Iranian Journal of Ergonomics
Year:2019 | Volume:7 | Issue:2 |Papers Count:11

Background and Objectives: One of the most effective methods for managing ergonomic risk factors in the workplace is to involve employees in identifying and assessing ergonomic risk factors and ultimately designing and implementing interventions by themselves. Therefore, this study aimed to implement a participatory ergonomic program, focusing on the transfer of ergonomic knowledge to employees, and to examine the effects of interventions on the macroeconomic indexes. Methods: This semi-experimental interventional study was carried out in cooperation with all staff of one of the medical diagnostic laboratories in Isfahan (11 people) in 2017. A participatory ergonomic program was implemented based on the Occupational Health Clinics for Ontario Workers Inc. (OHCOW) Guide. Then, the differences in the level of macro ergonomic elements such as job satisfaction and increase in motivating potential score of employees were studied before and after the interventions resulting from participatory ergonomic program (OHCOW) in this work environment. The data was analyzed using SPSS 23. Results: Job satisfaction before and after ergonomic interventions had no significant difference (a relative increase), but in one of the scales, namely organizational climate, there was a significant change (P=0. 016). Also, the motivating potential score of employees after the intervention was significantly higher than before (P=0. 013). Conclusion: In this study, participatory ergonomics were used to improve some aspects of macro ergonomic elements. Based on the results of this study, participatory ergonomics can increase some job satisfaction scores and motivating potential score of employees. Finally, it is suggested that allocate a longer duration for intervention utilization.

Background and Objectives: In recent years, due to the rapid growth of metropolitan cities and the shortage of urban public transport means, including urban bus transportation, many people are forced to travel in a standing position when using these vehicles. This situation may cause pain and discomfort and non-collision injuries for passengers. The purpose of this study was ergonomic assessment of the sit-standing seat in passengers standing on urban buses. Methods: To do this study, 8 young people with a mean age of 25. 25± 2. 12 years were enrolled. For evaluation and assessing the effect of sit-standing seat two methods of surface Electromyography (sEMG) and Borg scale scores were applied in Fall 2018. The data was analyzed using SPSS 24. Results: In all body parts, except for the hip, the mean scoring of Borg’ s scale for perceived discomfort in sit-standing position was less than standing position. Also, the amount of contractile activity of the leg muscles in sit-standing position was significantly lower than the standing position (P<0. 05). Conclusion: Considering the results obtained from the Borg scale scores and the contraction activity of the leg muscles as a result of the use of the mentioned seat, which led to a reduction in the level of discomfort and the leg muscles contraction, it is recommended to apply the sit-stand seat instead of being in a standing position.

Background and Objectives: Exposure limit of employees with ergonomic risk factors should be managed based on domestic and international laws and regulations. Manual tasks are tasks due to which a person is required to use part of the body to lift, lower, push, pull, carry and hold the material. The purpose of this study was to introduce ergonomics with the implementation of the PErforM Participatory ergonomics program. Methods: The present study was carried out on all employees working in the Reactor Charging Unit of a resin company during the year 2017. The participatory ergonomics for manual tasks (PErforM) Method was used to manage ergonomic risks due to manual tasks. After holding several training sessions, ergonomic risks have been identified and evaluated using the ManTRA (Manual Tasks Risk Assessment) tool and also by staff. Then interventions suggested by the staff using the DotMocracy tool were eventually implemented. Also, the proposed interventions were simulated before implementation, in order to assess interventions’ implementation. Results: The tasks of pushing pallets containing 800 kg bags and machines with 25 kg bags were identified as risky manual tasks using ManTRA. After the interventions using participatory ergonomics, the intensity of repetitive tasks and force in the areas of the hands, shoulders and lower back were reduced. Conclusion: Generally, the PErforM has a high capacity to modify employee’ s exposure to ergonomic risk factors, as well as to discover effective, simple, and effective control strategies. However, achieving this goal requires the promotion of ergonomic knowledge and management commitment.

Background and Objectives: There are various models of socket wrench in the market varying in the length and diameter of handle and weight. Each of these features alone can modify the force applied by the hand and affect how comfortable the user is. The purpose of this study was to investigate the relationship between dimensional properties and weight of several models of socket wrench with their usability index score. Methods: 58 male technicians from maintenance units of Shahid Beheshti University of Medical Sciences performed the task of opening 12 bolts with 8 N/m of torque using 6 models of socket wrench with different physical properties. The sample size was selected based on proposed figures for usability studies. The System Usability Index (SUS) validated questionnaire was used to determine the usability score of each model after the experiment. The study was conducted in 2017. SPSS 21 was used for data analysis. Results: The results showed that there was a significant relationship between usability index score and dimensional properties and weight of wrenches (P<0. 001). Wrench models with longer handle and diameter size close to optimum range of diameter of hand tools for male users had a higher usability score, and participants reported a better test experience with these models. Conclusion: Using the System Usability Index (SUS Questionnaire) to measure the quality of human-centered design of hand tools is a good way to evaluate and select the hand tools that are widely used by technical staff. The results of this study are valid for short-term applications of wrenches. However, for long time activities, epidemiological and physiological evidences such as EMG should also be used.

