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Introduction: The purpose of occupational health is to maintain and improve the health of employees and improve their physical, mental and social well-being through the prevention, control and elimination of occupational hazards. It is necessary to integrate educational, research and health service activities to prevent and control potential occupational health hazards in the community. This study aimed to develop a Joint Comprehensive Plan Of Action (JCPOA) for occupational health at Tehran University of Medical Sciences (TUMS). Material and Methods: In this participatory action research, a strategic planning committee was established, whose members were professors of the occupational health department in the school of public health and managers of the occupational health department in the health deputy of TUMS. The strategic planning committee carried out a strategic evaluation of the internal and external environments of both occupational health deprtments of TUMS and identified the strengths, weaknesses, opportunities and threats. Then, the strategic direction of JCPOA including the vision, mission, values, goals and objectives was determined. Also, the strategies and actions to achieve the goals and objectives were identified. Finally, the action plan to achieve these objectives was developed. Results: This applied research led to the strategic evaluation of the internal and external environments of the occupational health depratment of the School of Public Health and the occupational health depratment of the Health deputy of TUMS, determining the strategic direction, and finally, developing an action plan to achieve the goals and objectives. Conclusion: The JCPOA for occupational health was developed using a collaborative and systemic approach. The proper implementation of this plan can lead to the improvement of occupational health indicators in the community. Cooperation between university and industry is necessary for the sustainable development of society.

Introduction: Strategic management involves determining the organization’s direction, preparing a strategic vision and mission statement, and providing the basis for growth, profitability, and production. It also includes the inclusion of employee safety and health programs throughout the organization. The existence of a strategic plan for the scientific and practical strengthening of occupational health and safety is one of the country’s academic and industrial priorities. The purpose of this study is to present a strategic plan for developing the specialized field of occupational health and safety engineering in Iran. Material and Methods: The current study is a collaborative action research study that was conducted in 2021. The strategic planning committee consisted of 20 professors, experts, and doctoral students. Over the course of 14 weeks, they held regular weekly meetings, collected information from inside and outside the organization, analyzed the organization’s internal and external environment, and identified its strengths, weaknesses, opportunities, and threats. Based on this analysis, the committee determined the organization’s mission, perspective, values, and general and specific goals for 2021-2024. They also identified the necessary measures to achieve these goals and developed an operational plan to improve the performance of the specialized field of occupational health and safety. Results: Conducting this applied research led to the strategy of internal and external analysis of the specialized OHS field, determining the direction of the basic strategy, mission, perspective, values, and general goals. Finally, seven specific goals and 286 actions were determined to improve the performance of OHS. The SWOT analysis of OHS’s internal and external environment identified 27 strengths, seven weaknesses, 26 opportunities, and 12 threats. According to the results of the SWOT matrix, the strategic position of the OHS field is to implement preventive strategies and maintain existing conditions. Conclusion: This plan aligns with the 4-year OHS plan. In developing the program, attention has been paid to the documents and policies of upstream organizations. The strategic position of occupational health and safety engineering is a prudent strategy. In this situation, strategies for maintaining existing conditions can be applied. Therefore, it is suggested to reduce the weaknesses of OHS as much as possible and increase its strategic capabilities by focusing on prudent strategies. From the second year of implementing the strategic plan, the OHS field can gradually focus on developing activities.

Introduction: Air traffic control is a very complex process, including multiple human-machine interactions. Human mental workload plays an important role in this process. Nowadays, electroencephalography indexes are considered as new indicators in the field of assessment of mental workload. The purpose of the present study was to investigate the relationship between EEG theta power and mental workload in air traffic control simulation. Material and Methods: Fourteen air traffic controllers participated in this study. Controllers carried out two scenarios, including low and high workload, based on task load factors in an air traffic control simulator. Mental workload was assessed in these two scenarios by the NASA-TLX questionnaire. EEG signals were continuously recorded during air traffic control tasks. Afterward, absolute theta power was extracted from participants’ EEG using Fast Fourier Transform (FFT) by the MATLAB software and was compared with each other in terms of high and low workload. Results: The results showed a significant relationship in absolute theta power during low and high workload scenarios in all regions of the brain (p < 0.05). Absolute theta power increased primarily in the frontal region during the high workload scenario. Also, there was a significant increase in the relationship between work experience and absolute theta power at the F3 region during the high workload scenario (P=0.021, r=0.607). Conclusion: Absolute theta power provides a good parameter to assess mental workload at different levels of air traffic control tasks. Therefore, it can be used as a tool for the design of human-machine complex systems.

Introduction: Compared to other hospital departments, emergency department (ED) nurses experience higher levels of occupational fatigue. However, despite the importance of fatigue in EDs, limited studies have investigated the issue. Therefore, the present study aimed to identify factors affecting ED nurses’ fatigue with a systemic approach and provide a comprehensive model of fatigue. Material and Methods: The present study was the first phase of a mixed-methods study with an exploratory sequential design that was conducted qualitatively. Data was collected using a semi-structured interview technique among ED nurses in TUMS hospitals in Tehran. The data was analyzed with a systematic approach and qualitative content analysis method. To check the credibility and trustworthiness of the study results, Goba and Lincoln criteria, including transferability, peer review, and member check, were used. Results: Extensive factors were identified in the four levels of nurses’ work system, including individual factors, work unit, organization, and extra-hospital factors that could facilitate or prevent nurse fatigue. Specifically, the categories that were mentioned the most by the nurses were aggression and conflict with visitors, ED workload, understaffing, crowding and noise, obligatory overtime, acknowledgement, visitor’s expectations, reporting (paperwork), and clients’ distrust of nurses. Finally, based on the qualitative results, a conceptual model of factors affecting occupational fatigue of ED nurses in Tehran was presented. Conclusion: Traditionally, fatigue management programs in hospitals only consider issues related to work shifts and sleep hygiene. However, the results of the present study revealed other fatiguing factors in the work system of ED nurses. These findings can help health system decision makers and HFE experts in designing effective fatigue risk management systems in Iranian hospitals, especially in emergency departments.

Introduction: Given the high prevalence of low back pain in manual handling activities, its known relationship with spinal loads, and the role of muscular fatigue and the body’s adaptive mechanisms to counteract fatigue, this study investigated the effect of repetitive lifting tasks on trunk muscular fatigue and the kinematics of the spine and load-in-hand. Material and Methods: Eighteen male volunteers lifted a box from the floor to their waist height at a pace of ten lifts per minute until they could no longer continue the task and reported the highest level of exhaustion. Kinematic data and muscle electromyographic activity were simultaneously recorded using a motion capture system and an electromyography device. In this study, average trunk flexion angle and trunk angular velocity were calculated as trunk kinematic variables, while average box vertical travel distance, average box horizontal displacement from L5-S1, and average box vertical displacement velocity were considered as box kinematic variables. The median frequency of electromyographic signals from selected muscles was quantified as a muscle fatigue indicator. Since subjects performed different lifting cycles, the total number of cycles was divided into five distinct blocks for data analysis. Results: The results showed significant effects of lifting trial blocks on trunk angle (p=0.004) and vertical box displacement (p

Introduction: Universities play a key role in creating a knowledge-based society and its sustainable development. Strategic planning by strategically analyses internal and external environments of the organization, forecast its future, identifying its strategic direction, and strengthening organizational structures, processes, and outcomes, creates and sustains competitive advantages. This study aimed to formulate a strategic plan for the Occupational Health Engineering (OHE) department of School of Public Health (SPH) at Tehran University of Medical Sciences (TUMS). Material and Methods: In this participatory action research, a strategic planning committee was formed. The strategic planning committee used the strength, weakness, opportunity and threat (SWOT) matrix to evaluate the internal and external environments of the OHE department. Then, the mission, vision, values, goals and objectives of the OHE department were defined. Finally, the operational plan including actions to achieve the goals and objectives were formulated. Results: Experienced professors and staff, specialized laboratories, professional journals, and high ranked postgraduate students were the most important strengths; and theoretical and non-practical courses, lack of educational protocols, poor communication with industries, lack of resources, and low motivation of employees were some of the weaknesses of the OHE department. The support of senior managers of TUMS, industry liaison council at school and university, facilities of the university faculties, comprehensive research laboratories of the university, capacities of the private sector and increasing the demand for research in the industry were the opportunities. High inflation, political sanctions, the absence of consulting engineering companies and the uncertainty of research priorities of industries were important threats to the OHE department. Therefore, the OHE department is in a conservative strategic position. The strategic direction of the department, including the mission, vision, values and goals, until 2025 was determined. Improving the structures, working processes and performance of the occupational health department were determined as objectives and 81 actions were formulated to achieve these objectives. Conclusion: The educational departments, schools and universities must have a strategic plan for progress. The strategic plan of the occupational health department of TUMS was formulated in line with the four-year plan of the university and coordinated with the operational plans of the educational, health and research deputies of TUMS and school of public Health. Proper implementation of this comprehensive and evidence-based strategic plan will improve the performance of the occupational health department.

