Les troubles musculo-squelettiques (TMS) sont la principale cause d’absentéisme au travail. Ils représentent un coût économique important, mais ils ont aussi de graves conséquences au niveau individuel – douleurs persistantes, limitations fonctionnelles ou perte d’emploi. De nombreuses expositions professionnelles ont déjà été mises en évidence pour expliquer la présence de ces symptômes, mais certaines relations restent encore à confirmer.L’objectif de ce travail de thèse était d’étudier l’association entre les facteurs professionnels, en particulier les facteurs physiques, et les TMS au niveau des coudes et des genoux. Les TMS au niveau des coudes ont été étudiés à travers la prévalence des symptômes aux coudes et des épicondylites, et l’incidence des épicondylites. Les douleurs aux genoux ont été étudiées à travers l’incidence des douleurs de courte ou de longue durée. Ce travail a nécessité l’utilisation de méthodologies spécifiques, en particulier les diagrammes causaux et les méthodes de gestion des données manquantes qui seront explicitées dans une partie théorique. La population dans ce travail de thèse était une cohorte de 3 710 sujets représentatifs des actifs des Pays de la Loire. Ils ont été recrutés entre 2002 et 2005 et ont été suivis entre 2007 et 2010. A chaque phase, un questionnaire sur les conditions de travail a été rempli par les participants et un examen clinique qui évaluait la présence de troubles musculo-squelettiques a été réalisé par des médecins du travail volontaires. En conclusion, les facteurs professionnels mis en évidence étaient globalement des facteurs de mouvements répétitifs impliquant les articulations étudiées (torsion des poignets et flexion/extension des coudes ou le fait de s’agenouiller). Le travail en force (manipulation de charges, efforts physiques importants) et les tâches répétitives ont également été mis en évidence comme prédicteurs de TMS ultérieurs / Musculoskeletal disorders (MSDs) are a leading cause of absenteeism from work. In addition to their major economic impact, musculoskeletal disorders have important consequences on individuals with the persistence of pain, disability and potential job loss. Many occupational exposures were highlighted to explain these symptoms, but certain relationships between occupational exposures and MSDs should be examined further.The aim of this thesis is to investigate the association between occupational exposures, especially biomechanical exposures, and elbow or knee MSDs. The elbow MSDs are studied with the prevalence of symptoms and lateral epicondylitis, and the incidence of lateral epicondylitis. The incidence of knee pain is examined according to its duration.The methodologies and theories appropriate to this type of work is briefly presented - a section focuses on the causal diagrams and methods of handling missing data.The population used is a cohort of 3710 subjects representative of the French workforce. Subjects were selected from workers undergoing a mandatory annual health examination between 2002 and 2005 and were followed between 2007 and 2010. For each phase of the study, a self-administered questionnaire on working conditions was completed and a clinical examination was performed in order to evaluate the presence of musculoskeletal disorders. In conclusion, repetitive movements involving the joints studied such as wrist-twisting, flexion/extension of the elbows or kneeling are associated with MSDs. The notion of force, such as load handling and physical exertion, and the notion of repetitive tasks are also identified as predictors of subsequent MSDs

Introduction: Musculoskeletal disorders constitute the greatest cause of sickness absence from work. Despite research and efforts at rehabilitation, sickness absence due to these disorders has not decreased, but has instead increased, particularly in women. Clients’ perceptions of care and rehabilitation, i.e. knowledge generated from a lay perspective, is a neglected area of research. This thesis deals with lay experiences of rehabilitation following sickness absence due to back, neck or shoulder problems, termed musculoskeletal disorders (MSD). Aim: The overall aim was to examine hindering and promoting processes in rehabilitation after sickness absence due to MSD from a lay perspective. Specific aims were to study how lay persons experience rehabilitation agents and rehabilitation activities (paper I), how they describe themselves and their experience in relation to work (paper II), the significance of the private arena regarding return to work (paper III), and how clients who have experienced sickness absence due to MSD perceive contact with rehabilitation agents (paper IV). Method: The study population in the four papers is part of a cohort of persons living in the same municipality and who in 1985 were aged 25-34 years and were sick-listed due to back, neck or shoulder diagnoses for 28 days or  more, n=213. During 1995, 148 persons in the cohort responded to a