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Arbetslivet ställer allt högre krav på stresstolerans när kraven på flexibilitet ökar. Inom vissa yrkesområden har hög stresstolerans av naturliga skäl alltid varit ett grundläggande krav. Då stresstolerans förefaller mångfacetterat var syftet att göra en kvalitativ undersökning om hur professionella bedömare vid rekrytering och urval till yrken och yrkesutbildningar med höga krav på stresstolerans definierar och kartlägger denna egenskap samt vilka metoder de använder. Datainsamlingen genomfördes genom sju halvstrukturerade intervjuer med rekryterare samt psykologer knutna till försvarsmakten, flyg, brandförsvar, polis, räddningsverksamhet och kustbevakning. Resultatet som tolkades med induktiv tematisk analys, visar att detta genomförs med hjälp av typbestämning av stresstolerans, hypotesskapande testning, hypotesprövande helhetsbedömning samt kontroll av inre och yttre resurser. Slutsatsen är att stresstolerans betraktas både som en stabil och en situationsbunden egenskap och att bedömaren i huvudsak fungerar som instrument. Fler studier behövs genomföras, framför allt inom andra yrkesområden, för att säkerställa att stresstolerans inte bedöms enbart med fingertoppskänsla.

Attempting to enhance their productivity or improve working conditions, many businesses have adopted organizational change programs that involve a participatory component. To attain a comprehensive understanding of these change programs we need to investigate the influence of social factors such as power, the impact of local and global contexts, and the role that agency plays in these programs. Further, because organizational programs do not unfold linearly and the contexts in which they are embedded continually evolve, it is crucial to employ an approach that allows studying organizational programs over time. Attending to these considerations enables the production of narratives of organizational change that are congruous with the dynamism of organizational life. This dissertation explores the dynamics of an organizational program in a particular type of occupational health and safety program, which emphasizes employee involvement: participatory ergonomics (PE). Participatory ergonomics, intended to reduce workers’ exposures to work-related musculoskeletal disorders, draws on the input of small groups of labour and management representatives called ergonomic change teams (ECTs) to address exposure to hazards that may lead to musculoskeletal disorders. The dissertation’s examination of an organizational change program consists of an analysis of PE programs in two workplaces: a courier depot and a manufacturing plant. The dissertation’s investigation of the PE programs is based primarily on observations, which were gathered longitudinally as the ECTs endeavoured to make ergonomic changes, and fifty-five semi-structured interviews, which were carried out with ECT members and other key informants who were not members of the ECTs. Data collection occurred during 48 months in the manufacturing setting; in the courier company, collection took place during a 30-month period. The dissertation’s analysis is informed by negotiated order and critical theory lenses. Negotiated order considers social order as an ongoing process and draws attention to the activities of individuals and groups, and the manner in which they influence the dynamics of social life. In regard to organizational programs, it rejects the idea that they unfold independently of actors’ efforts; rather, it considers them as products of individuals’ attempts to establish and maintain the necessary agreements to ensure their operation. Critical theory, as it pertains to occupational health, identifies the constraints that shape working conditions and links these with the uneven distribution of power in the workplace and production imperatives. The dissertation addresses the following general research questions: What actions were undertaken by individuals to ensure the PE programs functioned and continued? How did the organizational and societal context enable or constrain the pursuit of PE program activities? The presentation of the findings begins with an account of the problem-solving processes used in both of the settings, an overview of the types of knowledge that were used, and a description of the actors’ access to knowledge. In each setting, design parameters, production pressures, the nature of the knowledge required to design solutions, and the differential distribution of that knowledge among workplace personnel influenced (a) the effectiveness of the ECTs’ solution building activities, (b) the design process, and (c) the nature and degree of participation by the teams’ worker members. The dissertation then proceeds