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.

Introduction: Human factor analysis has been identified as the most common cause of accidents in natural gas transportation and distribution facilities. The occurrence of accidents at these systems, especially gas reduction stations located in residential and industrial areas, has had catastrophic consequences. Therefore, this study aimed at analyzing critical tasks and human error assessment using the system for predictive error analysis and reduction (SPEAR) method and providing the appropriate framework for error management in the operation and maintenance of city gate stations. Material and Methods: This descriptive cross-sectional study was conducted using the SPEAR framework and safety critical task analysis guideline to evaluate errors in gas pressure reduction stations. First, critical tasks were screened and evaluated, followed by performing task analysis by the hierarchical task analysis and detecting performance-influencing factors (PIF). Then, human errors were predicted and assessed based on the predictive human error analysis. Finally, error management was developed at three process, equipment, and training improvement levels. Results: In general, out of 23 operations and 164 sub-tasks, 12 critical tasks were identified based on the results. Criticality level percentages were about 67% high risk, 25% moderate, and 8% low risk. In addition, 134 errors were identified which were mostly related to action (42.53%) and checking (39.55%) errors, respectively. Eventually, communication, retrieval, and selection errors were 8.96, 5.22, and 3.74%, respectively. Conclusion: The results revealed that action and checking errors had the highest percentages. This method can be applied to appropriate the systems approach to error reduction using the PIF assessment output. The privilege affecting factors include preparing standard operation procedures, implementing a comprehensive training program, and controlling environmental hazards.

Introduction: The use of exoskeletons as a new ergonomics intervention to reduce musculoskeletal disorders risk factors and increase human performance has emerged in the fourth-generation industrial revolution. The aim of this study was to assess the cervical exoskeleton effect on the neck and shoulder muscles electrical activity. Material and Methods: In this experimental study, 14 male participants were asked to perform the simulated overhead work with and without using the cervical exoskeleton at two neck postural angles randomly. During the task, electromyography of the target muscles in the neck and shoulders was recorded. In addition, at the end of each task, participants completed a perceived discomfort questionnaire. Electromyographic signals were processed with Matlab 2017b software and the level of the electrical activity of the target muscles was normalized to the maximum muscle activity. Data analysis was performed using Random intercept mix model in STATA 14 software. Results: Mean perceived discomfort in the neck and shoulders regions significantly reduced by the exoskeleton device, but there was no statistically significant difference in other areas. Also, the mean activity level of sternocleidomastoid and splenius capitis muscles on the right and left was significantly decreased during the use of the cervical exoskeleton. However, this difference showed a significant increase in trapezius muscles. Conclusion: The use of the neck exoskeleton was associated with a reduction of muscle electrical activity and the perceived discomfort in the neck area. These results may be related to transferring neck and head weight by the exoskeleton retaining jack during the neck extension to other areas of the body. The exoskeleton design did not provide support for the shoulder and arm area, which explains the reason for the non-significant results in the shoulder area. Using the exoskeleton with the additional support in shoulder area could be considered as an ergonomic intervention in such overhead works.

Introduction: Nowadays, excessive computer use in the workplace has raised concerns about the health status of VDT workers, particularly complaints about eye discomforts. Due to the importance of the eyelids and eye closure parameters on eye health during computer works and the direct effect of monitor height on these parameters, this study was aimed to examine the effect of different monitor heights adjustment on the eye indicators and eye discomfort among participants. Material and Methods: In this study, any changes in the eye indicators including blink rate, the eye blink opening and closing time, the blink opening rate in three different monitor heights (standard, low, and high) were examined among 11 participants. The blink rate and the eye blink opening and closing time were measured and evaluated using videotaping and analyzing by an image processing software, developed in this study. Participants were also asked to complete a questionnaire for eye fatigue assessment due to daily computer uses. Results: Results showed that the highest rate of eye blink was at the standard height of the monitor, and this rate was significantly different at three different heights of monitors (high, standard, and low) (p

Introduction: The noise could affect some aspects of human health, including the cognitive performance. In addition to sound pressure level and exposure time, the psychoacoustic features of noise may cause destructive effects on humans. A few recent studies have been conducted on effect of sound quality on cognitive performance. This study aims to find the noise loudness and sharpness levels as the most destructive effects on human cognitive performance. Material and Methods: This was a cross-sectional study on 10 male students of Tehran University of Medical Sciences. The Noises were generated in two channels that the left channel produced the pink noise as a background noise. The pink noise loudness and sharpness were 19.7 sone and 2.49 acum, respectively. The right channel generated noises with different loudness and sharpness levels the noise loudness ranged from 8.87 to 67.9 sone and the noise sharpness ranged from 1.07 to 6.4 acum. Finally, ten noises with different loudness and sharpness were applied. The students were exposed to ten different types of noise and a silent condition. The Mathematical Problem Solving Task (MPST) test was performed to assess cognitive performance. The reaction time and the accuracy rate were measured after 5 minutes of noise exposure. Data were analyzed by SPSS (ver. 22). P< 0.05 was considered as significant level. Results: The mean reaction time and the mean accuracy rate increased with the sharpness level. However, alteration in the loudness and sharpness levels had no significant effect on the speed and accuracy of students. Performance speed increased in noise 3 with the highest loudness (L=67.9, SH=1.07) in comparison with the silent condition (p-value=0.05). The mean accuracy rate in exposure to the noise 9 reduced in comparison with silence (p-value=0.04) Conclusion: Different levels of psychoacoustic features had no significant effect on the cognitive performance parameters. Although, the accuracy rate and the reaction time decreased in noises 9, the sharpest noise, and 3, the loudest noise, in comparison to the silence, respectively.

Introduction: Musculoskeletal disorders (MSDs) are prevalent in work settings and are associated with high rate of prevalence and costs. Musculoskeletal conditions have multifaceted nature, and occupational factors play an important role in their development. The aim of this study was to identify the risk factors of work-related musculoskeletal disorders in the working population in Iran during 2000 to 2015. Material and Methods: Using the appropriate search terms, articles published in the journals, student thesis, and those presented at the conferences were searched through authentic English databases (Google Scholar, Scopus, PubMed) and Farsi ones (Magiran, SID, IranMedex, Irandoc). Following removal of duplicate citations and irrelevant studies, the full texts of the remaining publications were prepared and assessed for more detail. Results: Perceived discomfort in low back region obtained the highest score in workers of industrial, administrative, service, and agricultural settings. However, in the handicraft and educational groups, the highest percentage of discomfort was belonged to neck (66.7%). Findings showed that the most commonly used techniques for evaluation of musculoskeletal disorders and risk factors were, respectively, Nordic questionnaire (NMQ) (76%) and REBA (13.9%). Moreover, all identified risk factors were classified into eleven groups including: biomechanical, work environment design, tools, equipment, temporal aspects of job design, job content, organizational aspects, economic and financial issues, social aspects, individual characteristics, and training. Conclusion: Overall, a wide range of risk factors reported in the previous studies were categorized in the present review. The results are suggested to be considered by managers and decision makers as a framework to take measures for controlling musculoskeletal disorders to accomplish the goal of ergonomics, which is productivity and well-being.

