A method for rapid assessment of visual ergonomics and lighting conditions (RAVEL): An in-depth development and psychometrics study.

BACKGROUND: In workplaces heavily reliant on visual tasks, various factors can significantly influence an individual's performance, necessitating the use of reliable tools to identify and mitigate these factors. OBJECTIVE: This study aimed to develop a swift assessment method for visual ergonomics and lighting conditions, evaluating its validity in real-world scenarios. METHODS: The questionnaire's content validity was determined by a panel of experts using the content validity ratio (CVR) and content validity index (CVI). Construct validity was assessed through exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and latent class analysis (LCA). Internal consistency was measured using Cronbach's alpha coefficient. The RAVEL index, derived from the calculated effect coefficients of items, classified total scores through receiver operator curves (ROCs). RESULTS: The rapid assessment method, comprising two parts with 30 items, demonstrated acceptable reliability with CVR, CVI, and Cronbach's alpha coefficient (α) at 0.75, 0.87, and 0.896, respectively. The EFA on the first part's 22 items identified three factors, confirmed by CFA. The LCA on the second part's eight items revealed that a two-class model best fit the data, with Bayesian information criterion (BIC) = 24249, 17, Akaik information criterion (AIC) = 2179.89, and an entropy R-squared of 0.83, indicating appropriate subject classification based on the model. The RAVEL score was categorized into three levels, with optimal cut points of 55 and 63. CONCLUSIONS: In conclusion, the study demonstrated that this method based on visual ergonomics serves as a rapid and reliable tool for assessing visual ergonomic risks of display users in the workplace.

A novel framework for human factors analysis and classification system for medical errors (HFACS-MES)-A Delphi study and causality analysis.

The healthcare system (HCS) is one of the most crucial and essential systems for humanity. Currently, supplying the patients' safety and preventing the medical adverse events (MAEs) in HCS is a global issue. Human and organizational factors (HOFs) are the primary causes of MAEs. However, there are limited analytical methods to investigate the role of these factors in medical errors (MEs). The aim of present study was to introduce a new and applicable framework for the causation of MAEs based on the original HFACS. In this descriptive-analytical study, HOFs related to MEs were initially extracted through a comprehensive literature review. Subsequently, a Delphi study was employed to develop a new human factors analysis and classification system for medical errors (HFACS-MEs) framework. To validate this framework in the causation and analysis of MEs, 180 MAEs were analyzed by using HFACS-MEs. The results showed that the new HFACS-MEs model comprised 5 causal levels and 25 causal categories. The most significant changes in HFACS-MEs compared to the original HFACS included adding a fifth causal level, named "extra-organizational issues", adding the causal categories "management of change" (MOC) and "patient safety culture" (PSC) to fourth causal level", adding "patient-related factors (PRF)" and "task elements" to second causal level and finally, appending "situational violations" to first causal level. Causality analyses among categories in the HFACS-MEs framework showed that the new added causal level (extra-organizational issues) have statistically significant relationships with causal factors of lower levels (Φc≤0.41, p-value≤0.038). Other new causal category including MOC, PSC, PRF and situational violations significantly influenced by the causal categories of higher levels and had an statistically significant effect on the lower-level causal categories (Φc>0.2, p-value<0.05). The framework developed in this study serves as a valuable tool in identifying the causes and causal pathways of MAEs, facilitating a comprehensive analysis of the human factors that significantly impact patient safety within HCS.

Mental workload profile and its relationship with presenteeism, absenteeism and job performance among surgeons: The mediating role of occupational fatigue.

