Journal of Health and Safety at Work

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Introduction: Work conditions in kerbside ticket booths intensify the risk of health threats. In this research, it is aimed to introduce solutions for improving ergonomics conditions of these booths, by ranking and analysis the risk factors.

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Material and Method: Demographic information as well as physical, mental, and safety conditions of 47 booths are collected through questionnaires, interview and video recording. Following, critical index was identified using a hybrid method including QEC checklist, ANOVA statistical test and innovative methods for determining ergonomic indices. Improvement strategiesfor the critical index were analysed,using CATIA V5 R20 software and RULA technique, and solutions were presented.

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Result: Based on F-test at the 0.05 significance level, anthropometric characteristics and personal informationshowed no difference betweenmale and female vendors, except for weight. Comparison of ergonomic indices manifested the maximum occupational exposurefor physical-motor factors (45.39) and environmental factors (41.28). Additionally, the highest risks determined by Nordic questionnaire and QEC checklists belonged to arms and shoulders (38) and wrist (26). Three dimensional model of vender with current and suggested postures were analysed using RULA and accordingly it was found that risk levels were improved for right and left side of the vendor body from 7 and 5 to 3 and 1, and for customers from 6 to 1.

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Conclusion: Vendors of electronic ticket booths are exposed to musculoskeletal and environmental health threats, in Mashhad. Relocating the booths, adjustingcounterand desk height can significantly reduce the risk of mentioned hazards

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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: A high percentage of musculoskeletal disorders in workplaces occur due to awkward posture and non-ergonomic design of the work stations for lifting and carrying of materials. To avoid these injuries, jobs should be designed in a way that ergonomics risk factors are controlled properly. The aim of this study was to utilize ergonomics interventions to minimize ergonomics risk factors in bag packing unit in a mineral processing plant.

Material and Method: This cross sectional study was carried out among 20 workers of bag packing unit. Camera recording of working postures, evaluation of medical records, interview, and REBA technique were used to identify the ergonomic risk factors. Interventions included changing the conveyor belt height and the use of spring pallets (spring table). Data were analyzed using Paired T-Test by SPSS software version 18.

Result: Before implementing ergonomics intervention, a total of 75% of evaluated postures by REBA technique obtained score of 8-10 (very high risk level) and 25% had score of 11-15 (very high risk level) that correspond to the action level 3 and 4, respectively. Following the implementation of ergonomics interventions, a total of 90% of the analyzed postures showed action level 2 (moderate risk level) and the remainder 10 percent of evaluated postures showed high risk level. Comparison of REBA technique scores before and after implementing interventions showed a significant difference (P-value < 0.05).

Conclusion: Based on the findings of this study, the implementation of ergonomics interventions has remarkably decreased the required action level and it may be able to improve work-related postures.

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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: Nursing is one of professions that employees are at risk of fatigue and work related musculoskeletal disorders, because of high physical workload and high job stress. Connecting serum set to serum solution is one of the repetitive tasks for nurses in their working times and it may cause pain and discomfort in their hand. The aim of this study was to design and ergonomic evaluation of a tool for connecting serum set to serum solution.

Material and Method: This experimental- interventional study conducted on 12 nurses (6 men and 6 women) in 3 phases. First phase was assessment of manual connecting of serum set to the bag by nurses, second phase was design and manufacturing of serum set connector and third was ergonomic assessment of the manufactured tool. In first and third phases, amount of perceived exertion by nurses was assessed using the Burg scale (CR10), and electromyography assessment for hand muscles activity was conducted during connecting serum set. Data of first and third phases compared with statistical tests.

Result: Mean score of perceived effort during manual connection of serum set was 5±1/2 (of 10) and while mechanical connection with designed tool was 2.3±0/49. There was significant difference between activity in 5 muscles (Flexor Digit Comonis, Flexor Carpi Radial, Biceps, Triceps and Deltoid) in manually and mechanically connection mode (P-value<0.05).