Introduction: Designing behavioral modification interventions for the use of personal protective equipment (PPE) warrants the audiences identification and analysis. This study aimed to determine the predictive factors for using (PPE) based on Social Cognitive Theory (SCT) constructs among workers of Iran Aluminum Factory, 2018. Material and Methods: In this descriptive analytical study with cross-sectional method, a researcher-made questionnaire including demographic information, knowledge questionnaire and designed items based on the SCT construct, was fulfilled by 188 workers employed in production line of Iran Aluminum Factory in Arak. The collected data was analyzed using descriptive statistics, Chi-square and logistic regression analysis on SPSS 24. The significance level was set at P< 0.05. Results: Among the participants, 46.8% (n=88) and 52.2% (n=100) of workers had moderate and high level of knowledge, respectively. Demographic variables such as marital status, educational level, income, age, work experience and employment status (p

Introduction: Workers in car manufacturing industry are at risk of a high prevalence of musculoskeletal disorders, especially low back pain. Therefore, in the present study aimed to design and fabricate a portable device to evaluate the low back kinematics and to compare these variables in workers with and without low back pain (LBP) in assembly lines of an automotive industry. Material and Methods: In the present research workers postures were assessed using OWAS direct observational method. Moreover, simultaneously, prevalence and intensity of low back pain were evaluated by Dutch Musculoskeletal Questionnaire (DMQ) and Visual Analogue Scale (VAS). After fabricating motion analysis device, a field study was conducted using the designed device among 16 volunteers to investigate low back kinematic variables in two groups of workers: LBP and non-LBP. Results: The results showed that 62.1 percent of all working postures were high risk with corrective action levels of 3 and 4. On average, 86.1 percent of workers experienced LBP in the previous 12 months. Regarding comparison of kinematic variable in the two groups of LBP and non-LBP, workers without LBP had higher degree and duration (in second) of movements (forward flexion, lateral bending, extension, and twisting), as compared to those with LBP. However, only movement range of forward flexion in non-LBP group (mean: 64.29 and SD: 8.41), was significantly higher than those with LBP (mean: 58.97 and SD: 11.34). Conclusion: The device can be used as an effective tool in the ergonomics studies in the field of back pain, due to its potential to record the kinematics of the trunk, as well as its lightweight and non-interference with the task. Device’s validity was acceptable based on the comparison of the results of this device with those obtained from inclinometer.

Despite the unprecedented mobilization of people and resources to confront the COVID-19 Phenomenon, the identification and treatment of ever-increasing number of patients has put the health systems of many countries under an unprecedented pressure beyond their capacity. On the frontline of this battle, the employees of the health systems, especially nurses are among the people who have been impacted the most by this natural disaster. This editorial aims to have a comprehensive look at the various dimensions of the barriers and problems that nurses have faced during the pandemic. Based on investigations, early into the pandemic, shortage of preventive and diagnosis equipment, as well as low usability of personal protective equipment were the most important challenge of nursing. Nursing job characteristics have also undergone a major transformation by an adverse increase in the physical and mental workload of the profession. Moreover, nurses’ working condition has been so inevitably affected by the phenomenon’s characteristics of fear and uncertainty. This unprecedented situation has also hindered the hospitals in providing an appropriate physical environment for their patients and employees. On the other hand, in spite of having great importance, scant attention have been paid to organizational (i.e., shortage of specialized workforce, lack of training for new nurses, and inefficiency of break time) and extra-organizational (i.e., sanctions and stigma) issues. Lastly, the consequence of such difficult and grueling conditions has been various psychosomatic disorders which can be a serious threat not only to nurses’ health and quality of care, but also to the proper functioning of the health systems of countries.

Introduction: Assessing health, safety, and environment (HSE) performance based on up-to-date analytical models like resilience engineering, especially in automobile manufacturing companies, affected by the trilogy of HSE factors and functions, is of crucial importance. Therefore, this study was to review the factors effectively involved in HSE management performance assessment based on resilience engineering in automobile manufacturing industries. Material and Methods: To collect and classify the data, many relevant articles and procedures published in journals or presented at seminars were researched and cited. In this study, reliable online databases, including Google Scholar, Web of Science, Scopus, and PubMed were searched to meet this purpose. Other databases in Farsi such as Magiran, CIVILICA, and Scientific Information Database (SID) were also employed. Accordingly, a total number of 211 articles were extracted and filtered in terms of content and topic by a team of four HSE senior experts, whereby irrelevant studies were deleted, the full text of each relevant article was more closely considered, and finally 18 studies were selected and thoroughly examined. Results: The findings from these 18 articles revealed that the HSE would be influenced in various industries by factors such as organizational culture, learning and training, political-economic variables, workforce qualifications and skills, strategic and large-scale programs of organization plus its assets and financial resources. In automobile manufacturing industries as well, circumstances might emerge because of some extra-organizational threats and intra-organizational weaknesses, whereby the appearance of deficiencies in various processes and even the functions of the HSE as a whole would be impaired. Of the many external factors, one could mention economic sanctions, large-scale socioeconomic problems, and lack of materials and production equipment. The internal problems would also range from production reduction and cuts in budgets earmarked for different management departments to a rise in the number of accidents and diseases, soaring medical treatment costs, as well as growing expectations in employees, which together impact the HSE management performance. Conclusion: Regarding the studies conducted on various models presented so far in the area of resilience, it was concluded that the HSE performance of organizations intended to prevent and control risk factors were by no means distinct from other management factors and strategic decision-making in an organization. Rather, the HSE indicators could be impacted by many extra- and intra-organizational factors. Based on the models surveyed, it would be essential to consider the concept of resilience in HSE management. The reason for this is that the idea of the HSE would appear to be an issue of less virtue and importance in various stages and situations in the lifecycle of an organization, which is not consistent with the HSE management system and does not keep pace with the influencing factors.

Introduction: Workload can be defined as the hypothetical construct that represents the cost incurred by a human operator to achieve a particular level of performance. Several methods have been used to assess the workload. One of the most common methods of assessing mental workload is NASA-TLX method. The present study was conducted to develop and validate of a pilot activity load index (PALI) based on NASA-TLX template. Materials and Methods: This study was a cross-sectional and descriptive-analytical that was carried out among airline pilots of Civil Aviation Organization. At first, “Pilot Activity Load Index” or PALI subscales were developed based on NASA-TLX template. Validity of the subscales was evaluated by Content Validity Ratio (CVR) and Content Validity Index (CVI).Using Lawshe’s table. Finally, to determine the internal consistency of the subscales, 30 pilots completed the final version of the PALI in typical flight phases. The data obtained were then analyzed by SPSS using Cronbach's alpha to measure the reliability of the subscales and considering an acceptance level of 0.7. Results: The first results led to the emergence of an initial list with 17 subscales. Eleven subscales were irrelevant, redundant and impractical to use in operational environment, due to CVR less than 0.75 and were omitted from the subscales list. Finally, six PALI subscales were approved related to pilot tasks (CVI=0.79). The Verified subscales had a Cronbach's alpha value of 0.89 and were therefore considered a reliable tool. Conclusion: The results of this study showed that PALI questionnaire which validity and reliability has been approved can be used for assessment of workload in pilots.

BACKGROUND: The National Institutes of Health (NIH) developed a new measurement system called the Patient-Reported Outcomes Measurement Information System (PROMIS) which can be used for multiple health conditions. The 29-item short form (PROMIS-29) with seven domains was more often used by clinical researchers to measure the physical function, mood and sleeping status of patients with low back pain (LBP). Translation of the PROMIS into multiple languages and adaptation of its application in different cultural diversities can help to further standardize clinical research studies and make them comparable to each other. This study aimed to cross-culturally adapt the PROMIS-29 into Persian (P-PROMIS-29) and evaluate the construct validity and reliability of the translated questionnaire among patients with lumbar canal stenosis. MATERIALS AND METHODS: The translation was conducted by using the multilingual translation methodology guideline. Construct validity, internal consistency, and test–retest reliability at a two-week interval for the P-PROMIS-29 were calculated. Construct validity was assessed by calculating correlations between the P-PROMIS-29 with Oswestry Disability Index (ODI) and Roland–Morris results. RESULTS: The study sample included 70 participants with lumbar canal stenosis. Internal consistencies were moderate to good with Cronbach's alpha ranging from 0.2 to 0.94. The test–retest reliability evaluation was excellent with intraclass correlation coefficients (ICCs) ranging from 0.885 to 0.986. Construct validity of different domains of P-PROMIS-29 were moderate to good, with Pearson's correlation coefficient results ranging from 0.223 to 0.749. CONCLUSION: Our results showed that P-PROMIS-29 is a valid and reliable measurement tool for evaluation of patients with lumbar canal stenosis.