to an examination of the implementation process. It explores how this process is affected by the organizational context, in particular the ECTs’ limited authority as agents of change, and shows that the minimal authority they possessed prompted the ECTs to select an array of strategies to accomplish their work. These strategies often took the forms of persuasion, persistence, and enlisting the assistance of other personnel. Extending the discussion of implementation, the dissertation then focuses on the division of labour within the ECTs as they carried out their activities. In both settings, implementation activities were unevenly distributed among the ECTs’ membership; they were predominantly carried out by managerial personnel. Both the programs’ functioning and the participation of worker representatives were influenced by the interplay among three main factors: the type of activities that needed to be carried out, workplace hierarchy, and stance, or participants’ views about their ability to act effectively. The discussion of the PE programs then proceeds to an examination of whether the programs were supplied with the resources required to continue over time. The outcomes differed: in Courier Co. the program was discontinued, whereas in Furniture Co. it was maintained. The discussions investigate how PE program continuation was affected by the program supporters’ activities and shaped by conditions both internal and external to the organization. Foremost among these conditions were management’s view of health and safety and the occupational health and safety regulatory framework. The dissertation’s examination of the PE programs over time provides evidence that the functioning and the degree of worker involvement in participatory occupational health programs are conditioned by structural and interactional elements. The programs were shaped by an uneven distribution of power, limits on access to knowledge and scarce resources, and actors’ divergent interests and their capacities to act in accord with these interests. The final chapter of the dissertation reviews the key findings and examines common themes that arose across the workplaces. The dissertation concludes with observations on several topics: the challenges of evaluating program outcomes in settings such as occupational health and safety; the lessons that participatory ergonomics practitioners can take from the study’s findings; and suggestions for possible avenues of future research.

As awareness of the costs of workplace injury and illness continues to grow, there has been an increased demand for effective ergonomic interventions to reduce the prevalence of musculoskeletal disorders (MSDs). The goal of ergonomic interventions is to reduce exposures (mechanical and psychosocial); however there is conflicting evidence about the impact of these interventions as many studies produce inconclusive or conflicting results. In order to provide a clearer picture of the effectiveness of these interventions, we must find out if methodological issues, particularly statistical power, are limiting this research. The purpose of this study was to review and examine factors influencing statistical power in ergonomic intervention papers from five peer reviewed journals in 2008. A standardized review was performed by two reviewers. Twenty eight ergonomic intervention papers met the inclusion criteria and were fully reviewed. Data and trends from the reviewed papers were summarized specifically looking at the research designs used, the outcome measures used, if statistical power was mentioned, if a rationale for sample size was reported, if standardized and un-standardized effect sizes were reported, if confidence intervals were reported, the alpha levels used, if pair-wise correlation values were provided, if mean values and standard deviations were provided for all measures and the location of the studies. Also, the studies were rated based on the outcomes of their intervention into one of three categories (shown to be effective, inconclusive and not shown to be effective). Between these three groupings comparisons of post hoc power, standardized effect sizes, un-standardized effect sizes and coefficients of variation were made. The results indicate that in general, a lack of statistical power is indeed a concern and may be due to the sample sizes used, effect sizes produced, extremely high variability in some of the measures, the lack of attention paid to statistical power during research design and the lack of appropriate statistical reporting guidelines in journals where ergonomic intervention research may be published. A total of 69.6% of studies reviewed had a majority of measures with less than .50 power and 71.4% of all measures used had CVs of > .20.

