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This thesis investigates production optimisation systems such as lean production and their consequences for the health and safety of workers. In particular it examines potential positive effects and adverse effects on stress and musculoskeletal disorders (MSDs). The thesis com-prises an extended literature survey and a field study in the manufacturing and the services sector applying lean production. It provides an extensive review of studies carried out in lean production environments in the last 20 years that aims to identify the effects of lean production (negative or positive) on occupational health and related risk factors. Thirty-six studies of lean effects were accepted from the literature search and sorted by sector and type of outcome. Lean production was found to have a negative effect on health and risk factors; the most negative outcomes being found in the earliest studies in the automotive industry. However, examples of mixed and positive effects were also found in the literature. The strongest correlations of lean production with stress were found for characteristics found in Just-In-Time production that related to reduced cycle time and reduction of resources. In-creased musculoskeletal risk symptoms were related to increases of work pace and lack of recovery time also found in Just-In-Time systems. An interaction model is developed to pro-pose a pathway from lean production characteristics to musculoskeletal and psychosocial risk factors and also positive outcomes. An examination is also made of the changing focus of studies investigating the consequences of lean production over a 20-year period. Theories about the effects of lean production have evolved from a conceptualization that it is an inherently harmful management system, to a view that it can have mixed effects depending on the management style of the organization and the specific way it is implemented. The field study was carried out in lean environments in the manufacturing and services sec-tors, namely in the electronics, beverage, and metal industry and call centres in Greece and UK. For the psychosocial factors and recording of MSD symptoms; self reported questionnaires were administrated to the workers. In total 353 workers responded to the questionnaires. Additionally qualitative data were collected through semi-structured interviews with managers and lean officials, safety officers and workers in the sample. Finally, observation visits in the companies completed the data collection process. The lean implementation level of the companies was estimated on a five-point scale, according to a validated model (Conti et al, 2006). A follow up study to collect qualitative data was possible in one company in the sample. The research hypotheses of the field study tested the relationship between job stress and MSDs with quantitative job demands, job control, performance monitoring, and the level of lean implementation. The hypotheses were partly supported in both sectors: In the service sector findings confirm that quantitative job demands are predictors of job stress, consistent with similar studies in call centres. Stress is strongly asso-ciated with MSD development. In the manufacturing sector, quantitative job demands were not predictors of job stress, neither of MSDs. Positive challenges were a mediator of job stress. Stress was not a predictor for MSDs symptoms. Mechanical exposure increased after lean implementation in manufacturing although the opposite was aimed at. Consultation of workers on lean characteristics was another mediator to MSD development. A comparison was made between manufacturing and the services sectors. Differences be-tween sectors in job demands -with the exception of learning demands that are higher in manufacturing- were not significant. Predictability on the other hand was higher in call centres. Employees in the call centres reported statistically significant more frequent MSD symptoms compared to workers in manufacturing. Stress differences were not significant among sectors whereas job satisfaction was significantly higher in manufacturing. This can partly be explained by the positive social context, job security and management commitment to have no lay offs due to lean application; that workers enjoyed in the manufacturing companies of the sample. This was not the case in the call centres. In conclusion it was not the stressors that were higher in the call centres sample but a significant number of job support and control characteristics that were reported as being higher in the manufacturing sample of the study. Analysis of the relationship between job characteristics, stress and leanness revealed a high degree of non-linearity. The best fit was achieved with quadratic curves. At low levels of lean implementation stress was increasing. At a middle level of implementation stress reached a peak after which, with advanced implementation, it decreased. This is consistent with earlier study findings. The study demonstrates that it is not so much the level of lean implementation that is important for the health & safety effects but the lean characteristics that are employed. Characteristics linked to JIT can be critical and can be associated with increased job demands and for some cases increased stress and MSD symptoms. Moreover it is the social context (management mentality and actual workers participation) in lean application that is crucial for the implications of lean work to health. Further research is needed to compare lean effects between sectors including also other services. Finally, more research is needed on alternatives to intensive systems that would have better consequences for the health & safety of workers. Ergonomics has an obligation to pro-pose work redesign that aims at sustainability for all parties.