Background: Industrial incidents are one of the major problems of todaychr('39')s societies. Studies in this field show that the main and most important cause of error occurrence is human factor. Therefore, the aim of this study was to identify and evaluate the risk of human error in the activities related to the operation of electrical installations of the Tehran Province Electricity Distribution Company. Methods: This study is a qualitative and cross-sectional research was conducted by direct observation of the activities and documents, interview. Tasks and subtasks were selected and analyzed using Hierarchical task Analysis, (HTA).The results were presented in the form of HTA. Finally, according to the instructions of SHERPA, the relevant worksheet was completed. Results: The analysis of SHERPA worksheets showed that a total of 3399 errors were detected for 759 tasks as 39.57% of them were action errors, 32.4% review type, 7.32% recovery type, 19.64% communication type and 1.80% were selective errors. According to the results of risk assessment, 12.47% of the errors were unacceptable risks level, 59.57% were undesirable, and 20.2% were acceptable risks but need to be revised and the rest, 7.33% acceptable with no need for revision or safe ones. Conclusion: According to the results, the most common type of error was action errors and in order to reduce this type of errors, using necessary corrective measures such as proper selection of people for occupations, training, monitoring, using smart machines, using tag out systems and checking at the suitable time and updating the instructions would be useful and effective countermeasures.

Nowadays, musculoskeletal disorders resulting from working with improper hand tools have been known as one of the major concerns in various industries. In the current study, an ergonomic nail removal device was proposed to evaluate the intervention for nail removal activity in the woodworking and carpentry industry. Eleven male workers, who were actively involved in nail removing activity, were asked to perform nailing activity by removing nails driven into the bottom and top of the door as the base points for painting the doors using both the nail removal device and the traditional plier. The Rapid Entire Body Assessment (REBA) and Strain Index (SI) techniques were used to characterize the level of risk. Moreover, nailing task duration and task repetition were measured as important criteria in manual works. According to the SI and REBA risk indices, the final scores for the designed device were estimated at 2 (low-risk level) and 1.5 (safe), respectively, while these values for the traditional pliers were 12 (high-risk level) and 15 (dangerous). Moreover, using the designed electric nail removal device led to a reduction in the repetition and duration of the task. Overall, the application of the proposed device in the nail removal tasks has shown risk indices below the critical thresholds in terms of correcting work posture and reducing strains imposed on workers' upper limbs.

Introduction: Nowadays, working in any computer work stations, named visual display terminal (VDT), was widespread and has become popular in our lives. Due to the increasing trend of using computers in the administrative and social institutions, prevalence of eye-related signs of working with computers is still increasing and it is one of the most important health issues. Computer jobs are low-mobility and require little energy to do physical work, but require more cognitive processing and mental focus. Visual fatigue is an occupational hazard for people working with computers. Eye fatigue has symptoms such as headaches, job discomfort, and eye pain the purpose of this study was to have a systematic review on eye fatigue, dry eye and eye blink among people working with visual terminals. Material and Methods: Internet search databases and search engines were used to find articles with focusing on the impact of risk factors on eye indexes on computer users. In this study, related articles were obtained from websites, including: PubMed, Google Scholar, Scopus and Web of Sciences. The keywords were used to search in these websites were: computer user, eye fatigue, dry eye and eye blink. Accordingly, after finding 115 relevant articles from the related sites, 17 articles were finally selected. Results: Findings show that using computer cause many problems in the eye. Duration of using the computer, the type of work with the computer, the mental load, the distance from the monitor, and also long-term use of the computer without break in during work can cause dry and fatigue eye in users, which is one of the most common ocular problems among computer users. Conclusion: According to the finding and results recommended to reduce of dry and fatigue eye, distance of users from the monitors, be more than 50cm, use 20-20-20 law to rest user’s eyes, and Positioning the monitor be 15-20 degrees below the user’s line of sight. Also, too much focus on the screen reduces blinking and resulting in dry eyes. In order to prevent dryness of the surface of the eye, it is recommended that the eyelid be optional even if possible. Increasing the contrast of the monitor can be helpful in reducing stress and strain on the eye while working with a computer and using glasses instead of lenses to correct refractive errors and one of the ways to control and improve dry eye is using artificial tears by computer users.

