Iranian Journal of Ergonomics

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Introduction: Musculoskeletal disorders (MSDs) are common consequences of poor working conditions associated with computer use. Regarding the lack of information about MSDs and the extensive use of computer among the university students in our country, this study aimed to explore the awareness level of ergonomic considerations in computer use and the prevalence of MSDs among university students.

Materials and Methods: This cross-sectional study was conducted on 450 students of three faculties of medicine, dentistry and paramedical of Babol University of Medical Sciences in 2012. The subjects were selected by simple sampling method. The data were gathered by the researcher-made questionnaire consisting of 6 open and 10 closed questions. Data processing was performed by using descriptive statistics and chi-square test.  

 Results: The mean (SD) age of students was 21.7 (2.5) years, 64% were females and 67% were undergraduate students. Ninety percent of the students had personal computer and 48% had spent 1 hour or more on their computer daily. It has been reported that approximately 55% of students had suffered from MSDs and less than 10% of them had been familiar with ergonomic considerations in computer use. Chi-square test indicated a significant difference in the incidence of MSDs in terms of the duration of working with computer (p<0.05).

 Conclusion: The complaints of MSDs in about half of the students and the lack of awareness of ergonomic considerations in most of them suggest the possibility of increasing future problems. Therefore, regarding the inclination of most students in receiving information and their influential role in the dissemination of knowledge, performing interventional programs including education in computer ergonomic principles is recommended.   Normal 0 false false false EN-US X-NONE AR-SA

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Introduction: Due to the increase of public concern about the physical and psychological effects of radiation on the health of users, the present study aimed to determine the extent of public exposure to microwave emissions from wireless system in an educational setting.

 Materials and Methods: In this cross-sectional study, the effective intensity of microwave radiation were measured in 110 stations including the location of antennas access points, inside the classrooms, corridors and next to computers in five faculties of Hamadan University of Medical Sciences. Microwave meter HI 2200 model made by Holaday Co. was used to measure radiation according to the standard method No. C95.3. 

Results: The effective intensity of exposure to microwave radiation emitted in the studied university was equaled to 0.304±0.675 µW/cm² which was lower than the international exposure limits. However, there were significant differences in the intensities of microwave radiation in terms of measurement locations (P=0.0001). The Highest intensity of microwave radiation was allocated to access points which were equaled to 1.731±0.214 µW/cm².

 Conclusion: Although the intensity of microwave exposure from wireless networks at the university level was lower than the international limits and due to the failure to obtain conclusive evidence on the health effects of radiation exposure on humans at various levels, it seems to be necessary to inform users about radiation health risks to increase their awareness in educational settings.  Normal 0 false false false EN-US X-NONE AR-SA

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Introduction: Working with Visual Display Terminals (VDTs) can be associated with visual complaints particularly visual fatigue and symptoms including headache, disruption in continuing the work and ocular disorders. The objective of the present study was to determine the prevalence of visual fatigue and its related risk factors in computer users of Kermanshah University of Medical Sciences in 2013. Materials and Methods: This descriptive-analytical study was achieved on 260 computer users. The data were collected by Visual Fatigue, demographic and job questionnaires. For data analysis, Spearman, Mann-Whitney and Kruskal-Wallis tests were used. Results: The mean (SD) age of the users was 36.74 (7.74) and daily working time with VDTs was 5.85 (2.28) hours. Visual fatigue score was 2.99 (1.97), so that 32.3% of computer users had severe eye fatigue. Meanwhile, 45.4, 21.9, 32.7 and 46.2 percentage of users suffered severely from eye strain, visual impairment, eye-surface disorder and extra-ocular problems. Visual fatigue incidence and its compliments were significantly increased with increasing of age, work experience and daily working hours with computer (p<0.05). Visual fatigue was higher in users wearing glasses than those not wearing glasses (p<0.001) and was lower in monitor to window angle of 90º than two other monitor to window positions of 0º (p=0.041) and 180º (p=0.036). Conclusion: The prevalence of visual fatigue among computer users was very high. Visual fatigue and its serious consequences can be prevented by applying the principles of ergonomics such as regular and short breaks, looking at distant objects, blinking regularly and reducing the direct and indirect glares.