Introduction: Surgeons are one of the most significant jobs in the health care system that plays an important role in the patients' health promotion and their treatment. In the current study, the effect of mental workload on the work performance of surgeons was tested by considering the mediating effect of fatigue on this relationship. Method: This study was done analytically on 165 surgeons working in the operating rooms of hospitals in Iran. To determine of mental workload, the SURG-TLX method was used. The job performance was measured using the short version of the job performance questionnaire provided by the World Health Organization (WHO-HPQ), and accordingly relative presenteeism, relative absenteeism and job performance variables were calculated. The Swedish Occupational Fatigue Inventory (SOFI) questionnaire was used to determine occupational fatigue. A conceptual model was built to determine the direct and indirect relationship between mental workload and job performance, and the mediating effect of occupational fatigue on the relationship between mental workload and job performance was tested using structural equation modeling (SEM). Results: Out of 165 distributed questionnaires, 140 questionnaires were completed and delivered to the researchers (85% response rate). The mean ± standard deviations of mental workload, fatigue, and work performance were 16.57 ± 5.83, 6.32 ± 2.86, and 0.65 ± 0.28, respectively. The results of model fit indexes revealed that all indexes are within the acceptable range. Regarding this model, the direct effect of mental workload on job performance was not significant (ß = -0.21; p = 0.072). A significant positive relationship was observed between mental workload and fatigue (ß = 0.36; p < 0.001). The direct effect of fatigue on job performance was also the opposite and statistically significant (ß = -0.39; p < 0.001). Finally, results indicated that the effect of mental workload on work performance mediated by occupational fatigue. Conclusion: Surgeons suffer a high level of mental workload during their work, and this factor can have a negative effect on surgeons' job performance. The effect of mental workload on job performance in surgeons can be detected, directly and indirectly, through the mediating effect of occupational fatigue. Improving the mental and physical conditions of the work environment can reduce occupational fatigue and improve surgeons' job performance.

Application of "Human Factor Analysis and Classification System" (HFACS) Model to the Prevention of Medical Errors and Adverse Events: A Systematic Review.

Hospitals, as one of most important subsectors in human societies, are responsible for providing safe and effective medical services to clients. But sometimes these hospitals are the source of injury and death in patients by creating medical errors. In this systematic review study, the application of human factor analysis and classification system (HFACS) method in the classification of medical errors was investigated. Major electronic databases including Scopus, Web of Science, and MEDLINE were searched. All studies that investigated the application of HFACS method for coding, causation, and classification of medical errors and adverse events conducted from 2001 until February 2021 were included. A total of 108 articles were found. Due to duplication, 18 studies were removed from the review list. After reading the titles and abstracts, 50 of these publications were excluded because they had objectives different from this review. The remaining 40 publications were retrieved for further assessment. Of these, 28 publications were excluded because it did not meet the inclusion criteria. Finally, 12 articles remained for the final systematic review. We found that in 65% of the selected studies, preconditions for unsafe acts have been the major causal level of medical errors and adverse events. In the majority of the studies, communication and coordination, adverse mental states, physical environment, crew resource management, and technological environment have also been recognized as the most important causal categories in this study. As a result, to prevent medical errors and adverse events, the main focus should be on controlling the preconditions for unsafe acts including personnel factors, operator conditions, and environmental factors.

The Effect of Sleep Quality and Mental Fatigue on the Learning Rate of Shift Workers with Fast Shift Work Rotation.

Background: Modern industrial societies are always prone to errors and accidents due to complex devices, multitasking, and shift work jobs. Therefore, behavioral tests in learning and memory are necessary to evaluate employees' perceptions to examine the brain's information processing and the physiological and psychological aspects of memory disorders. Materials and Methods: In this study, the effect of fast shift rotation, sleep quality, and mental fatigue on individuals' learning and memory was investigated using a maze device. Participants were divided into two groups (regular daytime workers and shift workers). The quality of sleep was assessed using the Pittsburgh Sleep Quality Index (PSQI), and the rate of mental fatigue was evaluated using a checklist published by the Japan Industrial Safety and Health Association. Results: Learning time and the number of learning errors at the beginning and end of the morning shifts and night shifts had a significant relationship (P value <0.0001). However, there was no meaningful relationship between sleep quality and time and the number of learning errors in day workers and shift workers. Conclusion: The results indicated that although shift workers experience rapid shift rotation, they are still exposed to this circadian sleep change's side effects such as general physical fatigue, sensory-neurological fatigue, poor perceived sleep quality, daily dysfunction, difficulty in learning, and memory. They show a significant difference compared to people working on a regular workday.

