanadianCentreforOccupationalHealthandSafety[1998]. CabinetManufacturing.In:OccupationsandWorkplaces.[http:// www.ccohs.ca/oshanswers/occup_workplace/cab_manu.html].

ChengalurSN,RodgersSH,BernardTE,eds.[2004].Kodak’s ergonomicdesignforpeopleatwork.2nded.Hoboken,NJ:John Wiley&Sons.

Kroemer,KHE[1989].Engineeringanthropometry.Ergonomics 32(7):767–784.

NIOSH[1997].Musculoskeletaldisordersandworkplacefactors: acriticalreviewofepidemiologicevidenceforwork-related musculoskeletaldisordersoftheneck,upperextremity,andlow back.U.S.DepartmentofHealthandHumanServices,U.S.Public HealthService,CentersforDiseaseControlandPrevention, NationalInstituteforOccupationalSafetyandHealth,(DHHS) PublicationNo.97–141.

WatersTR,Putz-AndersonV,GargA[1994].Applications manualfortherevisedNIOSHliftingequation.Cincinnati,OH: U.S.PublicHealthService,CentersforDiseaseControland Prevention,NationalInstituteforOccupationalSafetyandHealth, DHHS(NIOSH)Publication94-110.


Thispageintentionallyleftblank.

ACknowledgements And

AvAilAbility of RepoRt TheHazardEvaluationandTechnicalAssistanceBranch(HETAB) oftheNationalInstituteforOccupationalSafetyandHealth (NIOSH)conductsfieldinvestigationsofpossiblehealthhazards intheworkplace.Theseinvestigationsareconductedunderthe authorityofSection20(a)(6)oftheOccupationalSafetyand Health(OSHA)Actof1970,29U.S.C.669(a)(6)whichauthorizes theSecretaryofHealthandHumanServices,followingawritten requestfromanyemployersorauthorizedrepresentativeof employees,todeterminewhetheranysubstancenormallyfound intheplaceofemploymenthaspotentiallytoxiceffectsinsuch concentrationsasusedorfound.

HETABalsoprovides,uponrequest,technicalandconsultative assistancetofederal,state,andlocalagencies;labor;industry;and othergroupsorindividualstocontroloccupationalhealthhazards andtopreventrelatedtraumaanddisease.Mentionofcompany namesorproductsdoesnotconstituteendorsementbyNIOSH.

ThisreportwaspreparedbyJessicaRamseyandBichDangof HETAB,DivisionofSurveillance,HazardEvaluationsandField Studies(DSHEFS).Ergonomicfieldassistancewasprovided byDanielHabes.DesktoppublishingwasperformedbyRobin Smith.EditorialassistancewasprovidedbyEllenGalloway.Health communicationassistancewasprovidedbyStefanieEvans.

Copiesofthisreporthavebeensenttoemployeeandmanagement representativesatYorktowneCabinets,Inc.,andtheOSHA RegionalOffice.Thisreportisnotcopyrightedandmaybefreely reproduced.Thereportmaybeviewedandprintedfromthe followinginternetaddress:http://www.cdc.gov/niosh/hhe.Copies maybepurchasedfromtheNationalTechnicalInformation Service(NTIS)at5825PortRoyalRoad,Springfield,Virginia 22161.


This is a recommended citation for this report: NIOSH [2008]. Health Hazard Evaluation Report: Ergonomic evaluation of workers at a cabinet mill and assembly plant, Mifflinburg and Red Lion, Pennsylvania. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for

occupational safety and health topics, contact NIOSH at:

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Delivering on the Nation’s promise:

ergonomic evaluation of workers at a cabinet mill and assembly plant

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