Iranian Journal of Ergonomics

Effect of Six Weeks of Corrective Exercises on Proprioception, Head and Shoulder Posture, and Neck Muscle Strength in Male Students who Use Mobile Phones

Manouchehr Haidary

Objectives: In recent years, the use of smartphones has impacted people's lifestyles and contributed to postural abnormalities, particularly in the spine. Therefore, the present study aimed to study the effect of six weeks of corrective exercises on proprioception, head and shoulder posture, and neck muscle strength in male students who use mobile phones.
Methods: The present study employed a quasi-experimental design with a pretest-posttest approach and a control group. The statistical population consisted of 34 students (mean age 15.34) from Razan, Iran, who were randomly assigned to two groups of 17 each (experimental and control). The experimental group's exercise program lasted 6 weeks, consisting of 3 sessions per week (totaling 18) and lasting 1 hour each. During this period, the control group did not receive any exercise. Before and after the intervention, head forward was measured using imaging; neck muscle strength was assessed with a dynamometer; neck proprioception was evaluated with a laser pointer; and shoulder protrusion was measured with a graduated ruler. The data were analyzed using both correlated and independent t-tests in SPSS.
Results: According to the findings, head forward (P=0.001), shoulder forward (P=0.001), neck muscle strength (P=0.001), and neck proprioception (P=0.001) improved in the experimental group after implementing the training protocol. However, no significant improvement was observed in the control group (P=0.425).
Conclusion: The study demonstrated that the corrective exercise intervention was successful in improving proprioception, head and shoulder posture, and neck muscle strength in male students who used mobile phones. Given the high effect size reported for corrective exercises, it is recommended that this exercise program be utilized to enhance these variables.

Usability Evaluation of the Chargoon Office Automation System Using A Mixed User- and Expert-Centered Approach (Heuristic Assessment)

Siavash Etemadinezhad

Objectives: Office automation systems are essential for optimizing administrative processes, reducing human errors, and improving organizational efficiency. However, their effectiveness depends on usability and the quality of user interaction. This study assesses the usability of the Chargoon office automation system at Mazandaran University of Medical Sciences using a mixed-methods approach, addressing gaps in prior evaluations of similar systems in Iranian academic settings.
Methods: A mixed-methods design was employed, with the quantitative component using the standardized System Usability Scale (SUS) and the qualitative component involving heuristic evaluation based on Nielsen's 10 principles, conducted by 5 UX experts. A total of 240 employees and faculty members were selected through simple random sampling. Performance data, including task completion time and error rates for six frequent tasks, were collected and analyzed using ANOVA and Pearson correlation in SPSS software (version 26).
Results: The mean SUS score was 64.83 (±12.84), indicating acceptable usability with room for improvement. The task “sending a letter to multiple recipients” had the highest error rate (15.2%) and the longest completion time (57.3 seconds). Heuristic evaluation identified 99 issues, primarily in system feedback (25%) and error prevention (20%).
Conclusion: The Chargoon system demonstrates moderate usability but requires targeted improvements in interface design, feedback mechanisms, and error prevention to reduce cognitive load and operational costs in academic settings.

Investigation of the Effect of Ergonomic Intervention on Job Burnout and Resilience of Nurses

Leili Rabiei

Objectives: Healthcare staff, due to the nature of their job, are exposed to various occupational hazards, including ergonomic stressors, which can affect their health and lead to job burnout. The present study aimed to investigate the effect of ergonomic intervention on job burnout and resilience among employed nurses.
Methods: This semi-experimental study was conducted with 70 nurses employed at Shohada Lordegan Hospital in Lordegan, Iran, between 2018 and 2019. The study units were randomly assigned by block randomization into two groups: an intervention group and a control group. The ergonomic intervention consisted of four stages (education, work modification, a regular exercise program with supervision, support, and follow-up) applied to the intervention group. The control group received no intervention. Data were collected using a demographic questionnaire and the Maslach Burnout Inventory. The mean scores before, immediately after, and three months after the intervention were compared using SPSS (version 23) with an independent t-test, chi-square, and repeated measures analysis of variance (ANOVA).
Results: There was no significant difference in the mean job burnout score between the two groups before the intervention (p > 0.05). However, after the intervention, this difference became significant, with the intervention group showing less job burnout and greater resilience compared to the control group (p < 0.001).
Conclusion: The findings of this study showed that implementing ergonomic interventions among nurses can increase resilience and reduce job burnout. Given the effectiveness of the intervention, it is recommended that ergonomic training programs be included in nursing educational curricula.