Background and Objectives: Design of work environment is one of the factors that can affect performance and efficiency of employees. Human’ s productivity has different dimensions that may be affected by environmental factors and internal factors such as demographic characteristics. Therefore, this study was designed to investigate the relationship between environmental and demographic factors with productivity of employees of Azad University of Shiraz. Methods: In this cross-sectional study, out of 360 (all of the employees of Islamic Azad University, Shiraz branch)186 subjects were selected as a sample through convenience sampling. The data collection tools were demographic information questionnaire, Physical Work Environment questionnaire and Hersey-Goldsmith’ s productivity questionnaire. Pearson correlation coefficient was used to measure the relationship between quantitative variables with productivity separately. Multiple linear regression analysis was used to examine the relationship between demographic and environmental variables. Results: The results showed that there was a significant relationship between the factors of work environment design (furniture, noise, temperature, lighting and spatial arrangements). Also, there was a significant relationship between the levels of education with productivity score, so that people with a PhD level had a higher level of productivity than the participants with lower education. Also, the simultaneous relationship of demographic and environmental factors with productivity was significant for spatial arrangements. Conclusion: The proper design of the work environment is related to employees’ productivity of Islamic Azad University of Shiraz. This can be affected by the demographic characteristics of individuals. However, the simultaneous effect of both factors with productivity showed that spatial arrangements has a considerable effects on productivity.

Background and Objectives: Mental fatigue is a condition triggered by prolonged cognitive activity. Mental fatigue causes brain over-activity. This is a condition where the brain cells become exhausted, hampering person productivity, and overall cognitive function. The aim of this study was to assess students’ mental fatigue using brain indices. Methods: The present descriptive-analytic study has been conducted on 20 students of the Faculty of Health mean age (SD) of 24. 40 (3. 73) years old in Ahwaz University of Medical Sciences (2019). To assess the performance of the participants, they were asked to study a text with spelling errors and correct those errors. This activity was performed in five stages, each lasting 15 min and EEG was recorded at all stages, and at each stage, the visual analog scale was completed by participants. Data analysis was done by SPSS 24. Results: The results showed that the activity of alpha, beta, and theta signals in the first 15 minutes was 0. 89± 0. 30, 0. 70± 0. 33, and 1. 19± 0. 36, and the last 15 minutes, 0. 63± 0. 34, 0. 55± 0. 26, and 1. 03± 0. 34 respectively. Reducing the activity of the signals indicated there has been an increase in the amount of mental fatigue in individuals. Also, using visual analog scale, the individuals have acknowledged that they have experienced symptoms of mental fatigue. Finally, there was no significant relationship between students’ EEG and visual analog scale. Conclusion: The results showed that alpha, beta and theta indices could be suitable indicators for evaluating mental fatigue. Also, mental fatigue can be one of the factors that affect the accuracy and performance of individuals, so that it can reduce their attention and efficiency.

Background and Objectives: The ethic-based culture is the predictor of ethical behavior and organizational citizenship behavior. Ethical culture enhances our awareness of our activities and can also increase our awareness of our bilateral commitments to the organization and therefore focus on what is important in an organizational setting. The present research aimed at investigating the relationship between the ethical culture with a tendency to ethical behavior and organizational citizenship behavior by examining the mediating role of the person’ s organization in the staff of Urmia University. Methods: This descriptive correlation study is a structural equation modeling model. The statistical population of this study consisted of all 503 high school graduates of Urmia University in 2018. Based on the stratified random sampling method, 217 individuals were selected. Standard questionnaires were used to collect information. Data analysis was performed using descriptive indexes and structural equation modeling method. Results: Based on the results there is a positive and significant relationship between ethical culture with ethical behavior and organizational citizenship behavior. Also, the direct and significant impact of ethical culture on the individual-organizational adaptability was confirmed. The results also showed that the individual-organizational adaptability has a positive and significant relationship with ethical and organizational citizenship behaviors. In addition, the role of mediation of this variable (individual-organizational adaptability) in the relation between the ethical culture with two other variables (ethical and organizational citizenship behaviors) was also confirmed based on the findings of the research. Conclusion: Based on the findings, it can be concluded that ethical culture directly promotes personal-organizational fit. In addition, confirming the mediating role of the individual-organization fit ethical culture has an indirect, positive and significant effect on ethical behavior and organizational citizenship behavior.

Background and Objectives: Given the increasing prevalence of smart phone usage, it can be considered as an important and significant issue in all aspects of human life. Therefore, the purpose of this study was to study the effect of duration of smartphone use on head and shoulder posture of young adults aged 20-35 years. Methods: The statistical population of this study was young people aged 20 to 35 with smart phones who were resident of Kish Island in 2018. A sample of 50 people (25 men and 25 women) were selected voluntarily and purposefully. Lowuser and High-user groups were identified by completing the form of addiction to smart cell phone, in assessing the status of upper limb, the shoulder position was measured by Scapular index and head position was measured by photogrammetric method technique and Kinovea software. Independent t-test was used for comparison of experimental variables between two groups. Data were analyzed with SPSS 22. P<0. 05 was considered significant. Results: The findings showed that there is a significant difference between upper limb posture in Low-user and High-user groups (P=0. 033). There was also a significant difference in shoulder position between men and women (P=0. 002). But regarding head positioning, there was no significant difference between men and women (P=0. 436). Conclusion: Thus, it seems that considering the significant difference between the two groups mentioned for upper limb posture, we can use the results of this study to inform, prevent and improve the upper.