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Background: Shift work is one of the inevitable consequences of technology in which in the recent years numerous studies have been done about its effect on health. Somatic, psychological and social disturbances are among the problems that are seen more in people with shift work than other people. The current study aims to determine the prevalence of these disturbances in one of the LPG and gas refinery complex, oil companies. Methods: This cross-sectional case-control study was carried out at 180 shift-work people as case group and 90 day-work people as control group at the security section of the oil refinery company. Data of shift workers were collected with Survey of Shift workers (SOS) questionnaire. The questionnaire consisted of questions on demographic characteristics and health problems associated with shift work. Statistical analyses were performed using SPSS Ver.19 at a significance level of 5%. Results: The mean (SD) of shift working and day-work workers were estimated to be 41 ± 4.8 and 39 ± 4.1 years, respectively. The results showed that health problems shift-workers were more prevalent than day-work workers. The differences were significant in gastrointestinal disease, cardiovascular disease, hypertension and fatigue (P < 0.05). Conclusion: According to the result of this study, shift work can be a risk factor for the incidence of somatic and psychological disturbances. Initiatives should be implemented to prevent these complications in shift workers.

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Introduction: Many calls already perform by cell phones that have need to radiation exposure by users. Because of health reasons and some doubts about effects, this study was conducted to determine the extent of the mobile phones radiations and self report symptoms of users. Material and Method: In this cross-sectional study, 80 available randomly users contain students and staffs of Hamadan University of medical sciences in 2012 were selected. Electro Smog meter TES-593 was used as radiation measurements tool. In order to assess health effects of mobile phones’ radiation, a self-administered survey questionnaire were used. Statistical analyses were performed using T-test, ANOVA and X2 tests by SPSS 11.5. Results: Results showed that the conversation mode had a highest level of electromagnetic indices in the studied cell phones. Compare means of power density that emitted from studied mobile phones had significantly difference (P=0.001). Relationship between exposure to the mobile phones radiation by symptoms of head-ache, anxiety and sleep disturb were significant (P=0.02, P=0.03, and P=0.002 respectively). Conclusion: Although, there is founding the relations between exposure to cell phones electromagnetic fields and some self-reported symptoms in line with same reports, These symptoms can not be absolutely attributed to the use of mobile phones. With these considerations it is recommended that for prevention of health risks from cell phones, safe type selection, control of call duration and frequency of use of these devices should be mentioned.

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Introduction: The development of the industry has led to an increased incidence of muscle-skeletal disorders. The disorders increased caused by factors such as type of job, repetition of work, intensity and duration of the work. Food industries, including industries that are doing the type of job that involves repetitive movements, this study examined was conducted the role of stress and other psychosocial factors on musculoskeletal disorders. Methods: The present cross-sectional study to determine the prevalence of musculoskeletal disorders in different organs and factors affecting food production was one of the workers. According to a random sample of 215 workers were studied with an average age of 39 years. To evaluate the prevalence of musculoskeletal disorders was used of the Nordic questionnaire, also for of occupational stress was used OSIPOW questionnaire the data obtained are analyzed by SPSS 16 software and processing of data with the descriptive statistics and Pearson correlation test. Results: The results showed that the study population in the past 12 months the most common symptoms of lower back 69.8%. We were founded between stress and musculoskeletal discomfort in the neck, shoulder, wrist, upper back, a significant relationship (P<0.05). We were founded between smoking and low back pain (P <0.05), shoulder pain (P = 0.023), leg pain (P = 0.008) statistical test significant. As well as we were found between the average working hours per day and work experience, with musculoskeletal symptoms, fatigue, and BMI also a significant relationship. Conclusions: The results obtained in this study shows that job stress, work experience, BMI, the number of working hours and fatigue is considered a risk factor for upper extremity musculoskeletal disorder.

