Journal of Health and Safety at Work

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Introduction: work related musculoskeletal disorders are the most wide spread type of occupational diseases among workers. Awkward body postures during work and manual material handling are among the most important risk factors of musculoskeletal disorders in different jobs. Due to importance of recognizing these factors prevalence and risk factor of work related musculoskeletal disorders, this research was aimed to study the among employees of Kashan City’s Saipa automobile industry in 2011.

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Material and Method: This study is a descriptive-cross sectional study conducted among workers with manual material handling 37 activities and 84 work duties. To recognize musculoskeletal disorders, body map questionnaire was applied and occupational risk factors were evaluated using Key Index Method (KIM). Data was analyzed using SPSS and Excel software.

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Result: Highest prevalence of musculoskeletal disorders was in low and upper back region (%92). Based on the results from KIM, workers in the installing the tire, shuttle-aided fitting of seat, and engine work station had higher risk level with the scores of 66, 52 and 52, respectively. Risk level among three individuals (%3.6) was at 1, 40 (%47.6) at 2, 38 (%45.2) risk level 3, and 3 (%3.6) at 4.

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Conclusion: Awkward body posture, improper twisting and flexion of low back were major risk factor among worker doing manual material handling tasks. Regarding the high prevalence of musculoskeletal disorders, appropriate ergonomic interventions such as engineering and organization interactions can reduce this risk factors (posture, heavy load, duration, workplace conditions) as much as the risk level reach to an acceptable level.

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Introduction: Train driving is a high responsibility job in railway industry. Train drivers need different cognitive functions such as vigilance, object detection, memory, planning, decision-making. High level of fatigue is one of the caused factor of accidents among train drivers. Numerous factors can impact train drivers’ fatigue but high level of workload is a key factor. Therefore, the aim of the present study was to investigate workload and its relationship with fatigue among train drivers in Keshesh section of Iranian Railway Company.

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Material and Method: This descriptive analytical study was done among 100 train drivers in Keshesh section of Iranian Railway industry. They were selected by simple random sampling. The NASA-TLX workload scale and Samn-Perelli fatigue scale were respectively used to investigate workload and fatigue. Data were analyzed by Paired t-test and Spearman correlation coefficient.

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Result: According to the NASA-TLX results, effort and mental workload with the mean score of 74/22 and 73/31 were respectively the most important attributes of workload among train drivers. No significant relationship was observed between workload and level of fatigue before departure and half an hour before reaching the destination station (P>0.05). However, the relationship between of workload and level of fatigue half an hour before the end of shift (on the way back to the origin station) was statistically significant (P=0.048) among the sample population.

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Conclusion: Effort and mental workload were the most important attributes of workload among train drivers. By focusing on these two variables and adopting fatigue management programs, fatigue and workload can be controlled and the efficiency of the whole system can be enhanced accordingly.

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Introduction: Manual material handling activities in long and short periods may lead to complications such as laceration, fracture, cardiovascular stress, muscle fatigue, and musculoskeletal disorders especially in the vertebrae column. The purpose of this study was to assess manual handling of oxygen cylinders by casting workers and to implement ergonomic intervention to reduce the risk of musculoskeletal disorders.

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Material and Method: This is an interventional study conducted among 18 male workers of a steel casting unit. Assessment of manual handling of oxygen cylinders, was done using in order Snook tables. The manual handling of oxygen cylinders was changed to mechanical handling and making a box with the capacity of 16 oxygen cylinders which can be moved by crane.

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Result: According to the results, lifting and lowering cylinders was not suitable for most of the workers. Moreover, caring, pulling and pushing was suitable for less than 10 percent of the workers. Condition of lifting cylinders by fire workers was suitable only 25 percent of them. According to the snook tables material handling activities must be suitable for at least 75 percent of workers.

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Conclusion: With the implementation of ergonomic intervention is casting unit, the risk of exposure to musculoskeletal disorders caused by manual handling of oxygen cylinders was eliminated and safety of employees against the risk of explosion of the cylinders in comparison with before the intervention was improved.

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Introduction: Job design approach is one of the significant concepts in ergonomics Experts believe that integration of macro ergonomics and job design can lead to improved productivity in the organizations. Therefore, this study examined the relationships between job design, performance and job satisfaction.

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Methods and Materials: This cross - sectional study was done in 11 branches of one of the bank in Hamadan. Job Design Questionnaire, Job Satisfaction Questionnaires and Bank Performance Indicator were used in order to collect data. spearman correlation coefficient was used for determining the correlation between each two variables.

