Localized muscular loads have in many cases replaced whole body loads in the current mechanized industry. In highly automated automobile industries, the prevalence of upper extremity musculoskeletal disorders is a matter of continuing concern. Overhead work has especially been noted for its association with shoulder related musculoskeletal disorders. Research aimed at determining causal relationships between overhead work and risk of injury has increasingly used localized muscle fatigue as an indirect or surrogate measure. In this study, localized muscle fatigue was used as a primary measure for studying the effects of workload level while performing overhead work. Subjective (ratings of perceived discomfort) measures of fatigue were collected and their predictive potential was investigated. Effect of personality type was also examined to account for any inter-individual differences in fatigue perception. While researchers have studied specific task conditions in controlled environments, the specific relationship between various risk factors and underlying injury mechanisms is largely unknown. Two main problems faced by researchers are limited resources and the large scope of potential ergonomic analyses. This study attempted to circumvent some of these limitations by examining the time-course of fatigue and the predictive potential of subjective measures. The feasibility of using shorter experimental durations to make deductions for a 2-hour work period was explored. Reductions in experimental duration means decreased experimental time, expenses and resources. Thus, in turn, the researcher can utilize available resources to study more factors and a more general scenario. Specifically, subjective measures of shoulder fatigue were used to determine the possibility of reducing experimental duration for an intermittent overhead task. A laboratory-simulated intermittent overhead task was designed based on observations made at an automotive assembly unit. For this study, two treatment conditions were tested consisting of different combinations of two tool masses and two duty cycles. The choice of the treatment conditions was made to simulate different task difficulty levels of occupational tasks and their effects on shoulder fatigue. Each experiment was conducted for 2 hours (a common duration in industries with job rotation) for these selected treatment conditions. Subjective measures of fatigue were collected to assess shoulder fatigue and relative acceptability of the overhead work. Any observed trends in the subjective fatigue measure were determined and tested using statistical and mathematical models to determine how best to represent their salient characteristics. Derived qualitative and quantitative measures were also used to estimate the maximal acceptable task durations using certain formalized assessment techniques. Results of this research suggest possible reductions in the experimental duration. Short (8 to 26 minute) trials were found to be sufficient to predict performance measures for 2 hours. Results also indicated a strong influence of task difficulty level on the predictive performance of subjective measures though personality type did not show very consistent trends. Various unique analysis techniques used to look at the psychophysical data may prove useful for further investigation into predictive verification. A generalized mathematical model, a type of approach, was also developed to represent changes in the psychophysical measures over time. This research can find both industrial and research applications where resources are constrained and using psychophysical measures is feasible. In the following report, details on this work are presented, including a description of the factors that inspired this study, an outline of the relevant literature, methodology, results and their implications. / Master of Science

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2018-12-17T11:52:56Z No. of bitstreams: 1 Maria Ivone Fortunato Laraia.pdf: 1689216 bytes, checksum: bb1aff1784125d849eedf26f1a503a17 (MD5) / Made available in DSpace on 2018-12-17T11:52:56Z (GMT). No. of bitstreams: 1 Maria Ivone Fortunato Laraia.pdf: 1689216 bytes, checksum: bb1aff1784125d849eedf26f1a503a17 (MD5) Previous issue date: 2018-12-03 / The intermittent labor contract, provided for in the text of article 452-A of the Consolidation of Labor Laws, a mechanism added by labor reform (Law 13467/17), is a contract in which the rendering of service, with subordination, is not continuous, with periods of actual work and inactivity, and can be determined by hour, day or month of work and without a fixed journey. It was conceived to be one of the solutions found for the serious Brazilian economic crisis, since it aims to create jobs, modernize labor laws and increase the competitiveness of Brazilian companies, facing the demands of contemporary capitalism. The intermittent contract, as it was instituted, breaks with the logic of the standard employment bond and contributes to the precariousness of the employment relations, since it allows the use of labor in a discontinuous way; authorizes the payment of salaries lower than the minimum constitutionally guaranteed; violates the principles of human dignity and the social value of work, improves the social status of the worker and offends the right to paid annual leave, at least one third more than the normal salary of the worker, rendering building a free, fair and supportive society, with the eradication of poverty and the reduction of social inequalities, thus failing to promote the welfare of all. This paper presents a proposal for a bill, inspired by Portuguese and Italian legislation, in order to enable the intermittent employee to carry out fundamental social rights, especially human dignity / O contrato de trabalho intermitente, previsto no texto do artigo 452-A da Consolidação das Leis do Trabalho, dispositivo acrescido pela reforma trabalhista (Lei 13.467/2017), é um contrato em que a prestação de serviço, com subordinação, não é contínua, havendo períodos de efetivo trabalho e de inatividade, podendo ser determinado por hora, dia ou mês de trabalho e sem uma jornada fixa. Foi concebido para ser uma das soluções encontradas para a grave crise econômica brasileira, pois objetiva a criação de empregos, modernização das leis trabalhistas e o aumento da competitividade das empresas brasileiras, diante das exigências do capitalismo contemporâneo. O contrato intermitente, da forma como foi instituído, rompe com a lógica do vínculo de emprego padrão e contribui para a precarização das relações de emprego, pois permite a utilização da mão de obra de forma descontínua; autoriza o pagamento de salários inferiores ao mínimo constitucionalmente assegurado; viola os princípios da dignidade humana e do valor social do trabalho, da melhoria da condição social do trabalhador e ofende o direito do gozo de férias anuais remuneradas, com, pelo menos, um terço a mais do que o salário normal do trabalhador, inviabilizando a construção de uma sociedade livre, justa e solidária, com erradicação da pobreza e redução das desigualdades sociais, deixando, assim, de promover obem de todos. Neste trabalho, apresenta-se uma proposta de projeto de lei, inspirada nalegislação portuguesa e na italiana, com a finalidade de possibilitar ao empregado intermitente a efetivação dos direitos fundamentais sociais, especialmente a dignidade humana