Showing 34 results for حیدری
Mohammad Babamiri, Rashid Haidari Moghaddam, Fakhrodin Ghasemi, Mohammad Ghaffari, Mahdi Razee, Khadijeh Bandeh Ellahi, Alireza Mortezapour,
Volume 6, Issue 3 (Journal of Ergonomics 2018)
Abstract
Background and Objectives: Nowadays, the use of the Internet among students has become widespread. Addiction to virtual networks and online games can have various consequences, including the threat of musculoskeletal system in these people. The purpose of this study was to determine the effect of addiction to social networks and online games on students’ wrist pain.
Methods: This study was conducted among 665 students. Data collection was done through three questionnaires of problematic use of online games, social networking addiction and Nordic musculoskeletal disorders. Data were compared by Chi-square and independent T-test and finally, logistic regression model was presented at a significant level of 0.05.
Results: The results showed that social network and online game addiction can increase the risk of pain in the wrists. Sex had a significant impact in the effect of social network addiction on pain in the wrist. Other results of the present study are the not significant differences in the age and level of education of the participants in the prevalence of wrist pain.
Conclusion: It can be stated that there is a likelihood of a relationship between social network and online game addiction with wrist pain. Therefore, due to high prevalence of this addiction among students, appropriate planning should be taken to reduce complications and injuries, especially in the wrist area of them.
Neda Mahdavi, Maryam Zarei, Negin Keshvari, Younes Mohammadi, Mahdi Zarei, Rashid Heidarimoghadam,
Volume 8, Issue 1 (Iranian Journal of Ergonomics 2020)
Abstract
Background and Objectives: One of the most important aspects of ergonomics is physiologic balance between human characteristics and their jobs. This study aimed to investigate the physiological characteristics of janitor, safety guard and facility workers of a work organization and determine their physiological fit.
Methods: A total of 70 staff were evaluated using Queen's college step test, N20 body composition analyzer, SECA scale, RS800CX Polar pacemaker. Descriptive statistics and analytical tests including ANOVA and Pearson correlation were used. The data was analyzed using SPSS 20.
Results: Body Mass Index (BMI) and fat percentage (Fat%) of employees were beyond the optimal range, but Waist to Hip Ratio (WHR) were in the range. Also, the average Maximum Volume of Oxygen consumption (VO2max) were 42/1±62/33 mL/kg/min and the average of working capacity (maximum Physical Work Capacity: PWCmax) were 16/63±4/46 kcal/min.
Conclusion: The results indicated that the level of some physical characteristics is inappropriate, physical fitness is poor and individual capabilities and job requirements are not in balance. Using standardized recruitment tests, providing the possibility of sports activities (by organizations) and finding integrated indicators that simultaneously take into account the physical, mental, social and environmental capabilities of individuals to determine work capacity (by researchers), can be facilitating steps to establish an ergonomic balance in the workplace.
Neda Mahdavi, Javad Faradmal, Iman Dianat, Hassan Khotanlou, Rashid Haidari Moghadam,
Volume 8, Issue 3 (Iranian Journal of Ergonomics 2020)
Abstract
Backgrond and Aim: Fatigue is a common and highly prevalent problem among workers. Muscle fatigue is the result of general fatigue that is caused by different risk factors. This research was conducted to assess grip fatigue between workers with manual tasks and its relationship to psychosocial risk factors.
Methods: In this study, Jamar hydraulic dynamometer was used to investigate the decrease in the production of grip force or grip fatigue. The grip force of 157 subjects in three job levels that met inclusion criteria recorded, three times in an 8 hours shift. The psychosocial risk factors were also assessed using the Copenhagen psychosocial questionnaire and their relationship with grip force and grip fatigue was analyzed.