questionnaire, and in 1997-1998, 20 of these persons were interviewed concerning their experiences with rehabilitation. In papers I, II and III the qualitative method of Grounded Theory was used with a focus on creating an empirically-based theory concerning the area under study. Data collection was strategic and analysis of the tape-recorded interviews was done on a continual basis. How previously sick-listed persons experienced contact with professional rehabilitation agents in t he health care sector and social insurance office was investigated in paper IV. Factor analysis and multiple regression analysis were used to analyse the data in this study. Results: The interview study shed light on lay persons’ experiences with medical, social and work-related measures in rehabilitation, their perceptions of rehabilitation actors and family members in relation to rehabilitation, and their self-presentations. The descriptions of lay persons concerned three arenas, the health care arena, the occupational arena, and the private arena. Dilemmas and difficulties in these arenas were described, such as handling the duty to work, experiencing domestic strain, and the experience of lacking socioemotional support from significant persons during the rehabilitation process. In paper I some ideal types of rehabilitation agents emerged from the interviewees’ descriptions concerning the health care arena, and we called these the routine bureaucrat, the empathic administrator, the distant technician, and the professional mentor. The latter agent was requested and was described as a person who could provide socioemotional support, who had professional competence, and who could function as a unifying link during the rehabilitation process. The results from paper II showed that in their self-presentations, the interviewees expressed having a duty to work and that there were differences in how they handled this sense of duty. The selfpresentations contained descriptions of work as a part of personal identity and could be summarised in the following ideal types: the work manic, the workhorse, the workaholic and the relaxed worker. The latter used a strategy that can be considered to promote rehabilitation in that the individual himself/herself had control over his/her work and worked in accordance with his/her own needs rather than those of others. Paper III focused on the private arena. Different patterns were found in the experiences of men and women. Women related that their responsibility for the home and domestic work seldom left any time for themselves, including any time for rehabilitation. Men more often reported having time for themselves that could be used for leisure activities and rehabilitation. Some of the women said that they lacked socioemotional support from their partner and that they had a great deal of responsibility for housework, which seemed to be a hindrance in returning to work after sickness absence. Furthermore, these women, like most of the men, had little education, which could make finding other work alternatives more difficult. Based on the interviews, a hypothesis was developed regarding domestic strain that is related to the distribution of domestic work, the distribution of responsibility for the home, and the quality of the marital relationship. Paper IV dealt with clients’ perceptions of contact with rehabilitation agents in health care and the social insurance office. Three latent dimensions were found in the respondents’ ratings of these contacts: supportive treatment, distant treatment, and empowering treatment. Sex, disability pension status, mental health and diagnostic group were significantly related to how these dimensionswere rated. Women perceived the treatment from both types of rehabilitation agents as more supportive than men. Contact with the social insurance offices were rated higher by persons with disability pensions than by those who had returned to work. Men rated their contact with rehabilitation agents at social insurance offices high on the dimension of distant treatment. Respondents with mental health problems rated the contact as distant for both types of rehabilitation agents, but contact with health care was also scored low on the supportive dimension. Finally, respondents with neck/shoulder diagnoses rated contact with rehabilitation agents in health care as more empowering than was done by persons with back diagnoses. Conclusions: From a lay perspective rehabilitation following sickness absence due to MSD occured in three arenas, the health care arena, the occupational arena and the private arena, where the quality of relationships both with rehabilitation agents, persons at work and in one’s private life was described as important regarding the rehabilitation process. This thesis also showed that both sex and health were important factors regarding how lay persons’ perceived contacts with rehabilitation agents during the rehabilitation process following sickness absence due to MSD.