Optimization of the ANFIS using a genetic algorithm for physical work rate classification.

Purpose. Recently, a new method was proposed for physical work rate classification based on an adaptive neuro-fuzzy inference system (ANFIS). This study aims to present a genetic algorithm (GA)-optimized ANFIS model for a highly accurate classification of physical work rate. Methods. Thirty healthy men participated in this study. Directly measured heart rate and oxygen consumption of the participants in the laboratory were used for training the ANFIS classifier model in MATLAB version 8.0.0 using a hybrid algorithm. A similar process was done using the GA as an optimization technique. Results. The accuracy, sensitivity and specificity of the ANFIS classifier model were increased successfully. The mean accuracy of the model was increased from 92.95 to 97.92%. Also, the calculated root mean square error of the model was reduced from 5.4186 to 3.1882. The maximum estimation error of the optimized ANFIS during the network testing process was ± 5%. Conclusion. The GA can be effectively used for ANFIS optimization and leads to an accurate classification of physical work rate. In addition to high accuracy, simple implementation and inter-individual variability consideration are two other advantages of the presented model.

Comparing the Effectiveness of Three Ergonomic Risk Assessment Methods-RULA, LUBA, and NERPA-to Predict the Upper Extremity Musculoskeletal Disorders.

BACKGROUND: Musculoskeletal disorders are a major problem in all jobs. Several methods are available for assessing the exposure to risk factors associated with musculoskeletal disorders. This study is aimed at comparing three different ergonomic risk assessment methods-rapid upper limb assessment (RULA), loading on the upper body assessment (LUBA), and new ergonomic posture assessment (NERPA) method-to predict upper extremity musculoskeletal disorders. MATERIALS AND METHODS: The study was conducted on 210 workers from three different industries including pharmaceutical, automotive, and assembly in the Isfahan province. A Nordic questionnaire was used for determining the levels of musculoskeletal disorders. Then, selected postures were evaluated with RULA, LUBA, and NERPA methods. Finally, data were analyzed with Kolmogorov-Smirnov test to check the normality distribution of data, Spearman's correlation test to investigate the correlation between the assessed levels with musculoskeletal disorders, and Wilcoxon test to identify significant differences between the values with SPSS version 16. RESULTS: Wilcoxon test revealed a significant difference between the values related to NERPA and RULA (P < 0.001), whereas no significant relation between LUBA and RULA was shown by this test (P = 0.914). The correlation coefficients of the musculoskeletal disorders' level with RULA level, NERPA level, and LUBA level were 0.74, 0.73, and 0.69, respectively. CONCLUSION: Low-risk levels in NERPA, medium-risk levels in LUBA, and high-risk levels in RULA are evaluated better. The results showed that RULA was the best method for assessing musculoskeletal disorders among the three methods.

The effect of three ergonomics interventions on body posture and musculoskeletal disorders among stuff of Isfahan Province Gas Company.