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Match between school furniture dimensions and children’s anthropometric dimentions in male elementary schools. Rashid Heidari Moghaddam1, Rasoul Ahmadi2 , Majid Motamedzade3, Ghodratollah Roshanaie4 stract: Introduction: Given the important role of appropriate furniture in the posture of the students and that non ergonomic furniture can produce uncomfortable posture, low ‌‌‌back pain, neck pain, lack of concentration and discomfort, therefore, this study examine match between school furniture dimensions and children’s anthropometric dimensions in male elementary schools in Hamadan city. Materials and Methods: In this study 600 children have been studied. Their weight and height and their anthropometric dimensions included shoulder height, elbow height, knee height, popliteal height, popliteal-bottock length and hip breadth have been measured. Then, the fitness between current furniture's dimensions and calculated ergonomic dimensions have compared. Results: : Findings showed that dimensions of available furniture included seat height, seat depth, seat width, back rest height, desk height, underneath desk height and anthropometric dimensions of students was not matched. This study has shown that by increasing the seat depth and decreasing the seat height in new designs, they have relatively improved in compare with the old designs. Conclusion: Available school furniture dimensions in Hamadan elementary schools are not appropriate for most students and induce postural discomfort and musculoskeletal disorders. Key words: Ergonomics, Anthropometrics, Design, Furniture 1- Department of Ergonomics, Faculty of Health and Medical Sciences Research Center, School of Public Health. Hamadan University of Medical Science, Hamedan, Iran. 2- Corresponding author, Ergonomics graduate student, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran. 3- Professor, Department of Occupational Hygiene, School of Health and Research Center for Health Sciences, Hamadan University of Medical Sciences, Hamadan, Iran. 4- Roshanaei, Ghodratollah, Department of Biostatistics and Epidemiology. Modeling of Noncommunicable diseases Research center, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran.

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Background: Psychosocial factors are present in most workplaces that could affect various aspects of workers’ health. Accordingly, psychosocial risks may lead to work related musculoskeletal disorders, increased risk of cardiovascular disease, effect on quality of working life, sickness absence, depression work injuries and accidents and various health problems. The aim of the present study was to assess work psychosocial problems and their association with non-fatal occupational accidents among Aghmary workers of Iranian drilling rigs. Methods: A cross-sectional study using the short version of the Copenhagen Psychosocial Questionnaire (COPSOQ) was carried out on a total sample of 270 employees working on Aghmary system in drilling rigs. History of non-fatal occupational accidents was assessed by self-report during one year prior to the study. Statistical analyses were done using SPSS 16.0. Results: The results showed that high work pace (OR=1.55), high emotional demands (OR=1.62), high influence at work (OR=1.5), low quality of leadership (OR=1.8), low social support (OR=1.87), high burnout (OR=1.72) and high threat of violence (OR=6.2) were significantly related to non-fatal occupational accident. Conclusions: This study revealed the significant association between occupational accident and some psychosocial dimensions and recommended the incorporation of psychosocial factors in preventive measures.

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Background: One of the main problems in the occupational workplace is musculoskeletal disorders. Quality of life is a multidimensional concept, including the ability of performance, health and mental statues that important factors such as physical, psychological, social relationships and personal attitude influence on quality of life .The aim of current study is assessment of impact of musculoskeletal disorders and physical activity on quality of life in automobile factory workers. Materials and Methods: In this study, from 453 automobile factory workers, 140 workers participated. In order to determine musculoskeletal disorders, quality of life and physical activity, Nordic musculoskeletal questionnaire, quality of life questionnaire (SF 36) and physical activity questionnaire were used respectively. Data were analyzed using SPSS-16 software with descriptive analysis and Pierson correlation analysis. Result: The results showed that the between physical function, activity limitation due to physical problems, bodily pain, vitality, public health and fatigue with musculoskeletal disorders were statistically significant correlation (P< 0.05). Between regular physical activity and musculoskeletal disorders and consequent with quality of life obtained significant correlation. Discussion: Physical activity (exercise) increases worker fitness and reduces probability risk of musculoskeletal disorders and increase quality of life.

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Background: Adverse events are injuries and problems are derived from management than the original condition. In particular, Intensive care units are as a place of significant human errors and preventable adverse events in the health care system. The present study was conducted to identify and evaluate human errors among cardiac intensive care nurses in a teaching hospital in Hamadan city. Materials and Methods: This qualitative study was conducted using the cream technique. in this study nursing job were analyzed using hierarchical task analysis. Then the work sheet of cream techniques completed through observation and interviews with the nurses. Data analysis was performed using spss-16 software. Results: Findings show that the maximum probability of error are in setting tasks and use DC shock in urgent cases, data recording in the hospital system, said start code resuscitation of heart and lung (CPR) respectively 0.02108, 0.02088 and 0.02086. Minimum probability of error were Determine nutritional needs and diet, gavages and necessary care and giving oral medications respectively 0.01100, 0.01013 and 0.00966. Conclusions: The most important suggestion to improve of working situation and reducing of human error probability are modification of nurses shift work, providing of practical training and decrease of additional duties.

