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Showing 4 results for Faradmal
Investigating the Correlations of results of three methods OCRA Index, Strain Index, ACGIH HAL to evaluate the risk of upper extremity musculoskeletal disorders
Mahdi Mohammadian Mastan, Majid Motamedzade , Javad Faradmal,
Volume 1, Issue 2 (Journal of Ergonomics 2013)
Abstract
Introduction: Three methods of OCRA Index, Strain Index and ACGIH HAL are proposed to assess risk factors of upper extremity musculoskeletal disorders. These methods are important in work environments to evaluate musculoskeletal disorders. Thus the aim of this study is to determine the correlation between the results of the above mentioned methods. Materials and Methods: In this cross - sectional study, a total of 150 job tasks studied in four industries . For each task, not only video taping was used to record the duration of a full cycle but also tasks were evaluated according to instructions. The correlation coefficient and the coefficient of agreement were analysed using SPSS16 and R software. Results: Correlation between the results of risk assessment methods OCRA and SI for right and left hand, were acceptable correlation (0.751) and (0.726) respectively. Also the result of agreement between the methods OCRA and HAL for right and left hands, were (0.526) and (0.595) respectively. Conclusion: This study showed that none of the two methods do not fully agree. One of the source of differences is the number and types of variables and their effects on the final score of the methods.
The validity and reliability of an usability assessment tool for a web-based software
Javad Faradmal, Javad Keshvari Kamran,
Volume 2, Issue 3 (Journal of Ergonomics 2014)
Abstract
 

Introduction: Index of usability evaluates performance, user satisfaction and increased productivity in a product. Principles of usability are effectiveness, efficiency, safety, utility, learnability, Memorability. This Study Aims to Develop a Tool to Estimate and Evaluate the Usability of Web Applications in the field of Automation Research has been determined.

Material and Methods: After extracting, an initial questionnaire to assess the usability of the standard resource for indices of validity, internal consistency and reproducibility, respectively technique for determining the content validity, test-retest method and cronbach's alpha coefficient were used. The most important steps were as follow: (1) determine the scope and dimensions of the questions (2) preparing draft questionnaire (3) appoint the members of the expert panel (4) methods, how data analysis (5) determine the acceptance criteria of the questions (6) determine the content validity index (7) determine reliability of the questionnaire (8) determine reproducibility of the questionnaire.

Results: A 50-Item questionnaire was designed as the ultimate tool. The content validity index value of 0.763 was obtained ultimately for the questionnaire. Analysis of the questionnaire responses revealed that the lower backend errors related to the reliability coefficient alpha value was equal to 0.742. Finally, the degree of reproducibility of the questionnaire, using test-retest method, was equal to value of 0.993 (p <0.001).

Conclusion: After the final questionnaire design, with good reliability and validity, it is noticeable that the designed tool is applicable on relevant softwares and may improve the quality and efficiency of the software and user interface.


Artificial Lighting and Its Relation with Body Posture in Office Workplaces
Zahra Pirmoradi, Rostam Golmohammadi, Javad Faradmal, Majid Motamedzade,
Volume 5, Issue 4 (Journal of Ergonomics 2018)
Abstract
Background: Inadequate lighting in the workplace can cause unconventional changes in the posture of office workers. Poor ergonomic conditions in the office cause inappropriate postures during work and increase pressure on the musculoskeletal system which can cause some disorders in long-term. In this study, the relationship between work environment lighting with the prevalence and severity of musculoskeletal pain among office workers has been investigated.
 
Methods: In this study, the intensity of local illumination at work surface and at the perpendicular surface (perpendicular surface to the work surface and at the height of workers eye), and intensity of general lighting was measured based on the standard of The Illuminating Engineering Society (IES) using the SEKONIC, C-7000 SpectroMaster. Also, to assess the prevalence and severity of pain of musculoskeletal disorders, a Nordic Questionnaire and a Body map index were used respectively. To assess the office work strain, Rapid Office Strain Assessment techniques (ROSA) were used. Data were analyzed by SPSS 21.
Results: The results showed that the average intensity of general lighting, local lighting at work surface and at the perpendicular surface were 30.6%, 33.9%, and 38.4% respectively, which is lower than required illumination intensity of Occupational Exposure Limits (OEL). The neck and waist had the highest prevalence of the musculoskeletal disorders among the workers. The highest frequency percentage of scores in the ROSA method was the score 5 (41.7%) which had a significant correlation with illumination intensity.
Conclusion: Illumination intensity can be considered as one of the important factors affecting posture in administrative staff. Therefore, the improvement of illumination intensity can decrease the severity of musculoskeletal pain and improve the body postures of the staff and, consequently, increase their comfort.

Investigating the Relationship Between the Risk of Psychosocial Factors and Grip Fatigue of Employees with Manual Tasks
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.

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