Background and aims: Anthropometry is the branch of human science that considers the physical measurement of the human body, especially size and shape. One application of anthropometrical data in ergonomics is the design of working space and the development of industrialized products. So that the tools, equipment and workstations, which designed based on the physical dimensions of the workers, can increase their productivity. According to statistics, 32% of workers possess awkward postures, and 15% of them use improper tools while working. These lead to increases the possibility of work-related injuries, particularly musculoskeletal disorders. Therefore, most countries have made great efforts to build own anthropometrics databases for various groups of citizens. Due to the lack of comprehensive databases in Iran, often it has been referred to information from the Western countries, especially the United States. The western nations have a big difference in anthropometric dimensions with the Iranian population, and their manufacturers also have been designing and developing tools and machines based on own mental criteria. The mismatching of these designed tools and workstations with the dimensions of the Iranian userchr('39')s body can cause complications such as fatigue or other physical damage. So, Iranian researchers have suggested that at least one comprehensive, up-to-date and general database needed from the population of the country. Consequently, the building of anthropometric databases is necessary. The results of several studies have shown that there is a correlation between the dimensions of the body with each other. These correlations can be used to create regression equations for estimating anthropometric dimensions. Identifying, categorizing, and determining the type of relationship between anthropometric dimensions play a significant role in treatment, fitness talent, and clothing production, etc. But, the relationship between these dimensions is affected by the environmental, economic and social factors change. The important affecting physical factors include age, sex, race, body structure, occupation, diet, and physical activity. Among these factors, the race has a very critical role in the variation of body size. So, the differences among diverse races are more than the variations between different nations. Ethnic diversity is a crucial factor that can affect anthropometric data and its application areas. For example, this variety in body dimensions between people with different sex and races can produce many problems in product design. Therefore, due to the necessity of having a comprehensive database (anthropometric data from different races) in the country, extracting appropriate information from massive data and transforming them into knowledge on one hand, and time-consuming and high expense process for collecting data on the other hand, especially in the Iranian population with many races, the use of modern methods is essential. Data mining is a new method used to extract useful and unknown information from raw data. Classification is a data mining function that assigns items in a collection to target categories or classes. The goal of classification is to accurately predict the target class for each case in the data. Decision Tree is one of the easiest and popular classification algorithms to understand and interpret. It can be utilized for both classification and regression kind of problem. It can also remove part of the consumed time and expense of collecting anthropometric data. Therefore, this study was intended to investigate and identify the most important factors of ethnic differences in anthropometric dimensions of Iranian workers using the decision tree. Methods: The present research is a methodological study using the classification systems in the field of data mining. The sample of the study was anthropometrics raw data (37 dimensions) of 3720 subjects (3,000 men and 720 women) from six races (Fars, Turks, Kurds, Lars, Baluch, and Arabs) of Iranian workers. The decision tree (DT) method was used to identify the most important factors of racial differences in anthropometric dimensions of Iranian workers. The WEKA software (version 3.6.12) was used to analyze data and implement data mining algorithms. In the case of the WEKA system, the data is extracted and translated into a standard format we call ARFF, (Attribute-Relation File Format). In the current study, the preprocessing operation on raw data performed by using a classification. Data preprocessing is one of the most critical steps in a data mining process which deals with the preparation and transformation of the initial dataset. Data preprocessing methods are divided into, data cleaning, data integration, data transformation, data reduction categories. Data cleaning routines work to clean the data by filling in missing values, smoothing noisy data, identifying or removing outliers, and resolving inconsistencies. Dirty data can cause confusion for the mining procedure, thus removing these data is a more appropriate method. For data preparation, first of all, missing data values identified by using statistical methods and then to replacing the lost data, the PLS Filter and Missing Class Values algorithms were used in the WEKA software. These algorithms first classify the data and compute the average value for each class and fill the missing data of each class with the mean value of that class. Distorted data also eliminated by using the Remove Useless algorithm. Later data preparation, Principal Components Analysis (PCA), one of the most used methods, implemented. It is a statistical procedure that uses an orthogonal transformation to convert a set of observations of possibly correlated variables (entities each of which takes on various numerical values) into a set of values of linearly uncorrelated variables called principal components. The primary motivation behind PCA is to reduce, or summarize, a large number of variables into a smaller number of derived variables that may be readily visualized in 2- or 3-dimensional space. The new set of variables created by PCA can be used in other analyses, but most commonly as a new set of axes on which to plot your multivariate data. After data preparation, the data are standardized and then the KMO factor is calculated. The KMO factor measure of sampling adequacy and compares the observed correlations and partial correlations among the original variables. The KMO increases with an increase of the number of variables and the correlation coefficients between them but does not much depend on the sample size. Specifically, correlation matrices with KMO< 0.5 are entirely inappropriate whereas those with KMO below 0.6–0.7 must be treated with caution. Then after the decision tree technique is applied. This technique is a tree-like structure that describes the set of rules that led to the decision, and the ease of interpretation is one of its most important features. This technique is used for categorization and is a graphical method for comparing alternative competition and assigning value to them by combining uncertainties, costs, and repayments by specific number values, which usually consists of several nodes called nodes Inputs and outputs are known. The rules created in the decision tree are also "if" and "then". In each node, you can also split more than two. The CHAID algorithm used to splits the target into two or more categories that are called the initial, or parent nodes. Results: for the analysis of the main factors, the 37 variables (anthropometric dimensions) converted to standard values. KMO value for the total data was 0.947. Since the obtained KMO (0.95) value was greater than the considered criterion (0.7). The existence of the necessary correlation between the input variables confirms the main factors analysis. The result of the analysis indicated, of the 37 anthropometric input variables, only 21 variables had a coefficient of above 0.7 in the seven extracted factors. The remaining 16 variables had little importance due to their high correlation with the main variables and excluded from the analysis cycle. In the decision tree, the race variable selected as the target variable or dependent variable, and its relation with 21 anthropometric variables examined. The optimal number of clusters obtained was 7 clusters. After entering and determining the type of data and dividing them into two sets: one with 70 percent of the source data, for training the model, and one with 30 percent of the source data, for testing the model. This default was chosen because a 70-30 ratio is often used in data mining. The results of the study disclosed that the distinctive factors in categorizing and creating ethnic differences among men were the Shoulder height in sitting position, the eye height in sitting position, the elbow- fingers length, bi-acromial breadth, the width of foot and length of the head, and among the women, Face Breadth, bi-acromial breadth and the length of the elbow-tip of the fingers. Conclusion: Identification of distinctive factors in the classification of racial differences is one of the main findings of the present research in various ethnic groups. According to the results of this study, these factors in Iranian women and men were different and regardless of race, the following conclusions are made; the distinguishing factors in men are related to anatomical factors (temple) and in women related to facial aesthetics (beauty). The results of this study also confirm the utility of using the decision tree method to investigate the interactions between predictor variables that can be identified the most important determinants of race by combining different nodes in the overall structure. The results from this study verified the using decision tree as an effective method of identifying important variables for classification and detection of racial differences in the anthropometric field. Furthermore, this finding could be used to designing optimal ergonomic workstations for Iranian workers with different Races, moreover to applications in the manufactures and design process, can be used in other cases such as forensic medicine for diagnosis and making orthopedic products.

Abstract Background: Usability is an index to assess a product from the viewpoint of users satisfaction, efficiency and productivity improvement. The main attributes of usability that are derived from the human factors are and used in usability design of the interfaces Include: compatibility, consistency, flexibility, minimal action, perceptual limitation, usefulness, learnability, ease of use, minimal memory load, user guidance, satisfaction and errors. The main aim of this study was to assess the usability of interface design tool for a ventilator utilized in the hospitals of Arak city, Iran; and study its validation and reliability. Methods and Materials After constructing the initial questionnaire from the standard sources, specific techniques to determine the validity, and Cronbachchr('39')s alpha coefficient were used for the validity and reliability study. The study procedure was: determining the scope and dimensions of the questions, drafting questionnaire, assigning members of the expert panel, study, questionnaire data acquisition and analysis methods, determining acceptance criteria of the questions and the content validity and reliability index. Results Final tool was a 42-items questionnaire. The content validity index (CVI) of questionnaire was 0.86. The results showed that the total Cronbachchr('39')s alpha coefficient was 0.89 as an acceptable value for the reliability of questionnaire. Conclusion After the final questionnaire design and the appropriate validity and reliability of it, adopting this tool to assess the usability of breathing apparatus (ventilator) is recommended. With usability assessment of such vital instruments, quality improvement, higher efficiency and productivity as well as errors reduction and good design user interface will be achieved.

Introduction: Previous studies confirm direct and indirect costs of low back pain in occupational settings. However, there is no systematic study of the risk factors for low back pain in different occupations; while planning and allocating resources requires comprehensive knowledge at the national and regional levels in order to control and manage low back pain. Therefore, the aim of this study was to identify risk factors of low back pain in Iranian workers during the years 2000 to 2015. Methods: Published journal papers, articles presented at the congresses and student thesis reports were systematically reviewed. Abstracts were extracted using appropriate keywords and authentic English-language (Google Scholar, Scopus, and PubMed) and Farsi (Magiran, SID, IranMedex, and Irandoc) databases. Following quality assessment of the selected publications, the full texts of the related ones were reviewed. Results: In 150 eligible studies, the mean prevalence of low back pain in the last 12 months was 48.77. Nordic questionnaire was the most commonly used technique for assessing back pain, and RULA and REBA were the most commonly used method for determining risk factors. All risk factors were categorized into nine groups: biomechanical, workplace design, tools and equipment, environmental, temporal aspects of job design, job content, organizational aspects, personal characteristics, and training. Conclusion: According to the findings, about half of the workers in Iran experienced low back pain. Considering the widespread risk factors and the high prevalence of low back pain among various occupational groups, it is suggested that appropriate measures be taken based on the findings of this study.

Nowadays, occupational related diseases and accidents are considered one of the main causes for mortality worldwide. However, Kiken Yochi Training (KYT) is one of the interventions to reduce the incidence of unsafe behaviors at workplace, yet there are few evidence-based studies on its effectiveness. This study was aimed to identify the unsafe behaviors among workers in the construction industry in Iran and determine the influence of Kiken Yochi Training intervention on their reduction. In this study, the unsafe behaviors of workers in Atieh Sazan construction Company, Tehran, Iran, were investigated. For this purpose, 452 workers were randomly selected and 11733 observations regarding unsafe behaviors were reported. In the second phase, Kiken Yochi Training was applied over three months, then observations were recorded once again. Socio-demographic questionnaire and Tarrant’s checklist were used. 25.69% of the recorded behaviors in the first phase and 18.57% after the intervention, were unsafe. Unsafe use of equipment and inappropriate ergonomic status were among the most common risky behaviors. The average percentages of unsafe behaviors before and after the intervention were reduced by about 36%. Kiken Yochi Training was effective in diminishing the unsafe behaviors among workers. There was a significant relationship between the number of unsafe behaviors, age, experience, type of occupation, educational status, and having a previous accident (P value