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Background & Objectives: Shiftwork is a social phenomenon that can have adverse effects on human life. Given the importance of the shiftwork system and caused by the related health problems, the present study was conducted to determine the health status of and shift workers in a hospital. Methods: This cross-sectional study was conducted in one of the hospitals in Razan (Iran). The sample size consisted of 120 medical, administration and service staff. The SOS questionnaire was used for data collection. The data analysis was performed in SPSS software by χ2. Results: The results showed that 98.3% of complaints were about personal, social and familial problems, and 84.9% were related to musculoskeletal disorders. . Satisfaction of rotating shift work and shift work voluntarily chosen variables, the rotation of the shift, shift work and adverse effects on personal life, adverse effects on family life revealed a significant relationship (P<0.05). Instead, insomnia common variables, adverse effects on social life and social problems showed no significant relationship.

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Background: Patient Manual handling is one of the major risk factors in musculoskeletal disorders among healthcare workers (HCWs). Therefore, the purpose of this study was to estimate the mechanical force on the low back of the staff responsible for patient manual handling and to exam in the effect of patient manual handling by two people on the level forces exerted on HCWs ҆ low back. methods: the participants of this study were 10 health care workersdoing patient manual handling individually and by two people . To determine the posture of these people, we filmed them both from front and side and force plate was used to determine the weight of the patient handling by HCWs. 3DSSPP was used to estimate theforces exerted on the their low back during patient manual handling. Results: Results showed that among the four studied tasks, the maximum compression forces exerted on discs L4/L5 and L5/S1 were 3591 ± 863 and 3342 ± 827 respectively when the patient was seated on wheelchair. The Maximum shear force exerted on the disc L4/L5 and L5/S1 were 252 ± 122 432 ± 36 N respectively when patient was seated on the bed. No significant difference was seen in the average forces exerted on low back except seating patient on wheelchair. ( P> 0.05) Conclusions: The comparison of exerted force on disks with recommended limits revealed that only the task of placing patient on wheelchair exerted force on low back exceed NIOSH recommended weight limit. patient manual handling by two people most tasks of this study does not created significant difference. Therefore to reduce exert force on low back need ergonomic intervention including bed design, beds appropriate stabilization, training.

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Introduction: Musculoskeletal disorders are the most common occupational diseases and injuries. The importance of control and reduction the discomfort to the extent that in many countries, Prevention of work-related musculoskeletal disorders among workers has been considered as one of the national priorities. Methods: the cross-sectional study was carried out as an intervention in a chicken slaughterhouse. In order to determine the prevalence of musculoskeletal disorders, Cornell questionnaire was used. By identifying the tasks that are very high in musculoskeletal disorders posture evaluate was conducted and then the proportional to risk level tasks, engineering and management measures was performed. Given that most tasks are the kind of manual handling and carrying, were used the KIM methods for evaluating posture before and after of intervention. Results: The results of the Cornell questionnaire showed that the highest risk level Belongs to the neck, shoulders, back, arms and waist. Also evaluate by the KIM method the highest level of risk was estimated, the task of throwing the box and pick up the ice with the risk level 4 score, that after the intervention, decreased to the 2 score. Improvement obtained for all interventions on the average about 46.37 percent. The McNemar test was also significant difference between the results obtained before and after intervention. Conclusion: ergonomic problems have undesirable effects on employee health and productivity. This study, engineering and management interventions could significantly reduce the amount of corrective measures to improve working conditions in different parts of the company.