Results: sixty-one percent, 62%, and 69% of employees in light, medium, and heavy tasks, respectively, experienced grip fatigue in the second phase of the study. It seems that as the power/speed increased and the tasks became more difficult, employees experienced more grip fatigue in the right hand. The declining trend of grip force and the increase in grip fatigue was more evident in heavy task jobs. No moderate or strong correlation was observed between the psychosocial risk factors and grip fatigue.
Conclusion: Because the nature of worker tasks in heavy manual tasks required more force exertion, they experienced more grip fatigue in their right hand than other workers. It is not possible to draw definitive conclusions about the impact of psychosocial risk factors on grip fatigue. Investigating the impact of cognitive loads and anthropometric dimensions on grip fatigue can be an interesting topic for future studies.
Rashid Heidarimoghadam, Ali Akbar Khasseh, Hossein Vakilimofrad, Abbas Fattahi, Mohammad Reza Amiri,
Volume 9, Issue 2 (Iranian Journal of Ergonomics 2021)
Abstract
Background & Objectives: Every scientific activity needs to know the previous related scientific activities so that its various aspects can be better investigated in order to obtain a richer intellectual heritage. So this article aims to identify and analyze the historical origins of ergonomics using two scientometric techniques named RPYS and RPYS-Co.
Methods: This applied research was conducted in a scientometrics method. The research data consists of 31239 articles in the field of Ergonomics which were indexed over the 20-year period (2000-2019) in Web of Science database. After extracting all the references of these articles, the results were analyzed using the CRExplorer software.
Results: Results showed that in the field of ergonomics, from 1700 to 2000, a total of 19 mutations occurred in the two periods of 1900-1700 and 2000-1900. The article "the information capacity of the human motor system in controlling the amplitude of movement" by Fitts (1954) was recognized as an outstanding and index work. According to RPYS-CO results, the most co-citations with index work are related to the works of 1997 and 2004, which are on Fitts Law.
Conclusion: In the period of 1700 to1900 influential works were related to psychology, biology and economics, and during 1900-2000 influential works were related to psychological theories, work environment and research methodology.
Fakhradin Ghasemi, Rashid Heidarimoghadam, Payam Khanlari,
Volume 9, Issue 3 (Iranian Journal of Ergonomics 2021)
Abstract
Background and Objectives: Hospital and medical staff use medical gloves to protect themselves and their patients from infectious agents. Wearing gloves may reduce manual dexterity and grip strength and interfere with work performance. The aim of this study was to investigate the effect of wearing medical gloves on grip strength, manual dexterity, and perceived comfort.
Methods: 20 people (10 women, 10 men) participated in this study. Participants were tested in three gloveless modes, with latex gloves and with nitrile gloves with two tests, a 9-hole pegboard and a modified pegboard. Perceived comfort in working with gloves, wearing and removing gloves was also assessed using a subjective scale.
Results: The age range of participants was 20 to 40 years with an average of 29.45 years. There was a significant difference in manual dexterity between gloveless hands and nitrile gloves in the 9-hole pegboard test. In the modified pegboard test, gloveless hand manual dexterity was significantly different from both latex and nitrile gloves. The results also showed that wearing any type of glove significantly reduced the grip strength of individuals. The worst comfort rating was given to wearing gloves.
Conclusion: The results of this study showed that wearing gloves reduces manual dexterity and grip strength. A modified pegboard test is also recommended to assess the manual dexterity of medical gloves. Latex and Nitrile gloves are difficult to wear and should be considered in designs.
Mahsa Heidari, Farshid Babapour Mofrad, Hamed Shah-Hosseini,
Volume 10, Issue 1 (Iranian Journal of Ergonomics 2022)
Abstract
Objectives: Given the benefits of controlling Body mass index (BMI) on the quality of life, BMI classification based on facial features can be used for developing telemedicine systems and eliminate the limitations of existing measuring tools especially for paralyzed people, that enable physicians to help people online when faced with situations like the COVID-19 pandemic.