Introduction: The Surgical Safety Checklist has been introduced by the World Health Organization (WHO) as a tool for reducing medical errors. Reviewing the results of the checklist application indicates significant reduction in mortality and complications in surgery. Thus, this study aimed to customize and validate surgical safety checklist in order to complying with the surgical protocol in Iran. Material and Method: In this cross-sectional and descriptive study, the WHO Safety Surgery Checklist was first translated. Next, through interviews with specialists and direct observation of activities, those tasks that were susceptible to the incident, identified, prioritized and analyzed using Hierarchical Task Analysis (HTA) and the results presented in form of HTA charts. Then, using Tabulate Task Analysis (TTA) and based on the recommendation and modification commented by expert panel, some questions added to the checklist and a customized version of the Surgical Safety Checklist was provided. Hence, the faced validity, content validity and reliability of the checklist have been evaluated. Result: In the surgery, four major tasks identified for analyzing using the HTA chart. Accordingly, 41 subtasks obtained and analyzed by TTA. The Lavashe method was used to determine the content validity ratio (CVR) and the content validity index (CVI). The question from the checklist, in which, CVI was less than 0.79, modified and replaced with appropriate question. Also, the scores for 3 questions were less than 0.49, and they were removed from the checklist due to the low CVR score. In the reliability assessment, the intra-observer method is used, and the Kappa coefficient obtained was acceptable and it was higher than 0.6, which confirmed the validity of the checklist. Conclusion: In this study, the surgical safety checklist customized in terms of content validity and reliability, in a field study. Considering the compliance of the checklist items with the surgical protocol in Iran, we hope to use it to improve the quality of teamwork and reduce the complications and mortality caused by surgical errors

Background and aims: Clutch pedal is one of the most important control systems of automobile. As a foot controller due to the location and mechanisms of action, in case of improper design pedal clutch can reduce driver fatigue, as well as the comfort and safety of the vehicle. In the present research, clutch comfort of some common models of vehicles in taxi routes in Tehran were investigated from the viewpoint of ergonomics. Methods: In this cross-sectional and practical study, 120 drivers of taxi routes in Tehran were selected by stratified random sampling. Both objective (pressure-release force, frequency and duration of clutching) and subjective (specialized questionnaires) were used in order to assess fatigue and clutch comfort. Regarding objective assessments, the pressure-release force was measured using piezoelectric pressure dynamometer, and frequency and duration of clutching was estimated by means of a micro-switch named Data Logger. Results: Significant differences were observed in percieved discomfort in all bady parts involved in clutching, after the working shift. The highest discomfort belonged to back (3.97) and Knee (3.86) while the lowest value wer for upper thigh (1.45) and upper leg (1.98). Furthermore, drivers of Peykan and Roa automobiles reported the highest discomfort. Regarding the force and frequency of clutching, the hghest value was belonged to Peykan. Conclusion: According the the results, long-term use of the clutch pedal in all studied models of automobiles causes significant discomfort after the working shift. It is suggested that automobiles in Tehran taxi routes replace with the automatic gear ones and the Paykan and Roa, which showed the reatest discomfort) with other models.

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

Introduction: Teaching has been reported stressful. Although, the majority of teachers aren’t anxious or unmotivated and they even consider their job valuable and satisfying. Job demands-resources (JD-R) is a comprehensive model in occupational stress domain that simultaneously examines the stressful and motivational aspects of occupations and their related outcomes. Accordingly, the objective of this paper is to investigate job characteristics of teaching (job demands and job resources) and their subsequent outcomes by utilizing proposed model. Material and Method: This study was a cross-sectional design among 247 high school teachers in Tehran city who were selected by two-stage cluster sampling in spring and summer of 1391. Three aspects of job demands (pupil misbehavior, work-family conflict, and cognitive demand), 2 aspects of job resources (supervisory support and job condition), emotional exhaustion, vigor, teacher’s illness symptoms, and organizational commitment were assessed using job demands-resources model. The data were analyzed by means of SPSS 21 program and path analysis by using AMOS 23 program. Result: According to the results, model fit indices were in acceptable range and all the coefficient paths were significant (p

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.

Background and aims: Monitoring workerschr('39') work ability, planning to maintain and improve the work ability, and identifying and controlling its related risk factors are of the most important issues in the field of occupational health. The object of this study was to investigate the influence of factors related to work ability among farmers. Methods: The subjects consisted of 213 male farmers. This research examined the influence of demographic characterization, work-related factors and diseases on farmers’ work ability. Work ability was assessed using the Work Ability Index (WAI) and work-related factors were measure by Job Content Questionnaire (JCQ). Spearman correlation coefficient was used to employ to examine the relationship between WAI and its affecting factors. Results: Mean WAI score was 34.6 (SD±10.59) and it had a statistically significant relationship with age, BMI, diseases and work-related factors. The strongest correlation was found for diseases and physical work-related factors such as physical exertion (r=0.309), physical isometric loads (r=0.263), physical demands at work (r=0.322), while psychological factors showed a poorer correlation. Conclusion: According to findings, development of preventive approaches aimed at controlling diseases, eliminating awkward postures, reducing physical isometric loads, physical exertion and physical demands at work, as well as improving psychological work environment have an important role in promotion of the farmers’ work ability. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;}

Introduction: One of the important consequences of globalization and development, especially in developing countries, are occupational accidents. As, today the economic burden due to these accidents is remarkable on the country’s economy. The aim of this study was financial estimate of the productivity loss due to work-related deaths in Iran in 2013. Material and Method: In this study, occupational accident data were used registered in the environmental and occupational health center, in Iranian Ministry of Health and Medical Education. A formula used by the Centers for Disease Control and Prevention America (CDC) was used to estimate the productivity loss. Finally, after replacing the necessary parameters amount of productivity loss was calculated. Result: The total lost years of life were calculated 1293.15 years due to the deaths caused by occupational accidents. The total amount of monetary loss due to the productivity loss in the country, was estimated 730513.06 Rials. The greatest loss was in the 59-50 years old age group. Conclusion: The negative rate of productivity, the large quantity of the discount rate, low life expectancy in the country as well as the low wages of the workers, are the likely reasons for minimal negative impact of the workforce deaths on the country’s productivity.

Workers in industrial workplaces are at increased risk of developing, occupational hazards, work-related accidents, and diseases. Personal Protective Equipment use (PPE) may protect the user against accident or safety risks in the working environment. Educational interventions may improve knowledge and practice related to prevention, but little is known about their knowledge and exposure prevention. This study was aimed to determine the effect of educational intervention based on social cognitive theory (SCT) on knowledge and (PPEs) use among Iranian workers of Aluminum Company (IRALCO). This parallel randomized trial was conducted in a sample of 188 workers who were randomly assigned as the intervention (n=94) and a control (n=94) groups. The intervention group received an educational intervention of six sessions lasting 45-60 minutes augmented with the electronic-learning whereas; the control group attended a routine education program of the company. A researcher-made questionnaire based on SCT constructs and a practice/checklist was used to collect data at baseline and six months after the intervention. Mann-Whitney Test and Wilcoxon Signed Ranks Test analysis were used for data analysis using SPSS version 24.0. P0.05). This study indicated that the application of educational intervention based on SCT constructs can reflect a positive impact on knowledge and appropriate use of PPEs to reduce occupational-related injuries. This theory is a recommended method to improve workers’ personal protective behaviors.

Background: Low back pain caused by work, ranked the second after cardiovascular diseases, are among the most common reasons of patients’ referral to the physicians in Iran. This study aimed to determine the changes in back compressive force when measuring maximum acceptable weight of lift in Iranian male students.Methods: This experimental study was conducted in 2015 on 15 young male students were recruited from Tehran University of Medical Science. Each participant performed 18 different lifting tasks involving three lifting frequencies, with three lifting heights, and two box sizes. Each set of experiments was conducted during the 20 min work period using free-style lifting technique. The back compressive force evaluated with hand-calculation back compressive force method. Finally, Pearson correlation test, analysis of variance (ANOVA) and t-test were used for data analysis.Results: The mean of back compressive force (BCF) for the small and large boxes at a frequency of 1lift/min at heights of F - K height, were 1001.02 (±86.74), 1210.57 (±93.77) Ib, respectively. There was a significant difference between mean BCF in terms of frequencies of lifts (P=0.02). The result revealed significant difference between frequencies of 1 lift/min and 6.67 lift/min (P=0.01). There was a significant difference between mean BCF in terms of the sizes of the two boxes (P=0.001). There was a significant relationship between the BCF and maximum acceptable weight of lift in all test conditions (P=0.001).Conclusion: BCF is affected by box size, lifting frequency and weight of load. Keywords: Back compressive force, Maximum acceptable weight of lift, Psychophysical methodology