<p>This study aimed at identifying the factors contributing towards work related neck pain amongst university administrative staff, its impact on everyday life activities and in turn its prevalence. A quantitative descriptive cross sectional study design was used amongst the administrative staff at the University of The Western Cape, South Africa. Data collection was carried out with the help of a questionnaire which was administered by the researcher in person. Data was analysed with both descriptive and inferential statistics using SPSS and SAS for windows. Chi-square test and logistic regression analysis was done. The results of this study revealed a very high prevalence of work related neck pain amongst university administrative staff. </p>

Both spinal pain and temporomandibular disorders (TMD) commonly occur in the general population. Previous studies demonstrate neurophysiologic and biomechanical couplings between the trigeminal and cervical regions. This investigation tested the null hypothesis of no relationship between spinal pain (neck, shoulder and/or low back) and TMD, by using questionnaires and clinical examinations of the jaw function. In an age- and sex-matched case-control study, the specific aim was to compare the prevalence of signs and symptoms of TMD among cases with long-term spinal pain and controls without spinal pain. The results showed that subjects with spinal pain had signs and symptoms of TMD significantly more often than did controls. The associations remained after excluding all participants with jaw pain. Furthermore, the comorbidity pattern was similar, regardless of location of spinal pain. In a cross-sectional study, the specific aim was to test whether there is a reciprocal cross-sectional dose-response-like relationship between spinal pain and TMD. Two different designs were used, one with frequency/severity of spinal pain as independent variable, and the other, with frequency/severity of TMD symptoms as independent variable. The analysis showed increasing odds for presence of TMD symptoms with increasing frequency/severity of spinal pain, and increasing odds for presence of spinal pain with increasing frequency/severity of TMD symptoms. In a case-control study within a 2-year prospective cohort, the specific aim was to test whether there is a reciprocal temporal relationship between signs and symptoms in trigeminally, and symptoms in spinally, innervated areas. Incidence of symptoms in these areas was analyzed in relation to presence of spinal pain, headaches, and signs and symptoms of TMD at baseline. The main findings were that presence of signs of TMD at baseline increased the onset of spinal pain and symptoms in the trigeminal area, and that spinal pain increased the onset of symptoms in the trigeminal area. An augmentation effect between the significant baseline variables was observed for the incidence of headaches and jaw pain. In conclusion, the investigation demonstrated a cross-sectional and temporal relationship between spinal pain and TMD; thus, the null hypothesis was rejected. The results indicate common pathophysiological mechanisms in the development of spinal pain and TMD. The comorbidity and reciprocal influence that were found call for an integrated and multidimensional approach in the management of individuals with long-term spinal pain and TMD.

Musicians are a high-risk occupational group for musculoskeletal disorders. Often manifesting in muscle tension, pain and paresthesia, musculoskeletal disorders can drastically affect comfort, mentality and endurance while performing. This study sought to examine the effects of electromyography (EMG) biofeedback training in reducing musculoskeletal symptoms in music performance. The subjects were university-level violinists and cellists. Over a period of 2-4 weeks, all participants underwent EMG biofeedback training while performing their instrument using audio feedback. No significant results were found, but patterns of decreased muscle tension and increased performance comfort and endurance were observed.

