Iranian Journal of Ergonomics

Relationship between Self-efficacy, Self-regulation, and Locus of Control with Job Satisfaction in Employees

Ali Afshari

Objectives: Job satisfaction is one of the most basic components of mental health, dynamism, efficiency, and creativity of employees in any job or profession. The present study aimed to determine the relationship between self-efficacy, self-regulation, and locus of control with job satisfaction in rotating shift employees of Imam Khomeini Hospital in Urmia.
Methods: The research method is correlational. The statistical population in this study included all male employees working rotating shifts at Imam Khomeini Hospital in Urmia, 150 of whom were selected as a sample based on the stratified random sampling method according to the Morgan table. This study used the Hoffman and Kashdan Emotional Self-Regulation Questionnaire, the Scherrer Self-Efficacy Questionnaire, the Rutter Locus of Control Test, and the Smith, Kendall, and Hewlett Job Satisfaction Questionnaire as data collection tools. Pearson correlation analysis and multiple regression analysis with SPSS25 were used to analyze the hypotheses.
Results: The study showed that there was a relationship between self-efficacy and job satisfaction (0.001). There is also a positive relationship between self-regulation and job satisfaction and locus of control with job satisfaction (0.001). In the components of emotional self-regulation, the relationship of all three elements of concealment, compromise, and tolerance with job satisfaction was confirmed (0.001).
Conclusion: In short, self-efficacy, self-regulation, and internal locus of control are three important factors in determining the level of job satisfaction of employees. Cultivating these characteristics in people can help increase job satisfaction and, as a result, improve the performance and productivity of organizations.

Investigating the Relationship between Presenteeism and Workforce Productivity and Job Stress

Manizhe Afrashte Fard

Objectives: Presenteeism is defined as a global phenomenon that causes problems for workers who are present at work but are not fully efficient due to illness, boredom, unwellness, or other medical conditions. The purpose of this study was to investigate the relationship between presenteeism and the levels of labor productivity and job stress among the employees of a company affiliated with the Ministry of Petroleum.
Methods: The study subjects (n=59) were randomly selected from among the official employees of a provincial gas company according to the Cochran formula. The data of the study were collected using the Stanford Presenteeism Scale (SPS-6) and Health and Work Questionnaire (HWQ). The one-sample t-test was used to check the significance of presenteeism among employees. Data analysis was performed in SPSS version 26 software.
Results: In this research, it was found that 27 individuals (46%) participating in the project were presentees, while 32 people (54%) were not. The results showed that there was a statistically significant relationship between presenteeism and the subcategories of productivity (r=0.003) and the subcategories of job stress (r=0.016).
Conclusion: In this research, it was found that higher levels of presenteeism led to lower productivity of the workforce and higher levels of job stress, which imposes high costs on the organization.

Muscular Synergy of Trunk and Hip Segments in Carrying Hand Loads with Different Weights in Healthy Young People

Saeed Ilbeigi

Objectives: Designing one-handed carrying tasks based on biomechanical findings has a significant impact on preventing musculoskeletal injuries. The present study was conducted to investigate the muscle synergy of the trunk and pelvis in the manual carrying of loads with different weights in healthy young people.
Methods: In this experimental study, 20 male volunteers performed the walking protocol without load, carrying different weights of 5%, 10%, and 15% of their own weight during unilateral manual load carrying. The electrical activity of the trunk and pelvis muscles while carrying loads of different weights was recorded using an electromyography device (Biovision). To evaluate the differences between different load-carrying conditions, a repeated measures test was used at a significance level of P≤0.05.
Results: The results showed that in the performance of manual load carrying, there was a significant difference between muscle synergy (synergy size) in all walking protocols, including 5% and 10% of body weight and 5% and 15% of body weight and between 15% and 10% (P≤05). While in the performance of manual load carrying, a significant difference was found between muscle synergy (synergy direction) in 5% of body weight and 10% of body weight, this difference was not seen in manual load carrying with 5% of body weight and 15% of body weight and also between synergy of 15% and 10% (P≥0.05).
Conclusion: It seems that the difference in muscle synergy in terms of size in unilateral manual load carrying can, with increasing load, create more tension in the back and pelvic muscles; however, the direction or angle does not change compared to the no-load state.

Correlation between Subscales of Mental Workload and Physical and Mental Dimensions of Chronic Fatigue in Small Industries and Related Jobs

Reza Raeisi

Objectives: Mental workload and chronic fatigue in the workplace are challenges that affect employees' capabilities and health. The aim of this study is to examine the correlation between the subscales of mental workload and various physical and mental dimensions of chronic fatigue in small industries and related jobs.
Methods: This descriptive-analytical cross-sectional study was conducted on employees of small industries in Eghlid with a sample size of 247 participants. Data were collected using three questionnaires: demographic information, NASA-TLX, and Chalder fatigue scale. For data analysis, Spearman's correlation test and SPSS software were used.
Results: The results showed significant differences between marital status, age groups, and work experience across different occupations, while no significant differences were found based on education level. The highest mean score of the mental workload subscales was related to the physical demand subscale, while the lowest was related to the frustration subscale. Significant differences were observed in the scores of mental workload subscales across different job categories, but no significant differences were found in the scores of physical and mental fatigue dimensions across job types. All mental workload subscales, except for performance, had a direct correlation with physical and mental fatigue dimensions, while the performance subscale showed an inverse relationship.
Conclusion: The findings of this study emphasize the importance of a more precise understanding of the relationship between mental workload and fatigue in workplace environments and could contribute to improving working conditions and the quality of life for employees in small industries.