The Effect of Pillow Type and Sleeping Posture on Cervical Angle and Perceived Comfort

Teimour Allahyari

Objectives: Pillows play a crucial role in supporting muscles and maintaining the natural posture of the neck during sleep. The present study aimed to measure and investigate the effect of pillow shape, filling material, and sleeping posture on cervical angle and perceived comfort during sleep.
Methods: Ten participants (five males and five females) with a mean age of 26.7 years participated in this study. Each participant used four pillows (two cylindrical and two rectangular, one with wool content and the other with memory foam) for one hour (30 minutes in the supine position and 30 minutes in the lateral position). During the experiment, the cervical angle was measured using a Kinect sensor. At the end of each 30-minute session, the participants were asked to report their perceived comfort level using a visual analogue scale (VAS).
Results: Analysis of variance revealed that the cervical angle in the cylindrical wool pillow with the supine posture was significantly greater than in other conditions (P < 0.01). The smallest cervical angle was observed with the rectangular memory foam pillow in the lateral posture. Comparison of the effects of sleeping posture on cervical angle showed a significant difference between the two postures (P < 0.01). The highest perceived comfort was reported in the lateral posture using a cylindrical pillow.
Conclusion: The results indicate that pillow shape, material, and sleeping posture significantly affect cervical angle and perceived comfort. In this study, a rectangular memory foam pillow was superior in terms of angle, and a cylindrical pillow was superior in terms of comfort. Therefore, selecting an appropriate pillow based on sleeping posture may help improve comfort and maintain proper cervical posture during sleep.

Evaluation of Luminance and Illuminance and Their Relationship with Visual Fatigue among Users of Video Terminals at Tabriz University of Medical Sciences in 2024

Rasoul Hemmatjoo

Objectives: Nowadays, electronic devices, such as computers, mobile phones, and tablets, have played a crucial role in people's work and lives. The main complaint of users of video terminals is eye symptoms caused by prolonged use. This study aimed to evaluate the intensity of luminance and illuminance and their possible relationship with visual fatigue in users of video terminals at Tabriz University of Medical Sciences.
Methods: This cross-sectional study included 171 users of video terminals at Tabriz University of Medical Sciences. In this study, the local illuminance intensity at the work surface and the luminance intensity from the screen at the user's eye level were measured. A 15-question visual fatigue questionnaire was used to assess visual fatigue. The results were analyzed using paired t-tests and chi-square tests using SPSS software (version.16).
Results: In this study, the average local illumination intensity on the desk was 306.6 lux, and the average luminance intensity was 73.9 cd/m². The local illumination intensity was lower than the recommended level in 41.6% of the cases. No statistically significant relationship was observed between illumination intensity and users' visual fatigue during the study, nor between users' luminance and visual fatigue. The results of this study showed that visual fatigue at the end of the work significantly correlates with an individual's visual fatigue at the beginning of the work. The results of this study also showed a significant relationship between visual fatigue and the type of work.
Conclusion: The results of this study showed no relationship between luminance and illuminance intensity and visual fatigue. According to the findings of this study, it is recommended that, if possible, the time to start working with visual terminals should be when there is no feeling of visual fatigue. Also, since one of the factors affecting visual fatigue is the type of work, it is recommended that users manage their job in such a way that they are mostly inactive (reading the page).

The Impact of Occupational Categories on Foot Pain and Functional Performance: A Cross-Sectional Study Using the Foot Function Index (FFI)

Mahmood Reza Azghani

Objectives: Musculoskeletal disorders (MSDs), particularly foot problems, are among the leading causes of reduced quality of life and work productivity. Evidence suggests that occupational conditions and daily activities play a crucial role in the development of foot pain. This study aimed to examine the relationship between occupational status, severity of foot pain, and functional impairment in various occupational groups using the Foot Function Index (FFI).
Methods: This cross-sectional study included 2,848 participants from East Azerbaijan Province, Iran. Based on occupational status, participants were categorized as employees, self-employed, housewives (only women), and students. Data were collected using the FFI questionnaire. The data's normality was tested using the Kolmogorov–Smirnov and Shapiro–Wilk tests. Since the distribution was non-normal, inter-group comparisons were performed using the non-parametric Kruskal–Wallis test, followed by pairwise comparisons with the Mann–Whitney U test and the Bonferroni correction, as necessary.
Results: The results revealed that students, both men and women, reported the highest levels of foot functional problems, while employees and self-employed individuals had lower FFI scores. Among women, housewives reported fewer problems than students. Statistical analyses confirmed significant differences among the occupational groups (P < 0.001).
Conclusion: This study demonstrated that occupational status is directly associated with foot pain and functional impairment. The results highlight that students, as a high-risk group, require special attention in preventive programs and orthopedic and ergonomic interventions. Identifying the impact of occupational factors on foot health can provide a basis for designing strategies to improve occupational health and reduce the burden of MSDs.