Conclusion: Use of serum set connector reduced the perceived effort and activity of hand and wrist muscles. This device can be used as an ergonomic tool for nurses to easing the inserting the serum set to serum solution

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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: Occupational health is one of the important issues that can affect productivity and economic development of an organization. This study aimed to determine the effect of didactic interventional Ergonomic-Safety program on workers’ productivity of an assembling industry.
Methods and Materials: This interventional study was conducted on 54 workers of assembling part of an electronic industry. Firstly, QEC method was used for Ergonomic assessment of work place and Hersey-Goldsmith questionnaire was applied for assessment of productivity. Then a comprehensive program was provided using findings of first stage assessment and identifying of existing failures. Second assessment of Ergonomic condition and productivity was done again by using QEC method and Hersey-Goldsmith questionnaire within three month of interventions. Data was analyzed by using of R software.
Results: Mean total productivity score and mean whole body score of QEC were 75.24 and 99.40 in before intervention phase respectively. In after intervention phase, Mean total productivity score and mean whole body score of QEC were 80.16 and 97.92 respectively. Data analysis by paired-samples t-test shows that difference of productivity score in before and after intervention phase was significant (P-value˂0.05). But difference of whole body score of QEC score in before and after intervention phase was not significant (P-value>0.05).
Conclusion: Accomplishment of Ergonomic-Safety intervention had a positive effect on productivity score whereas had not significant effect on general condition of body limbs.

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Introduction: The carpet industry is one of the most important handicrafts in Iran. This industry is one of the most difficult and harmful professions, in which the employees are often working in a workplace with non-ergonomic, unsafe, and unhealthy conditions. The present study aimed to address the modeling of the individual, job characteristics, and workplace conditions with the general health of carpet weavers through an ergonomic approach.
Material and Methods: The current study was a descriptive-analytic survey. The study population was female workers, who have had a minimum of one-year work experience and working in the workshops located in Meshginshahr city villages. The data collection tool was a combination questionnaire including, Goldberg’s questionnaire (GHQ-28), NIOSH questionnaire (disease history section), and questions about workplace conditions. The obtained data were entered into SPSS-17 software and analyzed statistically using statistical modeling based on the general linear model, multivariate and other statistical tests.
Results: Unpleasant condition was observed among the 37.4% of the examined, in terms of general health. Logistic regression modeling was used to investigate the internal and external factors of carpet weavers with their general health status. According to the model, general health has a significant relationship (p<0.05) with most of the internal factors such as age, marital status, history of disease, etc. However, there was no significant relationship with the workplace conditions.
Conclusion: According to the results of this study, it can be concluded that demographic and job variables are of the most important factors affecting the general health of carpet weavers. Although in the model, the workplace conditions did not show any significant relationship with the components of general health, interpreting these findings requires more studies. More studies are required objectively to identify the effect causes of the general health of carpet weavers (especially workplace conditions).

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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.

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Introduction: Complex sociotechnical systems, such as automotive industry, require a proper macro-ergonomic approach to design and implement the work system at micro-ergonomic level. The purpose of this study was to develop and validate effective macroeconomic factors to improve productivity, health and safety of employees in the automotive industry based on Holden & Karsh model.
Material and Methods: At the first step, relevant documents were reviewed, and then experts were interviewed to identify macro-ergonomic factors. The identified factors were categorized into four groups based on Holden & Karsh’s model. In the follow-up phase of the study, then, the content validity of the factors was calculated using Delphi technique in the form of an expert panel. Finally, validity acceptance was assessed using mean content validity index, and agreement between experts was evaluated using modified kappa coefficient
Results: 28 main factors were identified and categorized into four subgroups, including personnel, unit /department, organization and environment factors. 19 main factors were selected as the effective macro-ergonomic factors to improve employee’s productivity, health, and safety. The content validity index and the modified kappa coefficient were calculated as 0.901 and 0.90, respectively.
Conclusion: Macro-ergonomic factors identified in this study can be considered to improve employee’s productivity, health, and safety in the automotive industry. These factors can be used as specific context-based criteria for an ergonomic evaluation in the automotive industry, or even be generalized to other industries, organizations and companies.

