Journal of Health and Safety at Work

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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.