Methods: In this study, new features and some previous-work features were extracted from face photos of white, black and Asian people, ages 18 to 81, with normal and overweight BMI. Faces were evaluated in three different steps. First, all faces were considered as one group. Second, they were divided into elliptical, round and square shape groups and third, they were separated based on gender. Then for each step, the performances of Random Forest (RF) and Support Vector Machine (SVM) were evaluated with all of the facial features and with selected features based on Pearson correlation coefficient. Matlab R2015b was used for implementation.
Results: The results revealed that features with higher correlation improved the accuracy of both algorithms. RF best performance using highly correlated features for 97 women and 92 men was in women and square-face groups (91.75% and 87.30% respectively), and SVM best performance was in women group (94.84%), square-face and round-face groups (84.12% and 84% respectively).
Conclusion: Accuracy of BMI classification based on facial features can be improved by categorizing faces into shapes and gender, and selecting appropriate features. The findings can be used for performance enhancement of telemedicine applications, especially for helping the differently-abled.
Omid Kalatpour, Rashid Heidarimoghadam, Iraj Mohammadfam, Maryam Farhadian, Mohammad Reza Tavakkol,
Volume 10, Issue 2 (Iranian Journal of Ergonomics 2022)
Abstract
Objectives: Risk-taking is a personality trait which plays a part in the occurrence of work-related accidents. For this reason, people who are highly risk-taking whose decision might cause accident should not be employed in critical situations. The purpose of this survey was to design and verify the validity of the risk tolerance questionnaire, suitable for control room operators, through examining the event related potential (ERP).
Methods: At first, the questions were selected from reliable scientific resources based on the conceptual model. The questions of the initial questionnaire were selected based on face validity, and then the questionnaire was filled out by 178 control room operators. At the next step, the best questions of the questionnaire were extracted using exploratory factor analysis (EFA). In terms of reliability, 42 individuals of the study group refilled in the questionnaire again after three months as a test-retest. The ERPs were assessed using electroencephalography along with Balloon Analogue Risk Task (BART). The correlation coefficient calculated between the ERPs, and risky behaviors, and questionnaire scores.
Results: One factor and 13 questions were identified as the best questions regarding EFA. Cronbach's alpha was 0.91. The Spearman correlation coefficient was calculated between the questionnaire score and risk-taking behavior as well as between the questionnaire score and P300, which was 0.38 (P = 0.01, η2 = 0.70) and 0.63 (P = 0.01, η2 = 0.99), respectively.
Conclusion: The Operator control Room Risk-Taking (ORTQ) questionnaire consists of 13 questions which can be used as an appropriate tool to assess the risk-taking trait in control room operators and also for research purposes. This questionnaire has got three personality dimensions including risk-taking nature, impulsivity and venturesomeness.
Rashid Heidarimoghadam, Alireza Mortezapour, Khadijeh Najafighobadi, Hamid Saeednia, Saeedeh Mosaferchi,
Volume 10, Issue 3 (Iranian Journal of Ergonomics 2022)
Abstract
Objectives: The importance of surgery and its high workload are not hidden from anyone. So far, various studies have been conducted with the NASA-TLX instrument and other commonly used instruments to measure surgeons’ workload. The present study seeks to investigate the relationship between the mental workload of surgeons and their productivity through the validation of specialized tools for this job in Iranian culture.
Methods: After checking the validity and reliability of "SURG-TLX" and productivity tools, they were utilized among 60 surgeons to investigate the relationship between their workload and productivity (WHO-HPQ tool). Content validity indices, Cronbach's alpha coefficient and Spearman's correlation coefficient were used to analyse the results.
Results: Both tools had good validity and reliability in Iranian culture. The results of the relationship between mental workload subscales with different dimensions of productivity showed that some dimensions of mental workload including mental needs (correlation coefficient -0.65 and significance level 0.02), physical needs (correlation coefficient -0.54 and significance level 0.04) and time requirements (correlation coefficient -0.44 and significance level 0.02) had a reverse and significant relationship with the overall productivity score. Despite the reverse relationship between the other dimensions of mental workload and the overall productivity score in surgeons, this relationship was not statistically significant. The results indicated a reverse and significant relationship between some of the mental workload and some of the productivity subscales.