<p>This study aimed at identifying the factors contributing towards work related neck pain amongst university administrative staff, its impact on everyday life activities and in turn its prevalence. A quantitative descriptive cross sectional study design was used amongst the administrative staff at the University of The Western Cape, South Africa. Data collection was carried out with the help of a questionnaire which was administered by the researcher in person. Data was analysed with both descriptive and inferential statistics using SPSS and SAS for windows. Chi-square test and logistic regression analysis was done. The results of this study revealed a very high prevalence of work related neck pain amongst university administrative staff. </p>

The aims of the thesis were (i) to investigate the impact of repetitive low-intensity work exposure on proprioception and (ii) to examine effects of muscle stretching (especially sensory effects and effects on muscle nociception) and to relate its application to the prevention, alleviation and/or treatment of work-related neuromuscular disorders. The effects of low-intensity repetitive work on the shoulder proprioception were tested in healthy subjects. The effect of working time on the retention of subjective fatigue and their relation to changes in proprioception, and the immediate effect of stretching on shoulder proprioception were investigated. A new method to test the stretchability of the rectus femoris muscle was investigated for reliability and validity and used to assess the effects of a two-week stretching regimen on range of motion and on subjective stretch sensation. Finally, the interactions between innocuous muscle stretch and nociceptive chemical stimulation on discharge behavior of nociceptive dorsal horn neurons in the feline spinal cord were explored. The main findings were as follows: 1) The repetitive low-intensity work to fatigue diminished the shoulder proprioception; the working time as well as the retention of subjective fatigue were partly related to the extent of changed proprioception. 2) There was no effect of acute muscle stretching on the proprioception. 3) The new method for testing muscle stretchability proved valid and reliable. A two-week stretching regimen increased the tolerance to stretch torque, but the range of motion remained unchanged. 4) Half of the nociceptive dorsal horn neurons that responded to close arterial injections of bradykinin were modulated by muscle stretching applied directly after the injections. Altogether, the results give credence to the hypothesis of an involvement of sensory information distortion due to repetitive low-intensity work exposure in the development of work-related neuromuscular disorders. Increased tolerance to stretch torque may be an important mechanism in explaining improvements following stretch treatment. The spinal interactions between innocuous stretch and nociceptive muscle afferent inputs indicate a possible mechanism involved in stretching-induced pain alleviation.

The purpose of this thesis is to explore the subject of industrial exoskeleton in accord-ance to the applicability of the technology preventing musculoskeletal disorders within the automotive industry. The modern technology of exoskeletons has a limited field of research and knowledge and is in need to be studied to provide organisations with proper findings for understanding the applicability of the technology. In the auto-motive industry musculoskeletal disorders (MSDs) is one of the most common disor-ders among employees and industries work constantly to decrease and prevent MSDs within their work environments. By conducting literature reviews, the status of exo-skeleton research and development concluded that academic research mostly focuses on technological development of exoskeletons, and not laboratory and/or field testing of currently available industrial exoskeletons. However, through database and website searches, twenty-four available industrial exoskeletons were identified which could be applicable within the automotive industry. Through literature and a case illustration, a number of potential causes for MSDs within the automotive industry were identified and a framework was developed in order to match appropriate available industrial ex-oskeleton to be used in potentially preventing common MSDs. The discussion of the thesis highlights the benefits and challenges of implementing an industrial exoskele-ton within an industry. Proper research on the currently available industrial exoskele-tons is lacking and creates questions of reliability for the technology. However, devel-opment of industrial exoskeletons have shown to focus on prevention of the most common causes of MSDs within industries in their design and development, making the applicability of industrial exoskeletons highly possible.