BACKGROUND: Prevalence of work-related musculoskeletal disorders (WMSDs) is high among computer users. The study investigates the effect of three ergonomic interventions on the incidence of musculoskeletal disorders among the staff of Isfahan Province Gas Company, including training, sport, and installation of software. MATERIALS AND METHODS: The study was performed in the summer of 2013 on 75 (52 men, 23 women) Isfahan Province Gas Company employees in three phases (phase 1: Evaluation of present situation, phase 2: Performing interventions, and phase 3: Re-evaluation). Participants were divided into three groups (training, exercise, and software). The Nordic Musculoskeletal Questionnaire (NMQ) and rapid upper limb assessment (RULA) were used. Data collected were analyzed using SPSS software and McNemar test, t-test, and Chi-square test. RESULTS: Based on the evaluations, there was a decrease in musculoskeletal symptoms among the trained group participants after they received the training. McNemar test showed that the lower rate of pain in low back, neck, knee, and wrist was significant (P < 0.05). The results obtained from the RULA method for evaluation of posture showed an average 25 points decrease in the right side of the body and 20 points decrease in the left side of the body in the group subjected to training. Based on t-test, the decrease was significant. CONCLUSION: The study demonstrated that majority of the participants accepted interventions, which indicates that most of the people were unsatisfied with the work settings and seeking improvement at the workplace. Overall, the findings show that training, chair adjustment, and arrangement in workplace could decrease musculoskeletal disorders.

Job strain (demands and control model) as a predictor of cardiovascular risk factors among petrochemical personnel.

BACKGROUND: One of the practical models for the assessment of stressful working conditions due to job strain is job demand and control model, which explains how physical and psychological adverse consequences, including cardiovascular risk factors can be established due to high work demands (the amount of workload, in addition to time limitations to complete that work) and low control of the worker on his/her work (lack of decision making) in the workplace. The aim of this study was to investigate how certain cardiovascular risk factors (including body mass index [BMI], heart rate, blood pressure, cholesterol and smoking) and the job demand and job control are related to each other. MATERIALS AND METHODS: This prospective cohort study was conducted on 500 workers of the petrochemical industry in south of Iran, 2009. The study population was selected using simple random statistical method. They completed job demand and control questionnaire. The cardiovascular risk factors data was extracted from the workers hygiene profiles. Chi-square (χ (2)) test and hypothesis test (η) were used to assess the possible relationship between different quantified variables, individual demographic and cardiovascular risk factors. RESULTS: The results of this study revealed that a significant relationship can be found between job demand control model and cardiovascular risk factors. Chi-square test result for the heart rate showed the highest (χ (2) = 145.078) relationship, the corresponding results for smoking and BMI were χ (2) = 85.652 and χ (2) = 30.941, respectively. Subsequently, hypothesis testing results for cholesterol and hypertension was 0.469 and 0.684, respectively. DISCUSSION: Job strain is likely to be associated with an increased risk of cardiovascular risk factors among male staff in a petrochemical company in Iran. The parameters illustrated in the Job demands and control model can act as acceptable predictors for the probability of job stress occurrence followed by showing a high trend of CVD risk factors.

Relationship between mental workload and musculoskeletal disorders among Alzahra Hospital nurses.

BACKGROUND: Musculoskeletal disorders (MSDs) are a serious problem among the nursing staff. Mental workload is the major cause of MSDs among nursing staff. The aim of this study was to investigate the mental workload dimensions and their association with MSDs among nurses of Alzahra Hospital, affiliated to Isfahan University of Medical Sciences. MATERIALS AND METHODS: This descriptive cross-sectional study was conducted on 247 randomly selected nurses who worked in the Alzahra Hospital in Isfahan, Iran in the summer of 2013. The Persian version of National Aeronautics and Space Administration Task Load Index (NASA-TLX) (measuring mental load) specialized questionnaire and Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) was used for data collection. Data were collected and analyzed by Pearson correlation coefficient and Spearman correlation coefficient tests in SPSS 20. RESULTS: Pearson and Spearman correlation tests showed a significant association between the nurses' MSDs and the dimensions of workload frustration, total workload, temporal demand, effort, and physical demand (r = 0.304, 0.277, 0.277, 0.216, and 0.211, respectively). However, there was no significant association between the nurses' MSDs and the dimensions of workload performance and mental demand (P > 0.05). CONCLUSIONS: The nurses' frustration had a direct correlation with MSDs. This shows that stress is an inseparable component in hospital workplace. Thus, reduction of stress in nursing workplace should be one of the main priorities of hospital managers.