Evaluation of the Effect of Educational Intervention on the Cognitive Performance of Taxi Drivers Exposed to Heat Stress in a City in Southern Iran

Marzieh Sadeghian

Objectives: One of the occupations that is exposed to a lot of heat stress is taxi drivers. Due to their working conditions, these people spend a lot of time standing next to their cars in the sun to pick up passengers, and they are also exposed to heat stress throughout the entire driving journey. Therefore, the present study aimed to evaluate the effectiveness of an educational intervention program on the cognitive performance of taxi drivers exposed to heat stress in a city in southern Iran.
Methods: The present study was a semi-experimental intervention that was conducted in three stages: initial assessment, training, and secondary assessment for 80 taxi drivers in two intervention and control groups. In the first stage, a general assessment of all drivers' knowledge and awareness of heat stress was performed, while cognitive parameters, including concentration skills and mental fatigue, were measured using a questionnaire. Then, training was given to the intervention group in both in-person and online formats. Two months after the start of training, cognitive parameters were measured for both intervention and control groups. Data analysis was also performed using SPSS software.
Results: The results after the intervention showed that the training significantly increased concentration skills and significantly reduced mental fatigue (P<0.001). Regarding concentration skills and mental fatigue, along with all subcategories of the two questionnaires, the results showed that there was no significant difference between these variables before the intervention between the two groups. However, the difference between the two groups was significant after the intervention (P<0.001).
Conclusion: Implementing an appropriate training program with follow-up over a period of two months to familiarize individuals with heat stress improved cognitive performance, and using follow-up training with a virtual structure improved the teaching and learning process and had an impact on individuals' performance.

The Effect of Family-work Conflict on Teachers' Emotional Burnout: The Moderating Role of Perceived Organizational Support (Study Case: Teachers in Qom City)

Hamid Rahimi

Objectives: The phenomenon of work-family conflict in organizations leads to important consequences, such as job burnout, emotional burnout, reduced job performance, and decreased individual well-being. Based on this, the aim of the present study was to investigate the effect of work-family conflict on the emotional burnout of teachers in Qom City with the moderating role of organizational support.
Methods: The research was conducted based on structural equation modeling, and the statistical population included all teachers in Qom, totaling 3,864 people, of whom 390 were selected as a sample using the Cochran formula and stratified random sampling method. Three questionnaires of work-family conflict, emotional burnout, and organizational support were used. Research data analysis was performed using SPSS version 26 and Pls software at descriptive (frequency, percentage, mean, and standard deviation) and inferential levels (structural equation model).
Results: The path coefficient of the variables showed that work-family conflict on emotional burnout (Beta=0.625, t=19.45, P=0.000) had a positive and significant effect, and perceived organizational support had a negative and significant effect on emotional burnout (Beta=0.127, t=-2.97; P=0.004).
Conclusion: Organizational support can have a moderating role in the relationship between work-family conflict and burnout. Therefore, the more the individual and his/her environmental conditions can control work-family conflict, and the more support the individual perceives from the organization, the less emotional burnout the individual will experience. Therefore, in addition to the courses it holds to increase teachers' knowledge in specialized fields, the education organization can also hold courses aimed at preparing them psychologically to deal with such stressful situations, which are sometimes unavoidable given today's life and improve their self-control and self-management skills to manage these situations.

Comprehensive Fall Prevention Strategies in Elderly: A Systematic Review

Amirmohamad Najafipour

Objectives: Falls are one of the leading causes of injury in the elderly; therefore, prevention and early intervention seem essential. Given the importance of examining and identifying factors affecting falls and the lack of such studies, it is essential to conduct this research to investigate the factors influencing falls in older adults in developing countries, with an emphasis on safety and ergonomics.
Methods: A review method was used to conduct this study. Articles from 2019 to 2024 were found using the keywords: "Fall risk factor," "Safety," "Elderly," "Fall prevention," "Home safety," and "Urban safety" on PubMed, Science Direct, and Google Scholar websites.
Results: After a total of 1,154 publications were located, 523 were chosen based on their titles, 120 were examined based on their abstracts, and 51 were chosen whose full texts were available in English. Many elements, including psychological, physical, and cognitive characteristics, ergonomic and safety tools, awareness and education, social factors, and urban services, were examined in the publications about falls among the elderly.
Conclusion: The risk factors for falls in the elderly were taken into account in this study by classifying external variables and internal factors, all of which had an impact on falls in the elderly. The results indicate that few studies have simultaneously assessed multiple factors. Therefore, it is recommended that future studies examine multiple factors concurrently, considering the impact of awareness factors.

Ergonomics Situation of School in Iran: A Systematic Review

Mohsen Poursadeghian

Objectives: Various factors, including a lack of attention to the adaptation of educational spaces, can significantly impact the quality of education. Consequently, this study aims to comprehensively review and analyze all research conducted on school ergonomics in Iran.
Methods: A bilingual search was conducted in this study utilizing Persian keywords such as "Student," "Elementary, middle or high school," and "Physical, environmental, and general ergonomics," along with their Latin equivalents. This search was performed across databases, including Google Scholar, PubMed, Web of Science, and Scopus, covering the period from the inception of research in Iran until 2024. Subsequently, articles relevant to the topic were collected and examined according to the established criteria.
Results: Among the identified articles, only 30 were recognized as relevant to the study's objectives, focusing on physical, environmental, and general ergonomics. A comparison of these studies revealed an upward trend in musculoskeletal disorders, with many of these issues linked to ergonomic problems in schools, including the mismatch between students' body dimensions and the desks and chairs used, as well as improper carrying of school bags.
Conclusion: The poor ergonomic conditions in Iranian schools have led to an increase in musculoskeletal disorders among students. It is vital to evaluate these schools based on ergonomic standards and implement necessary enhancements. Furthermore, it is important to raise students' awareness about proper task performance and appropriate backpack usage.