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Introduction: The design of traffic signs should consider human cognitive abilities to enhance drivers’ understanding of the signs. Cognitive features, as one of the crucial principles of ergonomics, are among the influential factors in the design of signs. The present study aimed to evaluate the effect of graphic elements of eight new sign designs based on cognitive features on conveying the message “prohibition of using mobile phones.”
Material and Methods: This study was conducted in six driving schools in Tehran in 2013. One hundred seventy-four participants, with an average age of 23.5 and a standard deviation of six years, participated in this study. Participants were then presented with the designed signs through a colored questionnaire. They were instructed to evaluate the signs’ cognitive features including simplicity, concreteness, meaningfulness, and semantic closeness—using a Likert scale ranging from 0 to 100. 
Results: The results revealed that the average score of the cognitive features of the designed signs is higher than other traffic, industrial and pharmaceutical signs. In this study, “semantic closeness” was the best cognitive feature for predicting the message of the signs. The sign with the “hands-free” element had the best performance in transferring the message.
Conclusion: This research aimed to identify the most effective of eight proposed signs for banning mobile phone use while driving. Participants rated the sign featuring a button phone with a hands-free symbol as the top choice. Although most of the mobile phones in the market are of the touch screen type and the use of button phones has decreased a lot, the symbol of these phones as the dominant symbol still effectively conveys messages.
 

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Introduction: In all societies, tools and equipment are generally designed for right-handed people, who make up approximately 90% of the population, but left-handed and ambidextrous people (those who use both hands in manual activities) also live among us. Even in delicate and sensitive jobs. This research investigated the relationship between the spectral effect of the dominant hand and grip strength and hand dexterity.
Material and Methods: A cross-sectional study was designed to measure the power and precision grip of 182 adult participants (56% female and 44% male). The dominant hand of the participants was determined using the Edinburgh Dominant Hand Questionnaire. Power grip strength was measured using the Constant 14192-709E. Pinch grip test was performed using Saehan Hydraulic Pinch Gauge SH5005 for both hands separately. Dexterity of both hands was also measured using the Pegboard 32020A tool.
Results: Power and precision grips were more common in men than in women (P<0.001). Power grip differed between right- and left-handed women (P=0.019), with right-handed women having greater grip strength. The Precision grip of left-handed men was significantly (P<0.001) greater than that of right-handed men. Hand dexterity of left-handed men was significantly (P<0.001) higher than that of right-handed men. Two-handed agility (P<0.001) and assembly dexterity (P<0.001) are significantly higher in ambidextrous people than in right- and left-handed people.
Conclusion: The power, precision grip and dexterity are different between women and men. The grip strength of men is stronger than that of women. Ambidextrous people have more dexterity and assembly agility, so in jobs that require the use of two hands, they perform better and will be recommended for employment in this category of jobs. 

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Introduction: Scientometrics is a research field that examines and analyzes scientific trends and patterns in various scientific journals. This study aims to analyze the content of research published between 2011 and 2022 in Persian scientific journals focusing on ergonomics, to identify trends and the scientific direction in the field. 
Material and Methods: This study collected all articles published from 2011 to 2022 in Persian journals, including “Occupational Health,” “Occupational Health and Safety,” “Occupational Health Engineering,” “Iranian Journal of Ergonomics,” “Occupational Medicine,” and “Occupational Hygiene and Health Promotion,” using a census method from the journals’ websites. 368 articles were categorized based on thematic codes developed by experts, and data were analyzed using Excel 2010.
Results: The theme “Physiological Status and Occupational Factors” had the highest frequency (17.65%), while “Ergonomics in Small Workplaces and Services” had the lowest (0%). Approximately 55% of the published studies were centered around themes including “Physiological Status and Occupational Factors,” “Ergonomics Methodology, Methods and Techniques,” “Inspection, Monitoring, and Evaluation of Performance,” and “Characteristics of Physiology and Cognitive Processes.” The research focus in ergonomics tends to prioritize methodology and innovation over the practical application, emphasizing industrial needs over those in services and agriculture, and favoring large workplaces over small or construction sites.
Conclusion: The thematic framework and publication patterns can serve as valuable sources of information for educational and research planning within the field of ergonomics for universities, research centers, and related organizations; it can contribute to the scientific advancement of the field and lead to its overall improvement.