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Results: This study showed that the motivational approach was the minimum approach (3.8%), and the mechanical approach, was the dominant approach (74.7%) in the study branches and the majority of branches had an average level of job satisfaction. Moreover, there was a significant positive correlation between job design (motivational and cognitive approaches) and job satisfaction. In addition, the results showed that between job design (Motivational approach) and satisfaction were significantly correlated with performance, (p = 0.05).

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Conclusion: Regarding the role of job design in job satisfaction and employees, performance, it can be stated that job redesign towards a motivational approach and considering the principles of ergonomics in the workplace, can play an important role in efficiency and productivity of an organization.

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Introduction: Manual material handling (MMH) is the most common cause of work-related Musculoskeletal Disorders (MSDs). Prevention of MSDs is highly critical. The aim of this study was to assess risk of carpets manual handling by retail workers, and to implement ergonomic interventions in order to reduce risk of MSDs.

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Material and Method: This interventional study was conducted among 36 workers in 19 retailer sites of a textile corporation. Ergonomics assessment of the retailers was done using the comprehensive risk assessment model of the British Carpet Foundation. Moreover, the Nordic Musculoskeletal Questionnaire was used to determine the prevalence of workers’ MSDs. Reassessment was conducted after implementation of the ergonomics interventions.

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Result: The mean age and work tenure of participants were 36.28 and 16.2 years, respectively. The results of Nordic Questionnaire before intervention showed that overall 37.8% of the workers had experienced pain at least once during the past year, with the highest frequency belonged to the lower back (75%), shoulder (61%), and neck and upper back (55%), respectively. After implementing the interventions, the prevalence of MSDs reduced to 23.5%. The results of risk assessment before and after the interventions showed that of the 19 retailer sites, six sites were improved from poor to average state, and one site showed improvement from average to good condition.

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Conclusion: By implementing ergonomics interventions in carpet delivery sites, the risk factors of MSDs, induced by manual carpet handling, were reduced and safety and ergonomic conditions of the retailers were improved, compared to the previous conditions.

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Introduction: Children have been known to spend most of their time at school. They learn their sitting habits in this period of time. Incorrect sitting postures and inappropriate school furniture can result in abnormalities in the vertebral column, back pain, neck pain, Fatigue and discomfort. Hence, this study was aimed to examine the match between students’ body dimensions and existing benches and desks dimensions in Hamadan female primary schools.

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Material and Method: In this study, 624 students of Hamadan female primary schools were investigated and some of their anthropometric dimensions including shoulder height, elbow height, knee height, popliteal height, popliteal-buttock length and hip breadth were measured. In this sense, a chair (with adjustable height, depth and elbow support) and a caliper with movable jaw were used for measurement of anthropometric dimensions. The measurements were performed in a way that thighs were in full contact with the seat, there was a right angle between the thighs and legs, the feet were in full contact with the movable pedal, the trunk was straight and the back and hips were in full contact with the backrest. Following, the match of the dimensions of existing benches and desks with the appropriate dimensions (based on the students’ anthropometric dimensions) were examined.

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Result: The results showed that the seat height, seat depth, seat width, back rest height, desk height, underneath desk height were in acceptable rangefor 10.1%, 17.3%, 5.6%, 53.5%, 1.9% and 31.1% of students, respectively.

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Conclusion: Despite differences in the body dimensions of primary school students, there is no regularity in using of school furniture. Overall, the dimensions of existing benches and desks are not matched with the anthropometric dimensions of students.

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Introduction: Safety signs provide information,related to hazards or dangers in the industry,in form of instructions. These signs are effective as long as they are designed in accordance with principles of ergonomics and design cognitive features. The purpose of this present research was to study the relationship between cognitive features of signs and ability to guess, and to develop the relevant regression model.

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Materials and methods: This descriptive cross-sectional study was carried out on 100 employees in a petrochemical industry complex. A three part questionnaire was used to collect required data while first part of the questionnaire dealt with demographic information, second part included cognitive features of signs designand the third part proceeded on testing the ability to guess. Then, a regression model was developed to determine the relationship between cognitive features, and the ability to guess.

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Results: Mean and standard deviation obtained for the ability to guess the total study signs were 63.73 and 4.36, respectively. The feature of “familiarity” obtained the lowest possible score (49.15). The “semantic closeness” (β=0/390) and “meaningfulness” (β=0/369) had the highest correlation with the ability to guess safety signs.

