«FICHA TÉCNICA Título Segurança e Higiene Ocupacionais - SHO 2012 - Livro de Resumos Autores/Editores Arezes, P., Baptista, J.S., Barroso, M.P., ...»
Responsabilidade social das empresas: uma nova estratégia da UE para o período de 2011-2014:
- Reconhecer e reforçar o impacto social das empresas;
- Melhorar os níveis de confiança nas actividades empresariais;
- Focalizar no respeito pelos Instrumentos internacionais em matéria de RSE acordados;
- Promover a mudança de padrões de mercado promovendo, o consumo responsável, as compras públicas responsáveis e o investimento responsável;
- Promover a divulgação de informações das empresas em matéria social e ambiental;
- Reforçar a RSE nas relações com outros países e regiões do mundo;
- Aprofundar a integração da RSE na educação e investigação;
- Sublinhar a importância de políticas nacionais e regionais de SER.
3. REFERÊNCIAS European Commission, 2010, Corporate Social Responsibility – National Public Policies in the European Union, December, 2010.
Comissão Europeia, Responsabilidade social das empresas: uma nova estratégia da UE para o período de 2011-2014, COM (2011) 681 final, de 25 de Outubro.
ISO, International Standard ISO 26000 - Guidance on social responsibility, ISO, 2010.
Oliveira, A., 2009, A Responsabilidade Social das Empresas em Contexto de PME – Oportunidades e Responsabilidade. Como Apoiar Mais as Pequenas Empresas a Integrar as Dimensões Socais e Ambientais nas suas Actividades, Cadernos Sociedade e Trabalho XI, GEP, MTSS, 2009.
Oliveira, A., Cordovil, I., Severino, O., (co-autor), 2009, A Responsabilidade Social das Empresas Diz Respeito a Todos Nós, Cadernos Sociedade e Trabalho XI, GEP, MTSS, 2009.
Psychophysical study of manual loads transportation - a comparative study between students and seasoned workers Oliveira, Elsa a, Rodrigues Matilde A. a, Silva Manuela V. a, Azevedo, Ruib and Carvalho, Albertoc a Porto Polytechnic Institute, School of Allied Health Technology, Research Center on Environment and Health,Vila Nova de Gaia, email: email@example.com; firstname.lastname@example.org; email@example.com b Technical support centre for occupational safety, ISMAI, Castêlo da Maia, email: firstname.lastname@example.org c CIDESD/CIDAF – Centro de Investigação em Desporto Saúde e Desenvolvimento, ISMAI, Castêlo da Maia
1. INTRODUCTION Musculoskeletal Disorders (MSDs) have become a priority in recent years at the occupational level, due to its considerable number (Pheasant, 2003). Among the factors that potentiate the development of MSDs, the Manual Material Handling (MMH) is one of the most important. The MMH is recognized as a major source of injury in industrial work (DGS, 2008).
In order to reduce the risk of injury due to MMH tasks, many researches have used different approaches to develop MMH guidelines. The biomechanical, physiological and psychophysical are the three most common approaches applied (Nussbaum & Lang, 2005). Among these approaches, the psychophysics can be highlighted. The psychophysical approach aims at designing "acceptable" tasks for most workers that execute them (Dempsey, 1998). This approach uses criteria such as Rate of Perceived Exertion (RPE), Maximum Acceptable Forces, Frequencies and Maximum Acceptable Weights (MAW) (Nussbaum & Lang, 2005; Wu & Chen, 2001; Yoon & Smith, 1998 Mital et al., 1997; Ciriello, 1990).
Implicitly or explicitly, the criteria are based on the assumption that individuals can detect the physiological and biomechanical stimulations in order to provide a subjective evaluation of physical exertion (Nussbaum e Lang, 2005).
Therefore, the ratings are based on the perception that the workers have of the physical effort and its results are considered subjective (Asfour, 1980).
The psychophysical approach has been the source of the so-called psychophysical criteria, which has served as a basis for risk reduction measures, together with biomechanical, physiological and, sometimes, epidemiological criteria, as well as some methodologies for risk assessment of MMH tasks, as the NIOSH’91 equation (Waters et al., 1994) and the Mital et al. (1997) methodology.