Evaluation of the Interventional Effect of Ergonomic Skills Training Programs on Organizational Citizenship Behavior and Employee Productivity (A Case Study of Employees Working in the Azar Oil Field)

Mohammad Reza Omidi

Objectives: In high‑risk operational environments, such as oil fields, physical and psychological factors can undermine employee productivity and positive organizational behaviors. The present study aimed to investigate the effect of ergonomic skills training on organizational citizenship behavior (OCB) and employee productivity among operational staff at the Azar Oil Field in Mehran, Iran.
Methods: This quasi‑experimental study, using a pretest–posttest design with a control group, was conducted on 40 male operational workers. Participants were randomly assigned to an ergonomic training group or a control group (20 individuals in each). Data were collected using the OCB Questionnaire developed by Podsakoff et al. (1990) and the Employee Productivity Questionnaire by Hersey and Goldsmith (1980). Paired t‑tests were applied to compare pretest and posttest scores within each group, independent t‑tests were used for between‑group comparisons, and analysis of covariance (ANCOVA) was employed to control for pretest scores.
Results: Following the four‑week ergonomic training intervention in 2024, with a follow‑up period of equal length (from the start of training to posttest), the intervention group demonstrated a significant increase in total OCB scores (from 105.6 to 118.4; +12.1%) and employee productivity scores (from 128.8 to 145.6; +13.0%) (p < 0.001). The most significant improvements in OCB were observed in altruism (+15.3%) and conscientiousness (+14.8%). In productivity, improvements were seen in motivation (+16.2%) and ability (+15.4%). Cohen’s d effect sizes ranged from 1.78 to 2.20, indicating very high practical significance. No significant changes were observed in the control group during the same period (p > 0.05).
Conclusion: Ergonomic skills training led to substantial improvements in OCB and productivity among employees in the Azar oil field. These findings underscore the strategic value of investing in ergonomic training as a practical approach to enhancing individual and organizational performance in high‑risk work environments.

An Analytical Perspective on Human Reliability Assessment and Human Error Risk Studies (2010–2023): Exploring the Role of Artificial Intelligence and Lights-Out Manufacturing

Abbas Mohammadi

Objectives: As industrial systems become increasingly complex and technologically advanced, the human role in ensuring safety and efficiency remains indispensable. This study aimed to present a comprehensive review of Human Reliability Assessment research published between 2010 and 2023. It compares human reliability assessment (HRA) methodologies with emerging technologies, such as artificial intelligence and lights-out manufacturing, identifies existing research gaps, and analyzes the analytical techniques employed and the industrial sectors addressed.
Methods: A systematic search of major scientific databases using domain-specific keywords yielded over 230 publications. After removing duplicate studies, 180 articles were selected for detailed analysis. Each article was evaluated based on methodology, industrial application, country, institutional affiliation, and publishing outlet.
Results: The results indicated that the most frequently applied approaches in HRA research were the systematic human error reduction and prediction approach (SHERPA), cognitive reliability and error analysis method (CREAM), and fuzzy mathematics. The United States, China, and South Korea emerged as leading contributors to this field. The findings revealed that neither qualitative nor quantitative methods alone are sufficient to fulfill the three core objectives of HRA: error identification, probability estimation, and control design. Therefore, a hybrid approach was recommended by integrating SHERPA and Tecnica Empirica Stima Errori Operatori (TESEO). SHERPA provides comprehensive coverage of error identification and the design of effective control measures, while TESEO facilitates rapid, conservative probability estimation. These methods provided a practical and efficient framework for achieving HRA objectives within operational constraints. Additionally, ten key research gaps were identified.
Conclusion: The SHERPA–TESEO hybrid framework presents a viable strategy for achieving the core goals of HRA. Nonetheless, a shift from static to dynamic and data-driven models is necessary in the context of intelligent environments and operator-free production. Recommended developments include revising SHERPA’s cognitive task classifications, recalibrating TESEO's adjustment factors, and integrating real-time data with human–artificial intelligence (AI) interaction. These advancements are expected to significantly enhance real-time prediction of human error risks and support timely intervention strategies.