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Conclusion: According to results of this study, use of principles of ergonomic design of signs and training are necessary to promote the ability to guess the safety signs to the minimum available standards. Therefore, it is possible to balance cognitive features especially “familiarity”, with the lowest score, and “meaningfulness” and “semantic closeness”, with the highest influential relationship with the ability to guess of signs. The developed regression model for this industry can be used to predict the ability to guess of safety signs in future studies

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Introduction: The healthcare system is one of the largest sectors in most countries and is a socio-technical system in which people play a preponderant role. Nowadays medical work systems are facing three major challenges: 1) Healthcare costs, 2) Quality and patient demands and 3) complexity of healthcare. These problems show the necessity of applying ergonomic models in the healthcare sector. The aim of this study was to review the practical ergonomic models in healthcare system.
 

Material and method: For this review article, the authors searched through ScienceDirect, PubMed, ProQuest internet databases from 2005-2014 using the following keywords: Healthcare, Ergonomics, Human factors and model.
 

Result: Overall, 85 articles were reviewed. By evaluating articles' titles, 30 articles related to the study subject were chosen. Then, reviewing the abstracts resulted in 15 articles and in the final step 5 full-text articles were selected which described practical models of ergonomics in healthcare: 1) SEIPS, 2) DIAL-F, 3) Extended Patient-Staff-Machine-Interaction, 4) Adapted Medical-Task and 5) Recursive Hierarchical Task-Process-Task-Model.
 

Conclusion: Most of the published studies emphasize on application of ergonomic models in healthcare centers since these models may reduce their problems. These ergonomics approaches support patient-centered treatment processes, user-oriented design of medical environments, efficient utilization of resources and increase motivation of clinical staff.

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Introduction: In theexperienceof pain,thesensory andthe emotional components should be considered. Emotionalcomponents of the painincludea variety of emotional states which depression is the most importantone. Thus, in this study, first, musculoskeletal pain was compared between depressedand non-depressed industrial workersand then otherphysical anddemographicfactorsinfluencing thedepression andmusculoskeletal disorderwere studied.
 

Method and material: Thiscross-sectional and descriptive-analytical study was conductedin 2012, among 179 industrial workers in Shiraz city.In this study,the participantswere selected throughcensus.The data collection instruments were three questionnaires including Body Discomfort Chart (BDC), visual analogue scale type, Beck Depression Inventory (BDI) and demographic informationquestionnaire. The collected data were analyzed using SPSSsoftware version 16. Mann-Whitney and Kruskal-Wallis statistical tests wereemployedfor comparison of variables and Kendall correlationwas used for determining the relationship between variables.
 

Results: Findings of the study showed that the maximum (19%) and the minimum (3.4%) painwere belonged to back and arm/forearm, respectively. Furthermore, 36.2% of participantshad a low-to-acute level of depression. Comparison of musculoskeletal disorders betweendepressed and non-depressed workers with Mann-Whitney Test manifested a significant different in head/neck, back,left hand/wrist,right hip and knee (p<0.05).Also Kruskal Wallis statistical test showed no significant differences in depression levelamong various occupational groups,however, painsignificantly differed among various groupsin a way that its rate was higher for office workers,comparing to other groups.
 

Conclusion: The higher score of depression among workerswith musculoskeletal pain can be due to failure in pain relief achievement. Psychological problemsthatoccurfollowingchronicpainarerelated to continuous discomfort, frustration and thinking about the pain. This situation causes the feelings of inadequacy and inefficiency and consequently the increase ofprobability of depression.

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Introduction: Workplace design is one of the factors that can influence comfort, performance, productivity and the health status of employees. The effects of this factor on human’s productivity and performance are studied in the domain of ergonomics. The impact of workplace design on workers’ productivity and performance can be determined by investigation of the quality of the design. The main purpose of the present study was to investigate the influence of workplace design on productivity of the bank clerks.

Material and Method: Samples in this cross-sectional study were comprised of 150 employees of 22 different branches of a bank in Tehran city. Data collection tools included demographic questionnaire and a questionnaire related to the effects of workplace design on employees’ productivity, developed by Hameed and colleagues. Correlation and regression statistical tests were used in order to analyze data.

Result: According to the results, the mean (±SD) for age and job tenure of participants were 37.2(±6) and 13(±7) years, respectively. Of the surveyed demographic features, a significant relationship was observed between age and scores belonging to the temperature and furniture (P-value<0.05). In addition, there was a significant association between employees’ productivity and the noise (P-value=0.044) and spatial arrangement of environment (P-value=0.048).

Conclusion: Overall, appropriate and high quality design of work environment can improve productivity of bank clerks. In other words, employees’ productivity can be enhanced by comfortable and ergonomic design of working environment and also by considering their needs.