A survey of the relationship between work schedule and its effect on the fatigue of rescue personnel in Isfahan with a standard method of CIS202.

CONTEXT: Fatigue is a factor that can have negative effects on family life, social relationship and work. Work schedule is one of the affective factors on personnel's fatigue in different jobs. In this study, the work schedule and its effect on rescue personnel in Isfahan are explored. AIMS: The purpose of this study was to investigate the relationship between work schedules and fatigue among rescue personnel. SETTINGS AND DESIGN: This study is periodical and has been conducted on 72 employees of rescue personnel in Isfahan. MATERIALS AND METHODS: Random sampling was done and the primary data that was collected through fatigue assessment questionnaire after being conducted as a pilot study on 10% of samples were collected to confirm the validity of this study. Finally, the data was given to SPSS11.5 software and were analyzed by descriptive statistics and linear digression. RESULTS: The results showed that from the statistical point of view some parts of work schedules like work hours satisfaction, resting time and work order on total fatigue are effective in linear and inverse way but the item "predictibility of work conditions" does not have a meaningful relationship with total fatigue. Furthermore, the results showed that there is a meaningful and inverse relationship with work hours, resting time and work order with mental fatigue and also the work schedule has a meaningful, linear and inverse relation with mental fatigue and total fatigue. CONCLUSIONS: By increasing the satisfaction of working hours, increasing resting time and also with an increase of work order the total fatigue of rescue personnel will decrease.

Study of the relationship between the aerobic capacity (VO2 max) and the rating of perceived exertion based on the measurement of heart beat in the metal industries Esfahan.

BACKGROUND AND OBJECTIVE: To establish a balance between work (physical exercise) and human beings, the aerobic capacity (VO2 max) could be used as a measure. Additionally, the subjective and physiological assessment could be applied as one of the methods for assessing physical exercise. The most commonly used tools for the assessment of fatigue during physical exercise include the Borg scale Rating of perceived Exertion (RPE) in relation to subjective symptoms and heart rate (HR) in relation to physiological symptoms. The study is aimed to investigate the relationship between the aerobic capacity and the RPE based on the measurement of heat rate (HR) of workers from the Metal Industries of Isfahan. MATERIALS AND METHODS: The subjects were 200 male workers from metal components manufacturers in Isfahan selected by using random sampling based on statistic method. The subjects were examined by using ergometer in accordance with A strand 6 minutes cycle test protocol. Furthermore, the subjects were asked to rate their status based on the Borg rating scale at the end of each minute. Additionally, their heat rates were monitored and recorded automatically at the end of each minutes. RESULTS: Statistical analysis showed that there was a significant relationship between the RPE and the aerobic capacity (VO2 max) (r = -0.904, P < 0.05). The results illustrated that there was a stronger correlation between HR and VO2 max (r = 0.991, P < 0.001). The regression analysis of the quadratic equation also indicated that there was also a significant relationship between the VO2 max and HR. CONCLUSIONS: The results indicated that there was a strong relationship between the RPE and VO2 max, as well as a greater correlation between HR and VO2 max. Therefore, the HR could be used as a Prediction measure to estimate VO2 max.

Designing and validation a visual fatigue questionnaire for video display terminals operators.