Approximately 80% of the population will experience low-back pain within their lifetime. Significant research efforts have focused on compressive loading as an injury mechanism that could lead to low-back pain and injury. However, the influence of shear loading, and its relationship to vertebral tissue tolerances as well as modulating factors for these tolerances have not been studied as extensively. The primary objective of this thesis was to produce a series of investigations that begin to determine the roles of different modulating factors such as posture, compression, bone density, bone morphology, and repetitive load magnitude on measured vertebral joint shear failure tolerances. The thesis comprises four independent studies using in vitro mechanical testing, imaging modalities, and finite element modeling. Each of the in vitro studies within this thesis used a validated porcine cervical model as a surrogate for the human lumbar spine. The first study employed in vitro mechanical testing to investigate the combined roles of flexion/extension postural deviation and compressive load on the measured ultimate shear failure tolerances. Peripheral quantitative computed tomography scans of the pars interarticularis and measurements of vertebral bone morphology were used in the second investigation along with in vitro mechanical testing to identify the morphological characteristics that can be used to predict ultimate shear failure tolerances. The influence of sub-maximal shear load magnitude on the cumulative shear load and number of loading cycles sustained prior to failure were investigated with in vitro mechanical testing in the third study. Finally, a finite element model of the porcine C3-C4 functional spinal unit was used to investigate the plausibility of hypotheses, developed from previous research and the findings of the first investigation for this thesis, surrounding alterations in measured ultimate shear failure tolerances as a function of changes in facet interaction. Results from the first investigation showed that there was no statistically significant interaction between postural deviation and compressive force on ultimate shear failure tolerance. However, ultimate shear failure tolerance was reduced (compared to neutral) by 13.2% with flexed postures, and increased (compared to neutral) by 12.8% with extended postures. Each 15% increment (up to a maximum of 60% of predicted compressive failure tolerance) in compressive force was met with an average 11.1% increase in ultimate shear failure tolerance. It was hypothesized that alterations in flexion/extension posture and/or compressive force altered the location for the force centroid of facet contact. These changes in the location of facet contact were hypothesized to produce subsequent changes in the bending moment at the pars interarticularis that altered the measured ultimate shear failure tolerance. The three leading factors for calculating of measured ultimate shear failure tolerance were the pars interarticularis length for the cranial vertebra, the average facet angle measured in the transverse plane, and cortical bone area through the pars interarticularis. A bi-variate linear regression model that used the cranial vertebra’s pars interarticularis length and average facet angle as inputs was developed to nondestructively calculate ultimate shear failure tolerances of the porcine cervical spine. Longer pars interarticularis lengths and facets oriented closer to the sagittal plane were associated with higher measured ultimate shear failure tolerances. Fractures observed in this investigation were similar to those reported for studies performed with human specimens and also similar to reported spondylolitic fractures associated with shear loading in humans. This provided additional evidence that the porcine cervical spine is a suitable surrogate in vitro model for studying human lumbar spine mechanics. Altered sub-maximal shear load magnitude create a non-linear decrease in both the number of cycles and the cumulative shear load sustained prior to failure. These findings suggested that estimates of cumulative shear load should assign greater importance to higher instantaneous shear loads. This was due to an increased injury potential at higher instantaneous shear loads. Cumulative load sustained prior to failure was used to develop a tissue-based weighting factor equation that would apply nonlinearly increased weight to higher shear load magnitudes in estimates of cumulative shear load. A finite element model of the porcine C3-C4 functional spinal unit was created, and simulations were performed using similar boundary conditions as the comparable in vitro tests, to assess the plausibility of the moment arm hypothesis offered within the first investigation of this thesis. Moment arm length between the force centroid of facet contact and the location of peak stress within the pars interarticularis was increased for flexed postures and decreased for extended postures. Alterations in moment arm length were larger for postural deviation than compressive force, suggesting a secondary mechanism to explain the observed increase in shear failure tolerance with higher compressive loads from the first investigation. One such possibility was the increase in the number of contacting nodes with higher compressive forces. Alterations in moment arm length were able to explain 50% of the variance in measured ultimate shear failure tolerances from the first study. Thus, the finite element model was successful in demonstrating the plausibility of moment arm length between the force centroid of facet contact and the pars interarticularis as a modulator of measured ultimate shear failure tolerance. This thesis has developed the basis for understanding how failure of the vertebral joint exposed to shear loading can be modulated. In particular, this thesis has developed novel equations to predict the ultimate shear failure tolerance measured during in vitro testing, and to determine appropriate weighting factors for sub-maximal shear forces in calculations of cumulative shear load. Evidence presented within this thesis also provides support for the long-standing moment arm hypothesis for modulation of shear injury potential.