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Introduction: Quality of Work Life (QWL) is a new form of job satisfaction which involves ones feelings about all aspects of their job. The aim of this study was to assess the psychometric properties of the Persian version of WRQoL-2 questionnaire for use in the nursing community.

Material and Method: In this study, backward translation method was used in order to verify the linguistics stability. Then, the cross-sectional study was conducted among 270 nurses working in a hospital, affiliated to Tehran University of Medical Sciences. Reliability and construct validity was investigated using test-retest and factor analysis, respectively. In addition, discriminant validity was assessed by comparing QWL mean scores of nurses satisfied with their salary and those who were dissatisfied.

Result: Regarding the reliability, it was observed that the repeatability coefficient were at an acceptable level for all dimensions of the WRQoL-2questionnaire. According to factor analysis, six components were identified with some questions in different groups compared to the original questionnaire. Considering discriminant validity, all components, except Stress at Work, obtained P-value less than 0.05.

Conclusion: Based on the acceptable level of reliability and validity of the WRQoL-2 questionnaire, use the questionnaire to assess the quality of work life of nurses is recommended.

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Introduction: Pharmacies are one of the main elements of the service chain in the health system in each country. Therefore, it is important to identify characteristics of the job as well as the health issues of the employees of this business. The aim of the current study was to investigate the ergonomic issues of pharmacies.

Material and Method: This qualitative study was conducted using content analysis during a 5- month study in the pharmacies of Maragheh city, Iran. Data was collected using focus group discussion. Thirty individual including 12 Pharmacists, 12 pharmacy technicians and 6 inspectors of deputy of the food and drugs office  participated in five meetings. Data analysis was carried out simultaneously using the conducted content analysis.

Result: Using content analysis method 23 ergonomic issues were identified in the studied pharmacies. These issues were categorized into three broad categories based on the classification of the International Ergonomics Association (physical, cognitive, and organizational issues). The results showed that from ergonomic point of view, different issues of all three categories such as work postures, work space and layout, mental workload and work-rest schedules are of great importance for staffs. Some issues were more emphasized by personnel, themselves.

Conclusion: Unlike what appears at first, pharmacies as a work environment have multiple issues related to workforce health. Therefore, the occupational health and ergonomic evaluation of pharmacies that has been neglected should be taken into account by ergonomic researchers. Also, interventions to promote the ergonomic level of pharmacies require attention to all aspects of ergonomics. The results of this study can be used as a basis for promoting the regulations of establishment and utilization of pharmacies as well as ergonomic assessment of them.

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One of the main goals of all societies whether in developed or developing countries is sustainable development and quality of life improvement. Both of the mentioned fields are known as critical subjects for urban planners, health care systems authorities, organizations and industrial sectors managers. Sustainable development is a global and human-centered approach. Also, ergonomics as a multidisciplinary science has a user center approach in which the quality of life plays a prominent role. The main objective of this article is developing a synergy between ergonomics and sustainability. This research consisted of two parallel phases. The first phase included a review in which two keywords of “ergonomics and sustainability” were considered in PubMed and EBSCO. After following the including and excluding criteria, 12 final articles were assessed. The second phase, was a descriptive study based on questionnaires among 38 participants. According to articles, in-depth evaluation and data gathering throughout questionnaires, it seems that to make a synergy between ergonomics and sustainability especially based on social aspects of both mentioned firms will be ended to effective and feasible planning towards industrial ergonomics and work-related quality of life.  

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Introduction: Nearly a third of people work in jobs that use voice to be part of their work. Teachers as the largest group of professional vocal users, are at risk of vocal disorders. The aim of this study was to investigate the effect of different risk factors on vocal disorders in teachers.  
Material and Methods: This is a cross-sectional and descriptive-analytic study that was conducted on 73 primary and secondary male and female school teachers in Saveh in 2017 by random sampling. The researcher-made questionnaire on risk factors affecting verbal disorders with the aim of identifying risk factors and a Voice Handicap Index (VHI) questionnaire (30 items) aimed at evaluating verbal disorders and symptom questionnaire were used in this study. All of them have been shown to be valid and reliable in previous studies. Data were analyzed using t-test and chi square statistical tests by SPSS ver.24.
Results: The reliability of the researcher-made questionnaire on the risk factors affecting vocal disorders was confirmed by Cronbach’s alpha (0.736) and its validity was confirmed by the experts regarding the adequacy of the number of questions, the lack of ambiguity and the assessment of content fitness. According to our gathered data, vocal disorders were observed in 55% of the teachers. Also the results showed the rate of vocal disorders in female teachers is far higher than male teachers. Functional disturbance of vocal cords and allergy as general risk factors, teaching tools and poor air quality as environmental risk factors and inadequate vocal rest and job stress as occupational risk factors contributed to increasing vocal disorders in teachers. Among the symptom associated with verbal disorders in teachers, vocal fatigue and hoarseness were more common in comparison with other symptoms.
Conclusion: Due to the prevalence of vocal disorders in half of the teachers and the impact of general, environmental and occupational risk factors, it is necessary to identify and control the risk factors of vocal disorders in teachers. It can also be concluded that teachers can enjoy a healthy voice by considering the principles of ergonomics and occupational health.