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Background: The purpose of present study was to evaluate the effects of six- week aerobic step training on cardiovascular fitness, body composition, flexibility, leg anaerobic power and quality of life of isfahan university female students in academic year 2012-2011. Methods: 31 female students of Isfahan university were randomly assigned in experimental group (N=16, mean Age 27±2 , Weight 58.34 ±6.27, Height 1.61±4) and control group (N=15, mean Age25 ±1 , Weight 54.7±7.32, Height 1.61±6).pre test and post test measurements included cardiovascular fitness, body composition, flexibility, leg anaerobic power and quality of life questionnaire(WHOQOL(. analysis of covariance( ANCOVA) was used to test to effects of aerobic training as intervention(P<0.05). Results: There was a significant increase in cardiovascular fitness (p=0.001) and there was a significant decrease in body composition (p=0.046). There was no significant increase in flexibility (p=0.109) and leg anaerobic power (p=0.180). there was a significant increase in total score of quality of life(p=0.00). Conclusion: a six- week aerobic step training improves quality of life and cardiovascular fitness and body composition of training group

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Background: Safety signs are considered as visual intermediates for message transmission and play a crucial role in reducing accidents particularly in petrochemical industries. These signs are effective as long as they are designed in compliance with ergonomic principles, human factors, and cognitive features. Therefore, the present study aimed to investigate the psychological effects of safety signs in transmitting message given their designing features in the petrochemical industry. Materials and methods: This descriptive-cross-sectional study was carried out on 100 employees in Mahshahr Petrochemical Complex. A 2 partite questionnaire was used to collect data the first part for demographic information and the second part included designing features of signs (familiarity, objectivity, simplicity, meaningfulness, semantic proximity). The Pearson correlation test was used to identify the correlation coefficients between signs features and scores given by the participants. Findings: Mean and standard deviation of the scores of the signs’ message perception were 60.73 and 4.36, respectively. Cognitive features of the signs included familiarity and semantic proximity with a mean of 49.15 and 66.78, respectively. The factors of work experience, age, and academic level had no significant effect on guessing the meaning of signs (p>0.05). Conclusion: The results of this study showed that no significant relationship existed between cognitive features of the signs and transmission of the message and message transmission of safety signs is affected by other features than their design. Therefore, in order to improve individuals’ awareness about familiarity of employees with particular meaning of signs, ergonomic design of safety signs and proper training for perceiving their meaning are proposed.

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Abstract Background: Heat exposure is one of the harmful agents at work environments. Workers in high temperature environments are susceptible to heat strain. The purpose of this study was to evaluate the performance of Iranian cooling vests containing phase change material in hot and humid conditions in the Persian Gulf. Materials and Methods: This interventional study carried out on 6 subjects of oil tanker ship's engine room staff in summer in 2013. The Heat Strain Score Index (HSSI), oral temperature and blood pressure measured with and without the cooling vest wearing for two hours, and data were analyzed by paired t test. Results: The mean oral temperature were 36.98± 0.22 °C (without cooling vest) and were 36.68± 0.68°C (cooling vest) at 30th minutes in heat exposure. The mean oral temperature were 37.06± 0.25 °C (without cooling vest) and were 36.78± 0.16°C (cooling vest) at 60th minutes in heat exposure. (p <0.042) and also HSSI was 12.72 ±3.03 (without cooling vest) and 8.65 ±2.9 (with cooling vest) (p <0.039) but the mean systolic and diastolic blood pressure were not significant statistically with and without the use of cooling vests (p>0.05). Conclusion: Our findings showed that cooling vests with phase change material packs reducing heat strain (oral temperature and perceptual heat) in hot and humid climates in Persian Gulf

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Background: Nurses’ Burnout can lead to increasing absenteeism and also decreasing energy and quality of service that provided by them. The aim of this study was to determine the prevalence of occupational burnout and its related factors among nurses of a hospital in Kermanshah city in 2013. Materials and Methods: In this cross-sectional and descriptive-analytical study 189 nurses were selected randomly. Data were collected by demographic questionnaire and Maslach Burnout Inventory (MBI). The gathered data were analyzed by Pearson, Independent T-test and ANOVA in statistical level of p≤0.05. Results: Mean score of occupational burnout was 61.89. 39.2% nurses reported high emotional exhaustion, 37.6% high depersonalization and 73.5% of them had low personal accomplishment. There were statistical relationship between emotional exhaustion with employment status (p=0.015) and educational degree (p=0.041), between depersonalization with employment status (p=0.022) and working shift (p=0.023), and also between personal accomplishment with age (p=0.010), working experience (p=0.002) and shift working (p=0.045). Conclusion: The level of nurses’ occupational burnout was average to high. The causes may be high workload, unsafe and boring work environment and high stress. It can be increased the commitment, positive sense to work and personal accomplishment can be reinforced by correct management of human resources including the determination of duties and strategies according to nurses’ ability, new approaches for encouragement and motivation as well as running stress management workshops.