Current trends in industry are leaning towards specialized production systems and sedentary computer work tasks that are associated with low and less varying mechanical exposures. It has been suggested that physical variation is an effective intervention to reduce local fatigue and potentially musculoskeletal disorders. However, little is known in how the differences between physical variation patterns affect physiological and psychophysical responses. The general purpose of this thesis was to explore the biophysical effects of varying force amplitudes using forces, cycle times, and duty cycles that are relevant to occupation and longer-term health outcomes. Fifteen healthy males performed an elbow extensor sustained isometric exertion at 15% Maximum Voluntary Force (MVF), an intermittent contraction between 0% MVF and 30% MVF (On/Off), an intermittent contraction between 7.5% MVF and 22.5% MVF (MinMax), an intermittent contraction between 1% MVF and 29% MVF (1 Percent), and a sinusoidal contraction between 0% and 30% MVF (Sinusoidal). Eight commonly used measurement tools recorded biophysical responses as participants performed each condition for up to 60 minutes or until exhaustion, during 60 minutes recovery, and at 24 hours post-exercise. Measures included electromyography of the triceps muscles, mechanomyography, blood flow, heart rate, stimulated tetani and twitch responses, maximum exertions, and perceived exertion. The rate of response during exercise and comparisons between baseline, cessation, and recovery values were used to assess fatigue responses. This research shows that implementing physical variation, at the same mean amplitude, may provide reduced fatigue rate and that the magnitude and shape of the intermittent force variations affect exercise and recovery measures. Time varying forces may therefore provide the necessary mechanism to encourage beneficial physiological responses that would improve long-term health and well being of workers at low-load jobs.

<p>Den snabba generella eltekniska utvecklingen har även satt sina spår i pumpbranschen. Detta har lett till en mängd nya funktioner och med det ett nytt uppförande hos pumparna. Detta har lett till missförstånd mellan användare och pump. Användaren tror till exempel att pumpen är trasig då den egentligen är automatiskt stoppad, vilket får följden att pumpen skickas på service även då den inte är trasig.</p><p>Syftet med examensarbetet är att utveckla ett HMI med hög användbarhet som ser till att användaren inte missförstår pumpens nya agerande.</p><p>Genom fältstudier erhölls kunskap om användaren, arbetsmiljön, arbetssättet och utrustningen. Detta lade grunden till hela arbetet. Informationen som samlades in analyserades ur ett användbarhetsperspektiv, och sammanställdes i en kravspecifikation och i Holtzblatts (1998) arbetsmodeller.</p><p>Det slutgiltiga resultatet har arbetats fram genom konceptutveckling. Det som började som en idé har sedan genom vidareutveckling resulterat i sex koncept. Koncepten har sedan utvärderats ur ett användbarhetsperspektiv. Under utvärderingen är hänsyn inte tagen till varken ekonomi eller teknik. Det som koncepten har gemensamt är således att de alla har hög användbarhet.</p><p>Utvärderingen visar också att det för 2600-serien finns en uppdelning användarna emellan. En typ av användare med specifika krav för de små pumparna och en annan typ av användare med andra specifika krav för de större pumparna. För användarna av de små pumparna önskas en enkel lösning, som endast visar om pumpen går eller inte. Här passar alltså en lösning med enkla dioder där en färgkodning visar pumpens status. För de större pumparna finns istället ett intresse för en mer sofistikerad lösning. Här önskas fjärrlarm och loggad data, vilket gör det mer lämpligt med digitala lösningar.</p> / <p>The fast development within electronic technology has given the pump a new appearance. This has led to misunderstandings between the user and the pump. For example, the user thinks the pump is broken when it is in an auto stop mode. The consequence of that is that the pump is sent for maintenance even though it is not broken.</p><p>The purpose of the master thesis is to develop a HMI with good usability, where the HMI makes sure the user will not misunderstand the new appearance of the pump.</p><p>Field studies were made to understand the users, their working environment, the way they work and also the equipment. The studies became the base on which the thesis relies on. The information that were collected in the field studies were carefully analyzed through a usability perspective. The results were presented as requirements of usability.</p><p>The methodologies of concept development were used to create a number of HMI solutions. What once started as many ideas has now ended up as six concepts of a HMI with good usability. The concepts were all evaluated in usability. The work of this project does not cover the considerations of economy and technology.</p><p>The evaluation shows that the users of the 2600 series can be divided in to two major groups; the user of the small pump and the user of the big pump. The users of the small pump prefer a simple solution that only shows whether the pump is running or not. Instead, the users of the big pump prefer a more sophisticated solution, with alarms, specified indicators and instruction of repairs.</p>

INTRODUCTION: Older people are a vulnerable population for falls and the risk may be increased by unfamiliar hospital environments. Using a mixed method ergonomic approach to acknowledge the complexity of contemporary hospital environments, this thesis aims to explore the associations between patient characteristics and environmental causal factors of in-patient falls for older people. METHODS: A series of three exploratory pilot studies were carried out, followed by two large scale research projects using nationally collected data from patient incident reports and overnight bedrail audits. The mixed method approach included; secondary data analysis, interviews, surveys, and audits. MAIN FINDINGS: 1. Patients in care of older people wards have different characteristics compared to same age peers in other wards, with higher levels of frailty and confusion. 2. Bedrail use was found to rise with increasing level of confusion which is against general guidance. Staff rationales for bedrail use suggested an underlying intent to restrain confused patients. 3. Up to 92% of patients falls were reported to be un-witnessed. This may be explained by only 24% of patient beds being visible from nursing stations. 4. There were significant differences found in the fall locations between patients who were described as frail and those who were described as confused. CONCLUSION: Patients in care of older people wards have a different set of characteristics compared to same age peers in other wards. This suggests that they will have different requirements for fall prevention in terms of layout, visibility, equipment use and facilitating independence. Further research should focus on designing wards for care of older people patients which improve visibility, layout and way-finding to toilets and investigate whether these design improvements will facilitate independent movement and prevent patient falls.