BACKGROUND: Along with the rapid growth of technology its related tools such as computer, monitors and video display terminals (VDTs) grow as well. Based on the studies, the most common complaint reported is of the VDT users. METHODS: This study attempts to design a proper tool to assess the visual fatigue of the VDT users. First draft of the questionnaire was prepared after a thorough study on the books, papers and similar questionnaires. The validity and reliability of the questionnaire was confirmed using the content validity index (CVI) beside that of the Cronbach's Coefficient Alpha. Then, a cross-sectional study was carried out on 248 of the VDT users in different professions. A theoretical model with four categories of symptoms of visual fatigue was derived from the previous studies and questionnaires. Having used the AMOS16 software, the construct validity of the questionnaire was evaluated using the confirmatory factor analysis. The correlation co-efficiency of the internal domains was calculated using the SPSS 11.5 software. To assess the quality check index and determining the visual fatigue levels, visual fatigue of the VDT users was measured by the questionnaire and visual fatigue meter (VFM) device. Cut-off points were identified by receiver operating characteristic curves. RESULTS: CVI and reliability co-efficiency were both equal to 0.75. Model fit indices including root mean of squared error approximation, goodness of fit index and adjusted goodness of fit index were obtained 0.026, 0.96 and 0.92 respectfully. The correlation between the results measured with the questionnaire and VFM-90.1 device was -0.87. Cut-off points of the questionnaire were 0.65, 2.36 and 3.88. The confirmed questionnaire consists of four main areas: Eye strain (4 questions), visual impairment (5 questions) and the surface impairment of the eye (3 questions) and the out of eye problems (3 questions). CONCLUSIONS: The visual fatigue questionnaire contains 15 questions and has a very remarkable validity and reliability. Using this questionnaire and its findings, one will be able to identify, assess and finally prevent the effective factors of VDT users' visual fatigue.

Effects of work-related stress on work ability index among refinery workers.

INTRODUCTION: Work-related stress is one of the basic problems in industrial also top 10 work-related health problems and it is increasingly implicated in the development a number of problems such as cardiovascular disease, musculoskeletal diseases, early retirement to employees. On the other hand, early retirement to employees from the workplace has increased on the problems of today's industries. Hereof, improving work ability is one of the most effective ways to enhance the ability and preventing disability and early retirement. The aim of This study is determine the relationship between job stress score and work ability index (WAI) at the refinery workers. MATERIALS AND METHODS: This is a cross-sectional study in which 171 workers from a refinery in isfahan in 2012 who were working in different occupational groups participated. Based on appropriate assignment sampling, 33 office workers, 69 operational workers, and 69 maintenance workers, respectively, were invited to participate in this study. Two questionnaires including work related-stress and WAI were filled in. Finally, the information was analyzed using the SPSS-20 and statistic tests namely, analysis of covariance Kruskal-Wallis test. Pearson correlation coefficient, ANOVA and t-test. RESULTS: Data analysis revealed that 86% and 14% of participants had moderate and severe stress respectively. Average score of stress and standard deviation was 158.7 ± 17.3 that was in extreme stress range. Average score and standard deviation of WAI questionnaire were 37.18 and 3.86 respectively. That placed in a good range. Pearson correlation coefficient showed that WAI score had significant reversed relationship with a score of stress. CONCLUSION: According to the results, mean stress score among refinery worker was high and one fator that affect work abiity was high stress, hence training on communication skills and safe working environment in order to decreses stress, enhance the work ability of workers.

Investigating the predictive of risk-taking attitudes and behaviors among Iranian drivers.

BACKGROUND: World Health Organization findings shows that up to year 2020 the number of fatality due to driving accidents will increases up to 65%, which is 80% is in developing countries. Iran has one of the highest rates of road traffic accident mortality rate in the world. MATERIALS AND METHODS: The cross-sectional study was carried out in the center and west of Iran upon 540 ordinary and taxi drivers who were driving regularly from bus terminals and the travel agencies to other cities. Data collection tool is a questionnaire that measuring driving risk taking by two items of risky driving behaviors and risk taking attitudes. FINDINGS: The results of this study showed that the averages of risk driving behaviors scores were higher than the average of risk taking attitudes scores. The results of logistic regression test showed that the risky driving behaviors can be a predictor of driving accidents due to individuals' risk taking (P = 0.014). Among all these variables, attitude toward rule violations and speeding, aggressive driving and violation of the road laws respectively are important predictive of drivers' risk taking (P < 0.0010). DISCUSSION AND CONCLUSION: Although attitude toward risk taking has been located at a low level by different ways, a desired result was not obtained from the reduction of those high risky behaviors; in fact, high-rate of accidents and traffic incidence in Iran indicates this matter well.