The purpose of this thesis was to examine hand actions required of nurses and pharmacy assistants involved with chemotherapy drug administration over a work shift, and propose associated risk control strategies. There is a need to evaluate and redesign manual “pushing” and mixing of chemotherapy drugs to prevent musculoskeletal disorders and associated healthcare costs. Muscle activity of the forearm flexor and extensor muscles, and thumb forces, were measured from 5 lab nurses, 5 floor nurses and 5 pharmacy assistants who had their actions recorded throughout their shift. Lab nurses performed an average of 1.85 ± 0.48 hand efforts per min, floor nurses performed 1.62 ± 0.09 per min, while pharmacy assistants performed 5.29 ± 1.27 per min. Syringe use accounted for 17% of the pharmacy assistants’ shift and 12% each for the floor and lab nurses. The tasks of drawing fluid and manually pushing treatment represented 10% of the work day. The left forearm flexors generated the highest activity over the workday and across tasks while only resting for 6% of the workday. The high number of hand efforts, combined with prolonged durations, and lack of muscular rest show evidence of muscular overload over the course of the shift as well as illustrate that the pharmacy assistants are at higher risk for WMSD. The results may also help explain the documented injury statistics and complaints associated with the arm, hand and thumb and support the implementation of a chemotherapy robot to reduce the risk associated with tasks performed by the pharmacy assistants. Further, the findings of this thesis can act as a guide for future evaluation and research of workplaces with similar syringe and hand demands. The risk reducing strategies presented may also be applied to other jobs where hand and syringe use is repetitive and prolonged. / Thesis / Master of Science (MSc)

Work-related musculoskeletal disorders (WMSDs) continue to present a substantial personal and economic burden. Biomarkers, in providing objective measures of physiological changes, may offer advantages over current tools for WMSD risk assessment. Existing work has identified biomarkers of cartilage and muscle damage, and demonstrated responsiveness to various forms of physical activity and biomechanical loading. Here, three studies were complete to further assess the occupational relevance/utility of three selected biomarkers: Cartilage Oligomeric Matrix Protein (COMP), Interleukin-6 (IL6), and Creatine Kinase (CK). First, the effects of age, obesity, gender, and diurnal variation was investigated. Significant effects of time, age, and gender were evident, as well as some interactive effects, for COMP and CK, but not IL6. Second, biomarker levels were compared between individuals in occupations having relatively high and low WMSD risk. IL6 levels were greater in the high-risk group, while COMP levels demonstrated an oscillatory pattern, and CK levels did not vary between groups. Third, physical demands were imposed on the lumbar spine during a repetitive flexion/extension task, under conditions with different loading and frequency. IL6 levels varied significantly over time and between added load levels, while CK levels varied over time and was influenced by load and frequency. These studies demonstrate important features of biomarkers; that personal confounding factors need to be considered, that select biomarkers may be sensitive to occupational risk factor exposure, and particularly to task parameters in lifting activities involving the lower back. Further, these studies reveal important information concerning the relevance of the selected biomarkers, favorable time points for biomarker collection, and approximate biomarker levels expected between occupations and exposure to common risk factors. These results support the use of biomarkers in occupational settings for assessing exposure and WMSD risk imposed by common risk factors. Sensitivity to exposure levels is an important precursor to risk prediction, however prospective work is needed to verify predictive validity. / Ph. D.

Hairdressers’ exposure to work-related musculoskeletal disorders (WMSDs) appears to be insufficiently described in the literature. Knowledge regarding musculoskeletal disorders in this group is also sparse. The purpose of the research was to investigate the status of work-related musculoskeletal disorder cases found in Taiwanese hairdressers and to develop user-centred, strategic solutions to prevent the accumulation of musculoskeletal disorders in this group, especially newcomers to the industry. The study involved a series of investigations into the status of WMSDs for hairdressers in Taiwan as a first step towards their prevention. A hairdresser-oriented, musculoskeletal questionnaire was used to discover the risk factors associated with WMSDs and a validated, on-line, rapid, upper-limb assessment tool was used to identify critical hairdressing working postures. Improvements to the main critical hairdressing working postures identified by the first stage of the research have been addressed by an ergonomics training programme. The effectiveness of this is validated using 3D-motion analysis based on a pre- and post-test evaluation of awkward movements. A scientific approach to 3D-motion analysis has been achieved specifically by the study of the awkward working postures of the upper extremity during hair-blow-waving and hair-straightening activities. The relationship between working postures and WMSDs in various body regions is discussed. In this regard, poor posture and movement can lead to local mechanical stress on the muscles, ligaments and joints, resulting in discomfort in the musculoskeletal system, particularly the neck, back, shoulder and wrist. This research has provided a WMSDs prevention framework as a strategic method of securing a continuous improvement in the awkward working postures adopted during various hairdressing activities. Topics for further studies are suggested.