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Introduction: Index of usability evaluates performance, user satisfaction and increased productivity in a product. Principles of usability are effectiveness, efficiency, safety, utility, learnability, Memorability. This Study Aims to Develop a Tool to Estimate and Evaluate the Usability of Web Applications in the field of Automation Research has been determined.

Material and Methods: After extracting, an initial questionnaire to assess the usability of the standard resource for indices of validity, internal consistency and reproducibility, respectively technique for determining the content validity, test-retest method and cronbach's alpha coefficient were used. The most important steps were as follow: (1) determine the scope and dimensions of the questions (2) preparing draft questionnaire (3) appoint the members of the expert panel (4) methods, how data analysis (5) determine the acceptance criteria of the questions (6) determine the content validity index (7) determine reliability of the questionnaire (8) determine reproducibility of the questionnaire.

Results: A 50-Item questionnaire was designed as the ultimate tool. The content validity index value of 0.763 was obtained ultimately for the questionnaire. Analysis of the questionnaire responses revealed that the lower backend errors related to the reliability coefficient alpha value was equal to 0.742. Finally, the degree of reproducibility of the questionnaire, using test-retest method, was equal to value of 0.993 (p <0.001).

Conclusion: After the final questionnaire design, with good reliability and validity, it is noticeable that the designed tool is applicable on relevant softwares and may improve the quality and efficiency of the software and user interface.

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Introduction: One of the most important subjects in the analysis of driver’s behavior had been situation awareness during the past decade. However, no study has been investigated the relation among component of situation awareness and performance and cognitive abilities of bus drivers. Current study aimed to survey relationship between bus drivers’ situation awareness, driving performance and cognitive abilities using driving simulator.

Material and Methods: In this study, 30 professional bus drivers who have diploma or higher degree participated. Situation awareness measured by SAGAT technique and tests UFOV, EFT and WMS were used for measuring of cognitive abilities. Brake reaction time and lane departures were criteria for driving performance.

Results: Accordingly, the result showed significant relation between drivers’ situation awareness before and after hazard conditions. Among WMS, divided attention, selective attention and EFT with level 1 of situation awareness was seen significant relation. The result of current study released a significant correlation among WMS and divided attention with lane departure.

Conclusion: Results showed, in general, the driver's situational awareness in dangerous conditions increases. The study showed that cognitive ability affects only level 1 of situational awareness. According to role of situational awareness in driving performance, the results of lane keeping showed that perception might be a key factor in driving performance.

        

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Introduction: In many sensitive and sophisticated workplaces, human errors are very important. Many events occur annually around the world is evidence to confirm error due to the data processing operators. The main goal of this study was to investigate human information processing models and workload demands on human operators, then developing a regression model for this purpose.

Material and Methods: This was a case study. Task analysis of control room members, including shift supervisor, board man, and site man and user instrumentation in this study was investigated. Data collection was performed by interviewing employees using a questionnaire with two parts the first part was the model of human information processing and the second part was workload NASA–TLX and an appendix of opinions existing staffing level and finally task analysis performed using SPSS 16 – SPSS.

Results: There was a correlation between workload and stages of human information processing model such as perception )r=0.65, p<0.01), vocal response (r=0.45, p<0.01) and manual response (r=0.15, p<0.05). Some effective factors on workload were vocal response (β=0.232, p=0.033) and perception (β=0.576, p=0.00). The most important factors in the analysis of anticipation staffing demand were perception (β=2.514, p=0.008), workload (β=1.57, p=0.018) and vocal responses (β=2.428, p=0.01), respectively.

Discussion and Conclusion: Increasing concentration and attention and perception skills using psychological measures including decreasing the workload and stress and holding specialized training courses are necessary.