Evaluation of the effect of noise on the rate of errors and speed of work by the ergonomic test of two-hand co-ordination.

BACKGROUND: Among the most important and effective factors affecting the efficiency of the human workforce are accuracy, promptness, and ability. In the context of promoting levels and quality of productivity, the aim of this study was to investigate the effects of exposure to noise on the rate of errors, speed of work, and capability in performing manual activities. METHODS: This experimental study was conducted on 96 students (52 female and 44 male) of the Isfahan Medical Science University with the average and standard deviations of age, height, and weight of 22.81 (3.04) years, 171.67 (8.51) cm, and 65.05 (13.13) kg, respectively. Sampling was conducted with a randomized block design. Along with controlling for intervening factors, a combination of sound pressure levels [65 dB (A), 85 dB (A), and 95 dB (A)] and exposure times (0, 20, and 40) were used for evaluation of precision and speed of action of the participants, in the ergonomic test of two-hand coordination. Data was analyzed by SPSS18 software using a descriptive and analytical statistical method by analysis of covariance (ANCOVA) repeated measures. RESULTS: The results of this study showed that increasing sound pressure level from 65 to 95 dB in network 'A' increased the speed of work (P < 0.05). Increase in the exposure time (0 to 40 min of exposure) and gender showed no significant differences statistically in speed of work (P > 0.05). Male participants got annoyed from the noise more than females. Also, increase in sound pressure level increased the rate of error (P < 0.05). CONCLUSIONS: According to the results of this research, increasing the sound pressure level decreased efficiency and increased the errors and in exposure to sounds less than 85 dB in the beginning, the efficiency decreased initially and then increased in a mild slope.

Validation of a questionnaire for heat strain evaluation in women workers.

INTRODUCTION: Physiological, anthropometrical and thermal perceptual are the most important factors affecting thermoregulation of men and women in workplaces. The purpose of this study was determining the validity of a questionnaire method for assessing women's heat strain in workplaces. METHODS: This cross-sectional study was carried out on 96 healthy women. Data were continuously collected over a period of 3 months (July-September) in 2012. Mean ± (SD) of age was found to be 31.5 ± 7.48 years, of height 1.61 ± 0.05 m, of weight 61.55 ± 10.35 kg, and of body mass index 23.52 ± 3.75 kg/m(2) in different workplaces. Heart rate and oral temperature were measured by heart rate monitoring and a medical digital thermometer, respectively. Subjects completed a draft questionnaire about the effective factors in the onset of heat strain. After collecting the questionnaires, the data were analyzed by applying Cronbach'sa calculation, factor analysis method, Pearson correlation and receiver operator characteristic curves using the SPSS 18 software. RESULTS: The value for Cronbach's α was found to be 0.68. The factor analysis method on items of draft questionnaire extracted three subscale (16 variables) which they explained 63.6% of the variance. According to the results of receiver operator characteristic curve analysis, the cut-off questionnaire score for separating people with heat strain from people with no heat strain was obtained to be 17. CONCLUSIONS: The results of this research indicated that this quantitative questionnaire has an acceptable reliability and validity, and a cut-off point. Therefore it could be used in the preliminary screening of heat strain in women in warm workplaces, when other heat stress evaluation methods are not available.

Precise Evaluation of Anthropometric 2D Software Processing of Hand in Comparison with Direct Method.