Introduction: High level of workload and its consequent cognitive failures are among factors which impact nurses’ behavior, performance, and efficiency. This study aimed to investigate the relationship between nurses’ cognitive failures and perceived workload. Material and Method: This cross-sectional and descriptive-analytical study was carried out among 150 male and female nurses, working in different units of Emam Khomeini and Vali-e-Asr hospitals in Tehran in 2013. NASA task load index (NASA-TlX) and Cognitive Failure Questionnaire (CFQ) were used to assess workload and cognitive failures, respectively. Data were analyzed using Pearson Correlation, Independent sample t-test, and one-way ANOVA statistical tests with SPSS software version 20. Result: Pearson and Spearman correlation coefficients test results showed a significant relationship between nurses’ mental workload and their memory for names (P-value

Background: High level of workload has been identified among stressors of nurses in intensive care units (ICUs). The present study investigated nursing workload and identified its influencing perfor­mance obstacles in ICUs. Methods: This cross-sectional study was conducted, in 2013, on 81 nurses working in ICUs in Imam Khomeini Hospital in Tehran, Iran. NASA-TLX was applied for assessment of workload. Moreover, ICUs Performance Obstacles Questionnaire was used to identify performance obstacles associated with ICU nursing. Results: Physical demand (mean=84.17) was perceived as the most important dimensions of workload by nurses. The most critical performance obstacles affecting workload included: difficulty in finding a place to sit down, hectic workplace, disorganized workplace, poor-conditioned equipment, waiting for using a piece of equipment, spending much time seeking for supplies in the central stock, poor quality of medical materials, delay in getting medications, unpredicted problems, disorganized central stock, outpatient surgery, spending much time dealing with family needs, late, inadequate, and useless help from nurse assistants, and ineffective morning rounds (P-value

Nurses have always been considered as a unique working group because of the physically and mentally demanding tasks they bear at work. Such a working condition exposes them to a high risk of fatigue, which could influence their work ability. Therefore, this study aims to investigate the relationship between work ability index (WAI) and fatigue of critical care nurses in a military hospital. In this descriptive and cross-sectional study, 101 nurses (71 females and 30 males) of critical care units filled out both the Persian version of WAI and nurses’ fatigue questionnaires. The nurses were selected from three general hospitals of Tehran by cluster sampling method. The Pearson correlation test was used for investigating the relationship between two quantitative variables, and all the statistical analyses were performed by SPSS v. 21 software. The nurses’ average age was 24.5 years old (±SD=±3.6), and the mean of work experience was 9 years (±SD=±4.13). The mean work ability of the nurses was 40.01 (±SD=±4.05), indicating “good work ability”. Fatigue was found in 46.19% of the participants, and the nurses’ fatigue was mainly of mental type (29.8%). There was a significant negative correlation (-0.57) between the scores of WAI and total fatigue (p < 0.001). The negative correlation between WAI and fatigue shows that WAI and fatigue score could be a good predictor of health and quality of work life. Identifying the influential factors of nurses’ work ability and fatigue would help to improve the work condition of critical care nurses.

Work-related accidents and illnesses are a great concern in developed countries. Numerous researches have been performed to find an appropriate approach to decrease occupational accidents. This descriptive-analytical study was designed based on the retrospective and field studies to develop a customized model of the safety culture and identify the effective factors of safety culture in a car manufacturing company. In order to present a new customized model of safety culture questionnaire, the study was designed in three phases: 1) Proposing a customized model, 2) Constructing a validated questionnaire, and 3) Conducting a field study. A total number of 619 cases completed the questionnaire (321 injured and 298 uninjured people). Cronbach's alpha of the questionnaire was 0.855. The injured population noticeably acquired more points than the uninjured workers in all items of the questionnaire except for "safety rules and regulations"; though, this difference was statistically significant (P

Background: Drowsiness is one of the underlying causes of driving accidents, which contribute, to many road fatalities annually. Although numerous methods have been developed to detect the level of drowsiness, techniques based on image processing are quicker and more accurate in comparison with the other methods. The aim of this study was to use image-processing techniques to detect the levels of drowsiness in a driving simulator. Methods: This study was conducted on five suburban drivers using a driving simulator based on virtual reality laboratory of Khaje-Nasir Toosi University of Technology in 2015 Tehran, Iran. The facial expressions, as well as location of the eyes, were detected by Violla-Jones algorithm. Criteria for detecting drivers’ levels of drowsiness by eyes tracking included eye blink duration blink frequency and PERCLOS that was used to confirm the results. Results: Eye closure duration and blink frequency have a direct ratio of drivers’ levels of drowsiness. The mean of squares of errors for data trained by the network and data into the network for testing, were 0.0623 and 0.0700, respectively. Meanwhile, the percentage of accuracy of detecting system was 93. Conclusion: The results showed several dynamic changes of the eyes during the periods of drowsiness. The present study proposes a fast and accurate method for detecting the levels of drivers’ drowsiness by considering the dynamic changes of the eyes.

Background: Recently, considerable attention has been paid to medical errors in health care system. Taking into account that nurses spend more time with patients in comparison with other staff, they are more prone to human errors. The present research conducted to investigate nurseschr('39') errors in delivery emergency ward in a hospital affiliated to Tehran University of Medical Sciences. Material and Methods: In the present coss-sectional study,at first, task analysis was conducted to nursing proffession using Hierarchical Task Analysis (HTA) technique by FGD. In next step, the Human Error Probability (HEP) was determined utilizing SPAR-H method and dependences of performance-shaping factors (PSFs) and action and diagnosis activities were identified. Finally, after determinig dependency level, the final diagnosis HEP was calculated and risk assessment level was carried out using the riskschr('39') probability and intensity tables. Results: According to the results, four groups of studied tasks, the lowest errors were belonged to "working with serum pumping machinechr('39')chr('39') subtask with the error level of 0.055 and the highest error probability related to chr('39')chr('39') transfusion of blood productschr('39')chr('39') subtask with the error rate of 0.78. Moreover, special responsibilities of the wards had the highest level of undesirable risks. Conclusion: In the present study, the analysis of identified errors reveals due to high work demand, insufficient time and the need for accurate administrative monitoring and providing required arrangements, the main causes of errors can be attributed to high level of stress and complexity in the tasks of delivery emergency ward.

Background:Heat stress, as one of the most common occupational health problems, can impair operators' cognitive processes. The aim of this study was to evaluate the impact of thermal stress on cognitive function among workers in a hot industry. Methods: In this cross-sectional study conducted in Malibel Saipa Company in 2013, workers were assigned into two groups: one group were exposed to heat stress (n=35), working in casting unit and the other group working in machin-ing unit (n=35) with a normal air conditioning. Wet Bulb Globe Temperature was measured at three heights of ankle, abdomen, and head. In order to evalu-ate the effects of heat stress on attention and reaction time, Stroop tests 1, 2, and 3 were conducted before starting the work and during the work. Results: A significant positive correlation was observed between WBGT and test duration (P=0.01) and reaction time of Stroop test 3 (P=0.047), and be-tween number of errors in Stroop tests 1, 2, and 3, during the work (P= 0.001). Moreover, Stroop test 3 showed a significant higher score for both test dura-tion and reaction time of workers in case group. Conclusion: Results of the present study, conducted in a real work environment, confirmed the impairment of cognitive functions, including selective attention and reaction time, under heat stress conditions.