Given the importance of these criteria, it is essential that these studies be carried out as accurately as possible. However, these studies are associated with some limitations, as the selected sample. The analysis of the work of Asfour (1980) revealed that several authors conducted studies in the 70s for MMH based on the perception of students, i.e., individuals who are not familiarized/experienced with the tasks. Nevertheless, other authors conducted studies in individuals experienced in MMH tasks (see for example, Snook & Ciriello, 1991; Ciriello, 2001; Wu & Chen, 2001; Ciriello, 2005).
Thus, a tendency for changing the samples under study is becoming more frequent, opting for the use of experienced workers, there are still authors who currently continue to use students as a basis for their studies (Nussbaum & Lang, 2005). Therefore, it is important to consider whether the use of students as a sample may have influence on the results.
Bearing this in mind, this work intends to analyze the influence of the sample in determining the MAW in tasks of manual transportation of loads.
2. METHODOLOGY Using a psychophysical approach, 20 individuals (10 students and 10 workers) proceeded to determine the MAW and the RPE. The participants’ task was to carry a box for 13 minutes, travelling six meters in the designed posture to isolate three major joints: shoulder, elbow and lower trunk (Nussbaum & Lang, 2005). This is the base posture, and the worker carried the box next to the body, i.e., elbows remained in line with the trunk and the trunk was erect (Nussbaum & Lang, 2005). Every 6 meters, the individuals placed the box on the surface of support, where they could add or remove weight.
The box carried by the individuals had a false bottom, in which 5 kg were hidden. Initially, the individuals were asked to select the weight that they could carry for 1 hour of work. For that, it was asked to adjust the suggested weight, 17.25 kg, to what they found suitable for the conditions proposed, which would be considered the Initial Weight (IW). Throughout the journey, subjects were encouraged to make adjustments to the IW (adding or removing weight to get to the MAW for the period of 1 hour without pain, fatigue or tiredness (Ciriello, 2005). During this journey, the subjects adjusted the weight whenever necessary. The weight obtained at the end of 13 minutes was considered the MAW for 1 hour of work, which is considered representative of 8 hours of intermittent work (Yoon e Smith, 1998).
Two types of weights were used: 1kg and 1.25kg. These had different volumes, so that individuals would not be aware of their real weight.
Once the task was completed, MAW values were recorded in the respective field form. Later, an individual questionnaire was applied to assess the RPE and pain/discomfort. In the end, a strength test was applied to each individual, based on the performance of crunches and push-ups, in order to evaluate the strength in the abdominal region and upper limbs, respectively. The former were performed during a period of 2 minutes, while the latter were performed for the maximum number the individuals could withstand.
3. RESULTS AND DISCUSSION
3.1. Anthropometric characteristics of the sample The students presented a year average of 23.3, a height average of 176.4cm and a weight average of 69.3kg. The workers showed a year average of 28.1, a height average of 178.3cm and a weight average of 73.7kg.
3.2. Strength test The students presented, on average, more crunches and push-ups, 46.7 and 24.7, respectively. Workers presented an average of 33.7 crunches and 21.1 push-ups. Thus, students showed a higher strength than workers. Statistically significant differences were observed in relation to abdominal strength (p0.05, Mann-Whitney test). The results can be explained by the fact that some students practice physical exercise and are more suitable for these activities, performing them with greater skill, as individuals engaged in exercises like crunches and push-ups gain more strength and resistance in the upper abdominal region, in comparison to individuals who do not practice this type of exercise (Jacinto, 2001).
3.3. Maximum Acceptable Weight (MAW) for manual load carrying The results obtained for the experiment conditions, in which individuals have walked 6m during 13minutes, are showed in Table 1. The average MAW obtained by students was 11.6kg and for the workers 10.8kg. Thus, it was observed that the students carried, in average, 0.8kg more than the workers, however, does not exist significant differences between groups (p0.05, Mann-Whitney test). Moreover, it was expected that the stronger subjects had carried loads with more weight, however there was no relationship between the MAW and the strength in both groups (R20.252). Also the IW was supposed to have influence in the MAW. Only on students there was a relationship between IW and MAW (R2=0.859). Thus, on the students sample, the higher the initial weight, the greater the MAW. These results may be related to the fact that workers have a greater experience in load carrying, and therefore may have a greater perception of risk (Arezes & Miguel, 2008), in particular, regarding the need for continuity of effort, increased the perception of pain or discomfort.