Conclusion: In addition to the possibility of using these tools in the future studies in Iran, due to the direct relationship between workload and productivity in surgeons, measures can be taken to maintain the workload at a standard level and prevent the reduction of their productivity.
Nadere Seyedahmadi, Alireza Heidari, Parviz Askari,
Volume 11, Issue 1 (Iranian Journal of Ergonomics 2023)
Abstract
Objectives: The present study aimed to assess the effect of stress inoculation treatment (SIT) on occupational stress, COVID anxiety, resilience, and sleep quality of healthcare workers.
Methods: The current study was conducted based on a pre-test-post-test design with the control group. The research community consisted of healthcare workers in Ahvaz, and the research participants included 40 cases who were selected by purposeful sampling based on inclusion and exclusion criteria. The research instruments were the COVID-19 anxiety scale, resilience scale, sleep quality scale, and job stress scale. The data were analyzed in SPSS software using univariate and multivariate covariance analysis.
Results: The results of the present study demonstrated F ratios of univariate analysis of covariance for sleep quality (F=304.08 and P<0.001), COVID anxiety (F=212.99 and P<0.001), resilience (F=152.37 and P<0.001) and job stress (F=124.59 and P<0.001).
Conclusion: Due to the effectiveness of stress inoculation training on the studied variables, this training seems necessary for the health and treatment staff.
Mohammad Babamiri, Ramin Rahmani, Rashid Heydari Moghadam, Mehraneh Shabani,
Volume 11, Issue 2 (Iranian Journal of Ergonomics 2023)
Abstract
Objectives: In work environments, job stress is the main factor that can make employees lose control and provide the opportunity for the occurrence of aggression in employees. Therefore, this study investigated the role of the effort-reward imbalance model in the occurrence of bullying in the workplace.
Methods: This study was descriptive-analytical in nature. The research population consisted of employees of one of the petrochemical plants located in the south of the country. The samples (n=202) were selected using the census sampling method. In this research, two self-report questionnaires, namely the Effort-Reward Imbalance Scale and the Questionnaire of bullying actions, were used to measure the variables. Data analysis was performed using SPSS 18 software using Pearson’s correlation coefficient and linear regression.
Results: The mean scores of the participants’ age and work experience in this study were 40.13±9.32 and 15.9±9.50 years, respectively. Among the participants, 72.8% were female and 86.1% were married. In terms of educational status, 10.9% had an associate's degree, 81.2% had a bachelor's degree, and the rest had a master's degree or higher. About three-quarters of the participants were public service employees, and the rest were working on a contract basis. Based on the results of the multivariate regression model, among the variables investigated in this study, effort-reward imbalance and extreme commitment were able to significantly predict the changes in the bullying score (P<0.001).
Conclusion: Employees who feel imbalanced between inputs and outputs in the job, as well as those who have the characteristic of excessive responsibility, are more likely to display negative behaviors in the form of bullying in the workplace.
Seyed Ghafar Hoseini, Ebrahim Zarinkalam, Reza Heidary, Majid Jalili,
Volume 11, Issue 4 (Iranian Journal of Ergonomics 2024)
Abstract
Objectives: The maximum aerobic capacity (VO2max) is the most important indicator of physical fitness, which is closely related to the general health of the body. Considering the problems of laboratory measurement of VO2max, estimating VO2max by non-exercise equations will be one of the alternative solutions. This study aims to evaluate the validity of the native non-exercise equation in estimating VO2max of healthy adolescent boys.