Control room is the heart of each system in which even a minor error can result in irrecoverable consequences. The purpose of this study was to determine the Probable Control Modes (PCMs) and Cognitive Failure Probability (CFP), and also build a Cognitive Demands Profile (CDP) in a petrochemical control room, using Cognitive Reliability and Error Analysis technique (CREAM). First, tasks of Boardman (B.M), Shift Control (S.C), and Head Control (H.C) in control room were analyzed, applying hierarchical task analysis. Following, PCM, CFP and CDP were determined for the analyzed tasks. According the results, control modes for the tasks of B.M and S.C were determined as opportunistic; while for H.C tasks it was obtained as tactical. Of the all error types, execution failure (48.57%), interpretation failure (18.57%), planning failure (15.71%), and observation failure (17.15%) were identified. The most important CDPs were communicated, monitor, execute, plan, diagnose, evaluate, co-ordinate, verity, record, and scan. Based on the findings, number of simultaneous goals, time of day and adequacy of training and experience in the study field were the Common Performance Conditions that led to reduction of performance reliability. These factors contributed to the opportunistic control mode. In order to prevent or reduce cognitive errors in the control room, we need to know the exact type of cognitive activities, and develop a comprehensive program to increase the knowledge and skills for performing the cognitive activities.

Background: We determined the levels of subjective and observer drowsiness and facial dynamics changes. Methods: This experimental study was done in the virtual reality laboratory of Khaje-Nasir Toosi University of Technology in 2015. Facial dynamics changes like changes in eyes, mouth and eyebrows were surveyed on twenty-five drivers in 2015byKSS (Karolinska Sleepiness Scale) and ORD (Observer Rating of Drowsiness). ANOVA Repeated Measure and MANOVA Repeated Measure tests were used for data analysis. Also, neural network and Viola-Jones were used to detect facial characteristics. PERCLOS (Percentage of Eye Closure), blink frequency and blink duration were inspected for eyes parameters. The size of open mouth during drowsiness was inspected for mouth parameter. During the inspection of eyebrow, the number 50 denoted eyebrow in normal position. For eyebrows above the normal position, a range of 50 to 55 was specified; in addition, 45-50 was found as the specified range for eyebrows under normal position. Results: Descriptive statistics of the dynamic changes in mouth and eyes illustrated that during the driving process, the level of sleepiness increased as well as changes of eyes and mouth. However, statistical findings during car driving revealed that dynamic changes in eyebrows had clear expression with a constant trend. Similar studies on data obtained from KSS and ORD showed that both of these parameters simultaneously increased as well as the level of drowsiness. In addition, a significant relationship existed between facial expression and drowsiness. Conclusion: This research would be an effective and efficient tool for timely alarming and detecting the drowsiness quickly and precisely.

Background & Objectives : Approximately one third of all reported work-related incidents are triggered by manual handling. The proportion of incidents associated with manual handling in health and social care is 38%. Lifting and transferring patients is the task that is most often cited as a cause of manual handling incidents and of back injury in the healthcare sector. The aim of this study is to determine the MAPO index for remedial hospital wards of Qazvin and considering its relationship with incidence and intensity of musculoskeletal disorders among servers whose main task is manual handling of patients . Methods : In this cross sectional study, 54 cases of servers from 23 wards of 4 Hospitals was considered. The data was collected using the demographic characteristic questionnaire, the Verbal pain intensity scale, the Nordic questionnaire and the MAPO checklist. Statistical Analysis of collected data was performed with SPSS 22. Results : One year prevalence of musculoskeletal disorders was 75.9% and this amount during performing this study was reported 53.7%. Regarding to different levels of MAPO score, just 5.5% of surveyed personnel were in safe zone. 18.5% of them exposed to moderate risk of musculoskeletal disorders and 76 % were at high risk. Also prevalence of musculoskeletal disorders incidents and pain intensity had significantly associated with the MAPO index score. Conclusion : Regarding to association between MAPO index score and prevalence of musculoskeletal disorders, to reducing incidences risk, improvement of MAPO index parameters to reducing its amount will be effective.

Background & Objectives: According to previous researches, workers' participation in issues affecting their working condition is the key to success in ergonomics interventions in working environments. Therefore, the present study was performed to increase active particapitation of supervisors in production line and also to identify and assess ergonomics risks and presenting modification actions (Kaizen) by themselves in Pars Khodro automobile manufacturing company. Methods: A manual regarding lifting objects and body postures, according to the Finish evaluation method, was provided for supervisors in production line and related trainings were presented to them. Then, they were asked to insert the results of their assessments and suggestions in special forms during one year. The presented assessments and suggestions were examined by ergonomics experts. Results: According to the assessments conducted by supervisors, 26 work stations had high ergonomics risks, 51 had ergonomics risks with an average level, and 45 had low ergonomics risks. Moreover, the number of required Kaizens presented by supervisors was increased from 18 cases in the first year to 42 cases in the second year, after implementation of ergonomics training and identifying and assessing ergonomic risks by supervisors. Conclusion: Empowering and training supervisors increased workers' participation. In case of adequate training, supervisors can present practical solutions to reduce ergonomics risks in their workstations.

Background & Objectives : In case of inappropriateness of the dimensions of chairs or when users feel pain and pressure in their lumbar region due to poor posture, damage to the spine can be prevented using some additional supports. The aim of this study was ergonomic evaluation of one of these supportive products named “Spine Fit”. Methods : In this descriptive and cross-sectional study, in the first stage, five ergonomists evaluated the product regarding its dimension, adjustability, material, conformity, and manufacturer claims. Then, three groups of workers including office workers, office workers with low back pain, and bus drivers filled out a self-administered questionnaire after using Spine Fit . Results : For the first stage, an acceptable adjustability and dimension was found. Conformity for different kinds of office and bus seats was mostly fair. Findings from the second stage revealed that the subjects in three groups were satisfied regarding seats comfort and ease of use. Concerning the conformity of Spine Fit, it was in good level among office workers, while different levels of conformity were observed by drivers of different models of bus . Conclusion : Spine Fit supports back region based on its supportive role in pelvis, lumbar vertebrae column and thoracic spine. Moreover, Spine Fit features that reduce sweating can improve individuals’ convenience.

Introduction: Human errors are of the most important issues due to the technological advances in various work settings. In medical professions, including nursing, investigation of human errors would help to find out approaches for the identification and reduction of these errors. Hence, the present study aimed to identify and assess nurses' errors in emergency ward of an educational hospital, using Systematic Human Error Reduction and Prediction Approach (SHERPA). Method: In this qualitative study, first, the purpose and the procedure of the research were completely explained to the nurses. Then, Hierarchical task analysis (HTA) was done and the nurses' tasks and subtasks were identified by observing their activities and conducting interviews. Then, the SHERPA worksheet was completed to find the errors pertinent to each task. Discussion: Sixty-five tasks and 231 errors were detected regarding the nurse's tasks, of which 59.3% was action errors, 25.55% checking errors, 4.33% retrieval errors, 2.16% information communication errors, and 8.66% selection errors. This means that the highest and lowest errors were respectively belonged to action errors and communication errors. Moreover, the checking errors obtained the highest undesirable risk level. Result: Overall, the action errors and the checking errors should be priority in controlling and reducing of nurses errors in emergency ward. It should be noted that SHERPA can cover a wide range of activities including factors such as patients and their caregivers or other wards of the hospitals which make this technique an appropriate tool for assessing the errors in medical professions.

Background: Driver fatigue is one of the major implications in transportation safety and accounted for up to 40% of road accidents. This study aimed to analyze the EEG alpha power changes in partially sleep-deprived drivers while performing a simulated driving task. Methods: Twelve healthy male car drivers participated in an overnight study. Continuous EEG and EOG records were taken during driving on a virtual reality simulator on a monotonous road. Simultaneously, video recordings from the driver face and behavior were performed in lateral and front views and rated by two trained observers. Moreover, the subjective self-assessment of fatigue was implemented in every 10-min interval during the driving using Fatigue Visual Analog Scale (F-VAS). Power spectrum density and fast Fourier transform (FFT) were used to determine the absolute and relative alpha powers in the initial and final 10 minutes of driving. Results: The findings showed a significant increase in the absolute alpha power (P = 0.006) as well as F-VAS scores during the final section of driving (P = 0.001). Meanwhile, video ratings were consistent with subjective self-assessment of fatigue. Conclusion: The increase in alpha power in the final section of driving indicates the decrease in the level of alertness and attention and the onset of fatigue, which was consistent with F-VAS and video ratings. The study suggested that variations in alpha power could be a good indicator for driver mental fatigue, but for using as a countermeasure device needed further investigations. Keywords: Driver mental fatigue, F-VAS, Video rating, EEG alpha power.