Made available in DSpace on 2016-06-02T20:18:14Z (GMT). No. of bitstreams: 1 3866.pdf: 6310029 bytes, checksum: 1dbae2c10aceb4a83b1489edc0b7fb1d (MD5) Previous issue date: 2011-10-24 / Universidade Federal de Minas Gerais / Electrical energy is an essential good that may affect people s life and the economy. Overhead line workers and construction electricians are the workers responsible for the availability of this good. To perform their occupational tasks these workers are exposed to fatal accidents and musculoskeletal overload. Although of high rates of accidents and musculoskeletal injuries among these workers, few studies evaluated the presence of risk factors in the occupational settings of line workers and electricians. In this sense, it is necessary to identify the risk factors in the electricians activities (Study 1), quantify the exposure using valid direct methods (Study 2, 3 and 5) and verify the importance of the found results for clinical applications (Study 4 and 5). Study 1 was developed to determine the prevalence of musculoskeletal symptoms among line workers and to identify the risk factors for musculoskeletal disorders. The results of this study showed postural overload and high prevalence of musculoskeletal symptoms at shoulders and neck. Based on these results, Study 2 was purposed to quantify the postural overload in the five main tasks performed by line workers. Loading and unloading the ladder on the vehicle support was deeply investigated by means of posture and force measurements in Study 3, due its higher frequency in line workers schedule. Postures and movements were recorded by four inclinometer sensors at a sampling rate of 20Hz. Inclinometer sensors were previously calibrated and them attached at workers head, upper back and right and left upper arms. Study 2 and 3 identified that line workers are exposed to shoulder and neck awkward postures during all evaluated tasks. However, both studies were performed in simulated settings. By this way, Study 4 was developed to verify if the postures recorded in the simulated conditions are representative of the posture recorded in occupational environment. The results of Study 4 showed that whether the tasks are possible to be reproduced in simulated conditions the postural overload is representative of occupational overload. Besides the representativeness, Study 5 focused the comparison between posture exposure among Brazilian and Norwegian electricians to verify whether the same job type evaluated by the same method under the same procedures would present the same overload disregard the culture differences. The results of this study would allow inferring about external validity of the recordings. According to the found results, Brazilian and Norwegian posture exposure is similar. The results of Study 5 also indicated the high postural overload that these workers are submitted. Therefore, the present thesis showed the need for ergonomic interventions to reduce biomechanical risk factors presented at electricians work activity and the representativeness of the found results to occupational environmental conditions and to other populations. / A disponibilidade de energia elétrica é um serviço básico que afeta diretamente a vida e a economia da população. Para a manutenção deste serviço, eletricistas das empresas de distribuição de energia e eletricistas de construção são expostos aos riscos de acidentes fatais e à alta sobrecarga musculoesquelética. Apesar do reconhecimento dos altos índices de acidentes e de lesões musculoesqueléticas nestes trabalhadores, poucos estudos que avaliam a exposição destes sujeitos aos fatores de risco presentes no ambiente ocupacional estão disponíveis na literatura. Neste sentido, é necessário conhecer os fatores de risco presentes na atividade ocupacional (Estudo 1), quantificá-los por medidas diretas válidas (Estudos 2, 3 e 5) e verificar a importância dos resultados encontrados para a prática clínica (Estudos 4 e 5). O Estudo 1 foi desenvolvido para determinar a prevalência de sintomas musculoesqueléticos em eletricistas de distribuição e identificar os fatores de risco para desordens musculoesqueléticas presentes nas atividades mais freqüentemente desenvolvidas por estes. Os resultados deste estudo mostraram alta prevalência de sintomas musculoesqueléticos em ombros e cervical associados à alta sobrecarga postural, identificada por observação. Com base nestes resultados foi proposto o Estudo 2 para quantificar a sobrecarga postural a que estes trabalhadores estão submetidos durante cinco das atividades freqüentemente realizadas. Maior detalhamento da atividade de remoção e reposição da escada foi realizado no Estudo 3, que envolveu, além do registro postural, a medida da força e esforço requeridos. As posturas e movimentos da cabeça, tronco superior, cervical e ombros direito e esquerdo foram registrados por inclinometria por meio de 4 transdutores previamente calibrados e fixos na cabeça, tronco superior e braços direito e esquerdo, respectivamente. Os Estudos 2 e 3 identificaram a exposição dos eletricistas de distribuição a posturas inadequadas para ombros e cervical nas atividades avaliadas. No entanto, como estes dois estudos foram realizados em ambiente simulado, foi realizado o Estudo 4, para verificar a representatividade destes resultados encontrados em ambiente simulado quando comparados ao registro realizado em ambiente ocupacional real. Os resultados do Estudo 4 mostraram que as atividades desenvolvidas em ambiente simulado podem apresentar a mesma sobrecarga postural do ambiente ocupacional desde que a atividade possa ser simulada. Além da representatividade, no Estudo 5 foi realizada a comparação da exposição postural entre eletricistas de construção Brasileiros e Noruegueses, para verificar se o mesmo tipo de trabalho, avaliado pelo mesmo instrumento a partir dos mesmos procedimentos, indicam a mesma exposição independente da cultura, o que permite inferir sobre a validade externa dos resultados encontrados. De acordo com os resultados encontrados, a exposição de eletricistas Brasileiros e Noruegueses é similar. Os resultados do Estudo 5 também indicam a alta sobrecarga postural a que os eletricistas de construção estão expostos. Portanto, a presente tese revelou a necessidade de intervenções ergonômicas para redução dos fatores de riscos biomecânicos presentes na atividade de eletricistas e a representatividade dos resultados encontrados para situações ocupacionais reais e para outras populações.