The project has been done in cooperation with Schenker Åkeri AB in Sweden, Halmstad. The project is based on an inspection made by Arbetsmiljöverket, where they found minor shortcomings with distribution of goods for the employees. The project is an investigation of the drivers’ working environment. Schenker Logistics is one of the world's leading providers of integrated logistics services. Schenker Åkeri AB is a subsidiary to Schenker Logistics and transports 2.4 million tons of goods yearly. The project started with a background study to evaluate drivers working environment. We have studied goods receptions, the working environment, strain injury and injury mechanisms. Methods used was observations, tests, questionnaire surveys and ergonomic and biomechanical calculations. One result of the study is a working model, which gives recommendations for the maximum weight a driver should push and pull. A truck evaluation was done to exam the need for new technical equipment. An ergonomic investigation was done to investigate the drivers’ working tasks. A questionnaire was given to the drivers to evaluate their working environment and tasks. The questionnaire involved questions about stress, handling of goods and technical equipment. Together with Schenker Åkeri AB in Halmstad, an action plan was made. This action plan will be handed over to Arbetsmiljöverket by Schenker.

Uppsatsen beskriver företagskulturen i företaget Helmia Bil. Helmia Bil har verksamheter på flera orter i Värmland och avståndet mellan ledning och anställda är utspritt. Sjukskrivningstalen är relativt låga inom hela organisationen men speciellt låga i Sunne och Torsby. Med anledning av det uppkom mitt intreese för att studera företagskultuern inom företaget. Helmia bil ingår i en större undersökning om "långtidsfriska" företag som Karolinska institutet gör. De menar att vi ska lära av dessa företag som har låga sjukskrivningstal. Syftet med studien var att undersöka om företagskulturen skiljer sig åt mellan orterna Sunne/Torsby och Karlstad. Jag hade en förförståelse att företagskulturen är starkare i Sunne/Torsby där företaget en gång startade. Företaget köpte Volvohandeln i Karlstad för tio år sedan (1997). Min hypotes var att företagskulturen är starkare och mera levande i Sunne/Torsby. För att uppnå syftet med undersökningen har kvalitativa intervjuer gjorts. Anställda i Sunne, Torsby och Karlstad har intervjuats. Jag ville se vilka drivkrafter som finns, hur anställda upplever sin arbetsmiljö, hur kommunikationen fungerar, hur man upplever företagets ställda mål och affärsidé. Jag ville också se hur väl anställda i företaget kände till grundare och företagets värdegrund. Materialet har sedan analyserats och transkiberats med utgång från Strauss och Corbin. Resultatet visade att företagskulturen är starkare och mer levande i Sunne/Torsby. Olika faktorer påverkar företagskulturen. Några av dessa är: det geografiska avståndet mellan orterna, hur internkommunikationen fungerar, ledarskapet, kunskap om grundare och företagets värdegrund. Som bakgrund till undersökningen ligger teorier om Rutiner och Ritualer, Organisation och styrning, Makt och ledarskap och Medarbetarskap och samarbete.