Magister Scientiae (Physiotherapy) - MSc(Physio) / Low back pain is one of the most frequent health problems and also one of the most prevalent musculoskeletal disorders. It’s the leading reason for activity limitation and job absenteeism which leads to huge economic burden on persons, society, industry and governments. Women are more susceptible to low back pain due to hormonal effects, differences in reporting of somatic symptoms and greater sensitization of pain. The aim of this study was to determine the impact of low back pain on activities of daily living and quality of life of adult women attending Moi Teaching and Referral Hospital (MTRH), Eldoret, Kenya. The following objectives were addressed, namely to determine pain intensity, functional disability and quality of life of adult women as well as to explore the activities of daily living that may contribute to low back pain. A sequential explanatory mixed method approach, comprising of a cross-sectional descriptive and explorative design for the quantitative and qualitative phases respectively, was employed in the study. A self-administered questionnaire consisting of four sections (socio-demographic information, the Nordic Musculoskeletal Questionnaire, the Oswestry Disability Index Questionnaire and World Health Organization Quality of Life Tool) was completed by two hundred and thirty-four adult women with a mean age of 38.54 years (SD=9.40). Twenty-six women participated in the focus group discussions. Results of the study indicate that 94.6% of the women had experienced low back pain in the past year while 90.1% had low back pain in the past seven days. In addition, more than half of the women (52.3%) experienced moderate pain intensity. Almost three quarters (68.1%) of the participants who experienced pain in the past year reported that low back pain prevented them from carrying out their activities of daily living. Half of the participants (50.2%) had moderate disability. A significant positive correlation was found between pain and disability (r = 0.426; p = 0.000) while a non-significant negative correlation was found between low back pain and quality of life (r = -0.058; p = 0.390). The qualitative results showed that women have difficulty in performing certain activities of daily living i.e. personal hygiene, sitting, standing and housework due to low back pain. A significant correlation was found between pain intensity, disability and quality of life. Such correlations advocate towards the bio-psychosocial model in management of low back pain. There is a need to invest in primary-based health care to include low back pain and its related risk factors, in order to advise the affected population on appropriate and essential prevention strategies. Future interventions should focus on enhancing physical health and psychosocial stress in women with low back pain.

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.

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.

Dissertation submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic, Durban University of Technology, 2010. / Background: Professional orchestral string musicians are exposed to many physical and psychological stressors due to demands placed on them from playing their instruments. The prevalence of performance-related musculoskeletal disorders (PRMD’s) in this highly skilled group of individuals has been investigated internationally, consistently showing a high injury rate. There is however, a paucity of literature documenting the prevalence of musculoskeletal injuries in South African professional orchestral string players. It is hypothesized that South African trained orchestral string musicians may be at a greater risk for PRMD development due to the unique training and performance environments encountered in this country. Objectives: This study aimed to determine the demographic and injury profile; prevalence rate of current injury and risk factors for musculoskeletal injury in South African professional orchestral string musicians. Method: The study utilized a self administered quantitative questionnaire distributed to all string players in the three professional orchestras in South African in a semi-supervised fashion. SPSS version 15.0 (SPSS Inc., Chicago, Illinois, USA) was used to analyze the data. A p value < 0.05 was considered as statistically significant. iv v Results: There were 27 respondents, with the average participant being a Caucasian, right handed, non-smoking female, 37.11 years of age, 1.5631 meters tall, with a weight of 62.96 kilograms (BMI = 25.768) who exercised regularly (primarily in the gym). A bachelors degree in Music was the most commonly awarded qualification, obtained between the years 2000 and 2009, from a University outside of the Republic of South Africa. The prevalence of PRMD’s in the sample was 63% (n = 17), with a 95% confidence interval of 42.4% to 80.6%.In this study there was a high rate of injury (6.53 PRMD’s per player over a 12 month period), equating to 111 reported injuries in a population of 27 string players. The upper back (defined as the area between the shoulder blades) was the most commonly injured part of the body (77.8%, n = 21), followed by the upper extremity, mainly the shoulder (70.4%, n = 19). No statistically significant relationships were found in determining and confirming expected risk factors in the string players. Conclusion: Professional orchestral string musicians in South Africa suffer from a high rate of injury which is comparable to international studies of the same nature

In this thesis we look for potential chronic inflammation biomarkers because studies have shown that farmers with musculoskeletal disorders might be affected by the environment to develop musculoskeletal disorders. Animal farmers are highly exposed to dust, aerosols, molds and other toxins in the air and environment leading to musculoskeletal disorders, respiratory disorders, airway symptoms and febrile reactions. There is reason to believe that the farmers have a constant or chronic inflammation that develops into musculoskeletal disorders. By using a proteomic approach with Two-dimensional Gel Electrophoresis and silver staining our goal was to find biomarkers by quantifying protein spots that differ significantly from farmers with musculoskeletal disorders compared to rural controls. In our study we found 8 significant proteins, two from Alpha-2-HS-glycoprotein, one from Apolipoprotein A1, three from Haptoglobin, one from Hemopexin and 1 from Antithrombin. All 5 proteins are involved in inflammation response in some way and some proteins are linked to chronic inflammation. Out of the 5 proteins Alpha-2-HS-glycoprotein, Apolipoprotein A1 and Hemopexin seem like the most likely proteins to investigate further as potential inflammation biomarkers.