Made available in DSpace on 2016-06-02T20:19:21Z (GMT). No. of bitstreams: 1 DissTOS.pdf: 1026563 bytes, checksum: 3084e32eb13447dd885b2643417f39a5 (MD5) Previous issue date: 2005-02-22 / Financiadora de Estudos e Projetos / Work-related musculoskeletal disorders (WMSDs) constitutes a group of disturbs, with multifactorial origin, mainly promoted by workplace factors (physical, organizational and psychosocial). WMSDs cause high human, social and economic costs, which justifies effort to determine more efficient prevention strategies. However, for an effective prevention is necessary to establish the main risk factors, and create or aprimorate assessment tools. It was proposed a new tool for risk assessment Checklist for musculoskeletal risk assessment (RARME). The objective of this study was to evaluate the consistency of this checklist in relation to other physical load indicators: discomfort and exertion ratings, sick leave and Ergonomic Workplace Analysis. Thirty-one subjects took part in this study. They performed fifteen different tasks involving repetitive motion pattern and manual material handling. Checklist was applied by direct observation in the workplace. No relation between the results from checklist and the other physical load indicators was identified. Several factors might have contributed to the lack of consistency between indicators. Exposure variability, cognitive overload of the observer, bias in observation methods, and instruments for risk measurement are important factors to be considered when analyzing the present results. Thus, although it was not possible to check the protocol validity, relevant methodological aspects when using theses types of checklists were discussed. Besides this, an improved version of RARME protocol is presented. / As Lesões por Esforços Repetitivos/Distúrbios Osteomusculares Relacionados ao Trabalho (LER/DORT) constituem um grupo de distúrbios, de origem multifatorial, promovidos ou agravados por características do local de trabalho (físicas, organizacionais ou psicossociais). As LER/DORT causam alto custo humano, social e econômico, o que justifica esforços para determinar estratégias de prevenção mais eficazes. Porém, para uma prevenção efetiva é necessário que se identifique as principais causas destes distúrbios, além de se criar ou aprimorar ferramentas de avaliação dos riscos presentes no trabalho. Diante disto foi proposto o Roteiro para Avaliação de Riscos Músculo-Esqueléticos (RARME). O objetivo deste estudo foi avaliar a consistência deste Roteiro em relação a outros indicadores de sobrecarga física: escalas de desconforto e esforço, afastamento do trabalho e Análise Ergonômica do Local de Trabalho. Foram avaliados 31 indivíduos que realizavam 15 atividades diferentes com padrões de movimento repetitivos e manuseio de cargas. A aplicação do RARME foi feita por observação direta. Não foi identificada relação entre o RARME e os outros indicadores de sobrecarga física. Vários fatores podem ter contribuído para esta inconsistência. A variabilidade da exposição; sobrecarga cognitiva do observador e erros inerentes à observação; e características dos instrumentos usados para medir o risco são fatores importantes a serem considerados quando se analisam os presentes resultados. Portanto, embora não tenha sido possível checar a validade deste novo Roteiro, foi possível determinar uma série de considerações metodológicas importantes para o uso de protocolos de registro postural. Além disso, uma versão aprimorada do RARME foi proposta.