Iranian Journal of Ergonomics
Year:2019 | Volume:2 | Issue:1 |Papers Count:12

Background and Objectives: The use of new technologies, particularly mobile phones, is drastically growing on a daily basis. The usability of mobile phones can be determined for different age groups in order to reach a balanced development plan with respect to this technology. The present study aimed to investigate and compare the usability of touch-screen and button cell phones among Iranian elderly users, with respect to objective performance and perceived usability. Methods: In this cross-sectional study, 20 elders (50% female) with an average age of were selected by simple random sampling method to measure the usability of touch-screen and button cell phones. In order to assess the objective performance of how elders work with cell phones, tests were conducted including items like typing speed, number of typing errors, taking photo, creating new contacts, and sending text messages. Perceived usability was obtained using a questionnaire of cell phone usability. Furthermore, muscle pressure and mental work load during cell phone use were evaluated by Borg CR10 and NASA-TLX questionnaires, respectively. Data were analyzed conducting statistical analysis tests of T-test and Mann-Whitney by SPSS24 software. Results: Results revealed that the average typing speed and typing errors in touch-screen cell phones are larger than that in button cell phones. Moreover, the average of perceived usability in touch-screen cell phones (5. 8) is higher than that in button cell phones (4. 3). Pearson correlation coefficient showed an inverse relationship (-0. 3) between perceived usability and mental work load obtained in both types of the cell phones. Findings showed that the maximum perceived muscle pressure when working with a cell phone is felt in the neck area. Conclusion: According to the obtained results, touch-screen cellphones are suggested for those elders who type more and button cell phones are recommended for those who use the cell phone menu more frequently, namely taking photo, calling, internet, and so forth.

Background and Objectives: Quality of work life is one of the most important factors in promotion of teachers and having them continue their jobs. This study aimed at designing and evaluating a questionnaire for teachers’ work life quality. Methods: In this research, a sequential exploratory approach (instrument editing model) was used and in the qualitative stage, a semi-structured interview method was used to determine the quality of life of teachers. In the qualitative stage, indices of work life quality were identified using semi-structured interviews with 12 teachers (9 men and 3 women) of Karaj city (2014-2015 educational year) selected through purposive sampling method. The qualitative data was analyzed using Straus and Corbin method. Subsequently, a questionnaire of teachers’ working life quality was constructed based on these indices and was validiated in the quantitative stage. Results: Content validity was confirmed by five experts using content validity index. A sample of 760 (387women) teachers selected through multistage cluster sampling were handed out two questionnaires including a researcher-made questionnaire of teachers quality of working life and Walton (1973) quality of work life questionnaire. Construct validity of the research-made questionnaire was examined using exploratory factor analysis. Eight factors were extracted and confirmed through confirmatory factor analysis. Fit indices of model indicate compliance. Convergent validity was confirmed by its correlation with the quality of work life questionnaire (P<0. 01). Reliability was confirmed by calculating Cronbach’ s alpha coefficient (0/74-0/88). Conclusion: The results of the study indicated that the researcher-made questionnaire with regard to its design in the job context of Iranian teachers, with 54 items, is an appropriate tool for assessing the quality of their working life.

Background and Objectives: These days, due to increasing of old people’ s population, elderly is a world widely issue. According to World Health Organization (WHO) people older than 60 years old are called elderly. Becoming old leads to decline in physical ability and increase in physical limitations and therefore there is a need for matching the environment with elderly users. The aim of this study is to develop and valid of check lists for screening the environment risk factor and assessing of elderly functional ability for environment and tools designing. Methods: Present study is an analytical and descriptive study, which was performed in 20 houses for old people in Lar city. Data collection was done on existing articles and checklists, and also interview and observation with elderly. Existing checklist was evaluated in validity and reliability with high acceptable level. Results: Based on findings of this study, height of mirror of wash-stand, height of wash-stand, dimension of yard and doorway was considered in ergonomics risk factors checklist. Items like opening door personally was involved in Functional Ability checklist. Validity score was lower than 0. 78. Conclusion: According to findings, it’ s necessary to consider elderly limitations and ability in designing environment and tools in order to resolve their problems and increase their quality of life.

Background and Objectives: Considering that musculoskeletal disorders and occupational stress are one of the most important reasons for disability, physical and mental problems in the staff, the study of their causes is of great importance. Therefore, this study was conducted to investigate the relationship between ergonomic risk level and job stress in employees of a food production plant. Methods: This was a descriptive-analytic research. It was carried out for a sample of 200 employees in the production and packaging of a food production plant in 2018. The QEC method was used to determine the ergonomic risk level and the OSPU questionnaire was used to measure occupational stress. Descriptive and inferential statistics (T and F tests) were used to analyze the data. Results: The findings showed that the level of ergonomic risk in the neck, shoulders and wrists is in the unfavorable situation. Workstations will need to be repaired in the near future. There is a significant relationship between the level of ergonomic risk and the demographic variables of gender and education with job stress. Conclusion: Unfavorable ergonomic status of workstations in the food factory has increased the worker’ s stress in the manufacturing and packaging sectors. Therefore, proper design of workstations and consideration of ergonomic principles are effective in improving the physical and mental health of employees.