Although studies that compare the MAW with different samples were not been found, we found similar studies where in some cases they use workers for the MAW determination and other students. For example, Wu & Chen (2001) and Cheng & Lee (2006) have used the same methodology for the MAW determination. When the sample was composed by students (Wu & Chen, 2001) weights were higher than when workers were used (Cheng & Lee, 2006), in the same way than in this study. Therefore, seems to exist an influence of the sample in the MAW determination.
3.4. Rate of Perceived Exertion (RPE) for manual load carrying Through the results obtained, which are presented in Table 2, it appears that, in average, students assign RPE values higher than workers. From the results presented, three areas may be highlighted for obtaining the highest values: arms (14.5 for students and 12.3 for workers), back (13.1 for students and 10.1 for workers) and whole body (12.3 for students and 10.2 for workers). However, among these, the region of the arms is the one with higher marks for both students (14.5), and workers (12.3). These results are in line with those obtained by Wu & Chen (2001) for students and Cheng & Lee (2006) for workers. These results may be associated with the need to maintain the required posture and thus require further efforts in this region. There were no significant differences between groups in relation to the RPE (p0.05, MannWhitney test), and there was no relationship between the MAW and the RPE.
3.5. Classification of pain/discomfort The European Agency for Safety and Health at Work describes the back pain as one of the major health problems related to work (23.8%) in the European Union (EU-OSHA, 2007). Thus, it was expected that the individuals would perceive greater pain/discomfort in the lumbar region. In this study, the results highlighted three areas of the body: elbows, wrists and lower back. Students attributed, respectively, 1.90, 1.10 and 1.60, and workers 1.60, 0.80 and 0.80. Among the three, the region of the elbow was the one with a higher rate of pain/discomfort in both groups during the transportation of the load. This may be associated with the obligation to maintain the position of the forearm perpendicular to the body, as requested.
4. CONCLUSIONS This study demonstrated that the MAW was depending on the sample groups (students and workers), having been obtained MAW higher for students (11.6kg) than for workers (10.8Kg). However, does not exist significant differences between groups. In addition, it was found that, for students, the MAW depends on the selected IW. Thus, it is expected that the workers' experience and their perception of the work reality and their physical limitations may be a determining factor in the MAW. So, samples comprised by students may affect the results, being that these groups of samples should be used with caution. Therefore, whenever possible, sample groups should comprise workers, the studies must be adapted to the work conditions and include other factors as years of experience and training.
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Arezes, P.M. e Miguel, A.S. (2008). Risk perception and safety behavior: A study in an occupational environment. Safety Science, 46, 900-907.
Cheng, T. S. e Lee, T.H. (2006). Maximum acceptable weight of manual load carriage for young Taiwanese males. Industrial Health, 44, 200-206.
Ciriello, V.M. (2005). The effects of box size, vertical distance, and height on lowering tasks for female industrial workers.
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Ciriello, V.M., Snook, S.H., Buck, A.C. e Wilkinson, P.L. (1990). The effects of task duration on psychophysically-determined maximum acceptable weights and forces. Ergonomics, 33, 187-200.
Dempsey, G. P. (1998). A critical review of biomechanical, epidemiological, physiological and psychophysical criteria for designing manual materials handling tasks. Ergonomics, 41, 73-88.
DGS (2008). Lesões Músculo- esqueléticas Relacionadas com o Trabalho- Guia de Orientação para a Prevenção. Lisboa. DirecçãoGeral de Saúde. (in portuguese) Accessed:
EU-OSHA (2007). FACTS: Perigos e riscos associados à movimentação manual de cargas no local de trabalho. Agência Europeia para
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http://osha.europa.eu/pt/publications/factsheets/73 Jacinto G. (2001). Efeitos de um programa de treino de força em contexto escolar. Um estudo em crianças e adolescentes dos 12 aos 14 anos da cidade de Maputo. Tese de mestrado em ciências do desporto. Faculdade de Ciências do Desporto e de Educação Física Universidade do Porto, pp.101. (in portuguese).