Various studies carried out on different photo anthropometry, but each one had some deficiencies which during the years they have been resolved. The objective of this paper is to test the efficiency of two-dimensional image processing software in photo anthropometry of hand. In this applied research, 204 office workers and industrial workers were selected. Their hands were measured by manual with photo anthropometric methods. In this study, designing the "Hand Photo Anthropometry Set," we tried to fix the angle and distance of the camera in all of the photos. Thus, some of the common mistakes in photo anthropometric method got controlled. The taken photos were analyzed by Digimizer software, version 4.1.1.0 and Digital Caliper (Model: Mitutoyo Corp., Tokyo, Japan) was used via manual method. t-test statistical test on data revealed that there is no significant difference between the manual and photo anthropometric results (P > 0.05) and the correlation coefficients for hand dimensions are similar in both methods illustrated in the range of 0.71-0.95. The statistical analyses showed that photo anthropometry can be replaced with manual methods. Furthermore, it can provide a great help to develop an anthropometric database for work gloves manufacturers. Since the hand anthropometry is a necessary input for tool design, this survey can be used to determine the percentiles of workers' hands.

A Study on Work Ability Index and Physical Work Capacity on the Base of Fax Equation VO(2) Max in Male Nursing Hospital Staff in Isfahan, Iran.

BACKGROUND: The purpose of this research is to establish the ability of employees by work ability index (WAI), physical work capacity (PWC), and finding the correlation between them. Establishing the PWC index with attention to WAI values for the purpose of saving in costs and time of PWC measurements is another aim of this project. METHODS: The present research is an analytic cross-sectional and one-trail study. The study population consists of 228 randomly selected registered nurses from hospitals in Isfahan (Iran). The WAI and PWC were established through WAI questionnaire and Fax equation and by using ergometer bicycle, respectively. The resulting data were analyzed using SPSS 16 software. RESULTS: Average WAI and PWC among the study population were 38.25±4.4 and 4.45±0.7, respectively. Pearson test results showed no significant correlation between PWC and WAI in different age groups (r=0.3 and P>0.05). Multiple linear regression analysis showed that the variables of age and diagnosed diseases were the most effective factors of WAI (ß=0.18 and P>0.05). Pearson test revealed a significant correlation between the number of diagnosed diseases and PWC index in age groups of 40-49 years. CONCLUSION: Average WAI in this research, like other studies on similar jobs is in the acceptable level of >36. Work ability index and PWC index in different age groups did not show a significant correlation and this suggests that there are essential discrepancies in work ability evaluations made by each index and it is not possible to predict PWC index using WAI values. Given the PWC results and the level of nursing staff's activity (low, medium) the WAI is a suitable instrument to establish the professionals' abilities. This study revealed that 27.6% of individuals were subject to medium-low work ability risk (WAI<37), which was 1.8 times that of Finland's professional health Institute, which could be caused by shift working and increased working hours.

Evaluation of Work-related Psychosocial and Ergonomics Factors in Relation to Low Back Discomfort in Emergency Unit Nurses.

BACKGROUND AND AIM: High prevalence of low back pain is one of the most common problems among nurses. The aim of this study was to evaluate the relation of the intensity of low back discomfort to two low back pain contributor factors (Ergonomics risk factors and psychosocial factors). METHODS: This cross-sectional survey was conducted on 120 emergency unit nurses in Esfahan. Job content, ergonomics hazards and nordic questionnaire were used in that order for daily assessment of Psychosocial and Ergonomics factors and the intensity of low back discomfort. Nurses were questioned during a 5-week period, at the end of each shift work. The final results were analyzed with SPSS software18/PASW by using Spearman, Mann-Whitney and Kolmogorov-Smirnove test. RESULTS: There was a significant relationship between work demand, job content, social support and intensity of low back discomfort (P value <0.05). But, there was not any link between intensity of low back discomfort and job control. Also, there was significant relationship between intensity of low back discomfort and ergonomics risk factors. CONCLUSION: This study showed an indirect relationship between the intensity of low back discomfort and social support. This study also confirmed a direct relationship between the intensity of low back discomfort and work demand, job content, ergonomics factors (Awkward Postures (rotating and bending), manual patient handling and repetitiveness, standing continuously more than 30 min). So, to decrease work related low back discomfort, psychosocial factors should be attended in addition to ergonomics factors.