Background and Objectives: The progress and rebound of organizations depends on their productivity. Many factors affect the organization’ s productivity; identifying these factors the organization’ s deterrence can be prevented. In this study, the relationship between job burnout and employee productivity has been investigated. Methods: This research is applied and its statistical population is 1265 people in Shariati and Kharazi hospitals. 294 of these employees were selected by Convenience sampling method considering the Cochran formula. Data was collected using the Maslach Burnout Standard Questionnaire and Hersey and Goldsmith Human Resources productivity Standard Questionnaire. Pearson correlation test and SPSS18 was used to analyze the data. Results: The results of data analysis showed that burnout, emotional exhaustion, depersonalization and reduced personal accomplishment with-0. 82,-0. 86,-0. 83 and-0. 85 correlation values, respectively, have a reverse and meaningful relationship with employee productivity of Shariati and kharazmi Hospitals employees. Conclusion: Since the results showed that burnout and its dimensions have a significant relationship with productivity of Shariati and Kharazmi Hospitals in Isfahan, it is necessary for organizations to apply measures to reduce the feeling of burnout in the staff. The results of this study are consistent with the results of other studies. At the end of the study, were presented several research proposals based on the results of the study.

Background and Objectives: Studies have shown the effect of smoking on mental and cognitive performance of the individuals who need to concentrate on their work. The present study aimed to investigate the effect of smoking on cognitive performance of the automotive industry workers. Methods: In this case-control study conducted in 2018, 280 automotive industry workers were selected through the simple random sampling and then assigned to two groups of smokers (100 cases) and non-smokers (180 controls). All the subjects were selected from the environments with the sound levels of 82 to 88 dB. The workers’ cognitive performance was also tested using the CPT, Stroop and Tower of London tests. Results: The mean age of the case group was 36/02 (3/7) and that of the control group was 36/25 (3/65) years. The results showed that the scores of the TOL test in the case group (smokers) were lower than those of the non-smokers (OR=0/903, P<0. 01), and other items of the TOL test had no significant relationship with the individuals’ smoking status (P>0/05). The Stroop and continuous performance tests also had a significant relationship with the individuals’ smoking status in terms of the number of correct responses and the response time as well as interference (P<0. 01). Other items had no relationship with the individuals’ smoking status (P>0/05). Conclusion: The results of this study showed that the use of cigarettes and nicotine substances significantly decreased the workers’ mental and intellectual performance, and smokers were more likely to suffer from concentration interference, low brain processing speed in decision-making, and low precision at work, compared to non-smokers.

Background and Objectives: Noise pollution is one of the most harmful physical factors in working environments in developed and developing countries, which has significant impacts on the workers’ quality of life. The aim of this study was to investigate mental and physiological effects of chronic exposure to noise. Methods: This is a cross-sectional study carried out randomly in 2018 on 250 workers in the automotive Industry. To measure the subjects’ aggression and annoyance levels, the Buss and Perry’ s Aggression Questionnaire was used as well as an annoyance questionnaire. In this study, blood pressure measurement was also done using ALPK2 mercuric pressure gauge. Results: The results showed that there was a significant difference in the systolic and diastolic blood pressure and noise annoyance in the groups with a lower-than-85 and higher-than-85 dB sound pressure levels (P<0. 001). Besides, the results of multivariate regression showed that the annoyance level and sound pressure level had a significant relationship with the workers’ blood pressure (P<0. 01). Also, there was a significant correlation between aggression components and sound pressure level (P<0. 01). Conclusion: The results of this study clearly showed that chronic exposure to noise in work environments was associated with psychological and physiological changes, such as increased blood pressure and aggression levels. Hence, implementation of preventive programs can help reduce the incidence of the psychological and physiological disorders.

Background and Objectives: One of the most important causes of industrial incidents, of which 90% is related to human factors, is to refuse to accept errors because of fear of blaming and concealing them. In the present study, the relationship between just culture and safety culture was investigated in one of the industrial sections of Tehran. Methods: The research was descriptive-analytic and conducted as a cross-sectional study. Out of 320 a sample of 181 staff who worked at the operational and administrative sections were selected in an accessible manner. The research instruments consisted of questionnaires of personal and occupational information, just culture and safety culture. Data was analyzed using, Pearson correlation coefficient and multivariate regression by SPSS22 software. Results: The relationship between different dimensions of safety culture and just culture is 0. 84 (P<0. 001). The power prediction of safety culture is based on different dimensions of the just culture 0. 70 (P<0. 05). Between different dimensions of safety culture, the level of information exchange, education and management commitment are most closely related to mean of just culture. Also, the level of information exchange is the highest and safety priority shows the least link with the just culture. Therefore, the exchange of information can lead to a continuous improvement of the just culture. Conclusion: Evaluating the just culture, the safety culture of the employees of the organization can be predicted with a high level of certainty, which shows the direct relationship between the just culture and the safety culture. So, increasing the just culture directly contributes to the development of the safety culture.