Methods: The variables of age, height, weight, and body mass index were measured in 248 healthy boys aged 15 to 18. The subjects' VO2max was measured and predicted by exercise test and non-exercise native equation respectively. To evaluate the validity of the native non-exercise equation, Pearson's correlation, paired t-test, and Bland-Altman's agreement were used.
Results: There is a significant correlation between measured and predicted VO2max (R = 0.76, p<0.05). Also, no significant difference was observed between predicted and measured VO2max (43.10 ml/kg/min and 43.38 ml/kg/min respectively) (mean difference=0.28 ml/kg/min, P>0.05). Also, the Bland-Altman graphic diagram indicated agreement between the methods of measuring and estimating VO2max.
Conclusion: In the present study, the native non-sports equation had a high validity in estimating VO2max of adolescent boys. It seems that the use of non-sports VO2max equations can be used as a simple, safe, and low-cost tool to evaluate the maximum aerobic capacity of students at a wide level.
Fateme Rezaie Pourmashizi, Behrouz Hajilou, Rashid Heidarimoghadam, Sara Anbarian, Mehrdad Anbarian,
Volume 13, Issue 1 (Iranian Journal of Ergonomics 2025)
Abstract
Objectives: The core muscles of individuals with low back pain show a different activity pattern than the healthy group during load lifting. This issue may be due to changes in spinal control mechanisms, such as muscle synergies. The present study aimed to compare the synergy pattern of selected core muscles and lower limb muscles during load lifting and lowering with two different techniques among females with non-specific back pain in comparison with the healthy group.
Methods: A total of 18 healthy females with non-specific back pain and 18 match controls participated in this study. The activity of 8 muscles of the core and lower limbs was recorded while lifting a load of 10% of the subject's mass with stoop and squat techniques. Then, the pattern of muscle synergies was extracted using the non-negative matrix factorization algorithm. Pearson's correlation method and independent t-test were used to compare synergy patterns (P<0.05).
Results: Patients with back pain had a different muscle synergy pattern than those in the healthy group in stoop and squat techniques. The peak muscle synergy patterns of patients in both techniques were different from those of healthy subjects and were created in a different time cycle of lifting the load.
Conclusion: This study indicated that individuals with non-specific back pain use different synergy patterns during load lifting, and the body's control system may respond differently in patients with non-specific low back pain compared to healthy individuals. The changes observed in the relative weight of muscles in patients and healthy people may be caused by the changes in muscle synergy patterns, which require further studies.
Payam Heydari, Avin Ahmadian, Aram Mohamadi, Pakhshan Ahmadian, Seyed Ehsan Samaei,
Volume 13, Issue 1 (Iranian Journal of Ergonomics 2025)
Abstract
Objectives: Today, visual comfort is considered a fundamental component of man-made environments. Therefore, it is necessary to pay special attention to all factors affecting it. The present study was conducted as a systematic review to summarize the factors affecting visual comfort.
Methods: An electronic search was conducted in national and international databases, including Web of Science, Scopus, Google Scholar, Medline, PubMed, Wiley Online Library, BMJ Learning, Springer, and ProQuest. Articles were searched using keywords, such as visual comfort, architectural features, space configuration, interior design, physical factors, and lighting.
Results: Among 135 articles, the full texts of 19 articles were finally reviewed. Questionnaires were used in 53.5% of studies, while device measurements were employed in 21.4%. Physical factors were found to have the most impact on visual comfort, accounting for 51.4% of the studies reviewed. Additionally, architectural factors, space configuration, and interior design accounted for 25.7% of the impact on visual comfort in the studies reviewed.
Conclusion: The improvement of visual comfort can be achieved by influencing factors like physical elements, architectural design, space configuration, and interior design, which can lead to reduced errors, improved performance, decreased injuries from falls, and an overall increase in quality of life.
Kamal Azadi Rad, Manouchehr Haidary, Farzaneh Saki,
Volume 13, Issue 3 (Iranian Journal of Ergonomics 2025)
Abstract
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.