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Introduction: Usability has been defined as the extent to which specific users can efficiently use a product to achieve specific goals. Along with the increased number of the elderly population, there is a need for user-centered products for this group of people. Smartphones are widely used products in modern society. USE (Usefulness, Satisfaction, and Ease of use) questionnaire is an easy-to-use, quick, and accurate instrument to assess product/service usability. Thus, this study was done to determine the validity and reliability of the Farsi version of the USE questionnaire to evaluate the usability of smartphones for elderly users.
Material and Methods: The USE questionnaire was developed by Lund (2001) to assess usability, considering four separate dimensions: usefulness, satisfaction, ease of use, and ease of learning. This is a 30-item questionnaire that evaluates usability on a 7-point Likert scale. In order to assess the face and content validity of the questionnaire, a panel of nine experts was asked to rate the relevancy, clarity, simplicity, and necessity of each question using the Likert scale. Subsequently, the Content Validity Ratio (CVR) and Content Validity Index (CVI) were computed. In order to confirm the reliability of the questionnaire, two methods of internal reliability and test-retest reliability were used. In this sense, Cronbach’s alpha was calculated as the measure of internal reliability. Cronbach’s alpha equal to and above 0.7 was considered the minimum acceptable value. To measure the test-retest, 50 old adults (aged 60 years old and above) were asked to answer the questionnaire twice at a two-week interval. Then, the Pearson correlation coefficient was calculated between the two sets of scores. Also, the receiver operating characteristic (ROC) curve was utilized for specifying its sensitivity, specificity, and cut -off point
Results: Based on the comments of the expert panel, CVI scores of all questionnaire items were above 0.78, whereas four items rated less than 0.78 in terms of CVR scores; and, consequently, were removed from the questionnaire. Moreover, according to the reliability assessment results, both internal correlation and test-retest scores obtained acceptable values. Specifically, Cronbach’s alpha coefficient for usefulness, satisfaction, ease of use, and ease of learning were 0.771, 0.862, 0.756, and 0.798, respectively. In the ROC curve, the cut-off point was reported as 4.88 with the sensitivity and specificity of 97.8% and 75%, respectively, and area under the ROC curve at this cut-off point was obtained 81%.
Conclusion: Comparing a product’s characteristics with standards is a prerequisite to determining the level of usability of that product. The Farsi version of the USE questionnaire is a reliable tool for measuring usability with satisfactory validity and reliability. This questionnaire can be used in future studies in smartphone usability.

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Introduction: Ergonomics culture emphasizes ergonomics policies, goals, and programs that create behavioral, environmental, and structural reforms in the governing environment of the organization. The present study assesses the ergonomics culture dimensions in the North Tehran Health Center office building through the Delphi method and an expert questionnaire.
Material and Methods: The Delphi method was used to develop an expert questionnaire. The evaluation criteria were determined based on the engineering dimensions of human factors and the organizational culture factor model. Besides, the sub-criteria were specified based on the macro-ergonomics approach. In this case, the most critical sub-criteria were chosen using 15 experts and the Delphi method. Thus, a questionnaire was developed with 15 questions. The ergonomics culture criteria were classified considering the frequency of negative responses. The highest frequency of negative response demonstrated poor ergonomic status and vice versa.
Results: The results revealed that the maximum average negative score among the six principal evaluation criteria was related to the information and communication index at an average score of 66. The other criteria were ranked as follows: the management, staff, equipment design, environment layout, and job characteristics with average scores of 58, 56, 54.67, 49.5, and 36.8, respectively.
Conclusion: The ergonomics culture questionnaire was prepared and analyzed by an expert team using the Delphi method. According to the indices, the ergonomics culture level was unacceptable at the North Tehran Health Center. Thus, it is recommended to provide ergonomics courses and seminars, video clips, pamphlets, posters, and related courses. Also, training and development of ergonomics instructions can help establish an ergonomics culture in the organization to a significant extent.