Iranian Journal of Ergonomics

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Background: The use of visual monitors especially in relation to computer can cause health effects which have negative impacts on mental and physical performance of users. This study aims to determine the relation between ergonomic conditions in use of visual monitors and subjective feeling of fatigue in master science students as permanent users. Methods: In this study, 40 students in the Hamadan University of Medical Scienceswere selected based onsimplerandomapproach. For determining subjective feeling of fatigue, the standard questionnaire with reliability coefficient equal to 0.8 was distributed and completed among students. This questionnaire has 30 questions which was covered three criteria included drowsiness, difficulty of concentration and physical impairment. The data about environmental and ergonomic conditions of the workstations was also recorded. Exposure to electromagnetic radiation in very low frequency was measured using instrument model HI 3603 front of the studied monitors. Data was analyzed with SPSS 16 software. Results: The results showed mean score of drowsiness, difficulty of concentration and physical impairment were 17.8±6.5, 18.7±4.4 and 11.9±6.9, respectively. Totally, mean score feeling of fatigue was 48.5±15.7. The relation between continuous work time and feeling of fatigue was significant (P<0.05).The relation between work day time and feeling of fatigue was not significant (P>0.05). The relation between type of used monitor and feeling of fatigue was significant (P<0.05). Moreover, the relation between environmental conditions of the workstations and feeling of fatigue was not significant (P>0.05). However, descriptive results showed growing trend of feeling of fatigue in unsuitable environmental and ergonomic conditions. Moreover, exposure to electromagnetic radiation between to type monitors was statistically difference (P<0.05). Conclusion: Criterion of difficulty of concentration was allocated the maximum score of feeling of fatigue which can cause negative impacts on educational performance. Compliance with the ergonomic principles especially reduction continuous work time and use of updated monitors and optimization of lighting and acoustic conditions of the workstations can reduce feeling of fatigue among students, considerably.

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This before-after clinical trial investigated the effect of daylight on morning and night melatonin, subjective general health using GHQ questionnaire, sleepiness and alertness on elderly who lived in nursing houses. Nineteen nursing home residents participated voluntarily. They exposed to daylight from 9 to 10 A.M. and from 4 to 5 P.M. for 6 weeks. General health of all participants was evaluated using general health questionnaire (GHQ) as well. Also we used of KSS and VAS questionnaire foe assessment of sleepiness and alertness. Baseline morning and night melatonin levels were 25.39 (±19.75)pg/ml, and 40.3 (±21.55)pg/ml respectively. Daylight exposure significantly affected morning melatonin at 7:00 A.M. but had no significant effect on night melatonin at 8:00 P.M. Mean score of general health changed 36.31 to 29.89 (P=0.003). Karolinska sleepiness scale (KSS) and Visual Analogue Scale (VAS) showed increase sleepiness and decrease alertness from 3:00 to 7:00 A.M. Sleepiness decreased and alertness increased during 1:00 P.M and 20:00 P.M. Overall day light exposure may delay sleep phase and circadian rhythm problems in elderly people. Anxiety and insomnia could be improved with daylight exposure. Our findings suggest that elders should be exposed to scheduled daylight in morning and evening for prevention and improvement of mental disorders. Adequate light should be provided for elder’s homes and nursing house. We have proposed to further study with a larger sample size be done to assess effect of daylight on GHQ' subscales.

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Introduction: Musculoskeletal disorders (MSDs) are the main causes of work related injuries and disabilities in developed as well as developing countries. Few studies have considered different interactive effects of individual and work-related factors on MSDs, simultaneously. Methods and Materials: Data were gathered by Nordic questionnaire and Quick Exposure Check (QEC) method and were analyzed using logistic regression model in order to study the correlation between the prevalence and intensity of MSDs and individual and work-related factors. Results: More than half of all participants (61.6%) reported suffering from one form of MSDs during the past 6 months. Results showed that risk factors such as work stress, sleeping position, lifestyle and poor posture had an important role in the prevalence and intensity of MSDs. Discussion: The effect of a risk factor is constantly in interaction with other risk factors, and is modified by other factors. Participatory ergonomic intervention programs, work station intervention, ergo stress intervention and life-style interventions were suggested in order to decrease the prevalence and intensity of MSDs.

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Introduction: Three methods of OCRA Index, Strain Index and ACGIH HAL are proposed to assess risk factors of upper extremity musculoskeletal disorders. These methods are important in work environments to evaluate musculoskeletal disorders. Thus the aim of this study is to determine the correlation between the results of the above mentioned methods. Materials and Methods: In this cross - sectional study, a total of 150 job tasks studied in four industries . For each task, not only video taping was used to record the duration of a full cycle but also tasks were evaluated according to instructions. The correlation coefficient and the coefficient of agreement were analysed using SPSS16 and R software. Results: Correlation between the results of risk assessment methods OCRA and SI for right and left hand, were acceptable correlation (0.751) and (0.726) respectively. Also the result of agreement between the methods OCRA and HAL for right and left hands, were (0.526) and (0.595) respectively. Conclusion: This study showed that none of the two methods do not fully agree. One of the source of differences is the number and types of variables and their effects on the final score of the methods.

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Introduction: Noise pollution cause mental fatigue, concentration disturbance and learning loss in students during the training activities. This study aims to evaluate Noise pollution and the level of acoustical comfort in typical classrooms, and present treatment methods for improving acoustic comfort. Method: In cross sectional study, twenty classrooms in the seven faculty of Hamadan University of medical sciences, were studied using questionnaire with reliability coefficient equal to 0.8 was completed among 413 students. Measurement of noise level was performed using sound level meter (model TES-1358) according ANSI S12.6 in classrooms. Result : The results showed the background noise level and outdoor noise level were equal 46.97 ± 3 dB(A), and 57.16 ± 4.8 dB(A) , respectively. The background noise was higher than the recommended limit equal to 45 dB(A) (P<0.01). The construction activities are most important annoying factor and concentration disturbance are most complication of noise. Signal to noise ratio within the classroom was 13.14±3.54 dB (A), which was inappropriate compared with the recommended limit 15 dB (A) (P<0.01). The difference in speech intelligibility at various levels of signal to noise ratio was significant (p<0.05). Conclusion: The results confirmed the studied classrooms haven’t acceptable acoustic conditions and background noise level was affected by outdoor noise. In regard to confirmation of the effects of noise on the student attention, the acoustic interventions is must be considered.

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Background and aim: the workers in Quarry and Stone Industries done frequently some duties including lifting and carrying of heavy loads and they are exposed to high risk of cumulative trauma disorders. The aim of this study was to comparing the prevalence of musculoskeletal disorders and risk of work postures in Quarry and Stone Industries workers. Material and methods: this cross-sectional and analytical study was done on 63 workers of Stone Industries and 46 workers of Quarries in Kermanshah. Data were collected using by Nordic standard questionnaire, Body map chart and REBA method. The gathered data was been analyzed by Independent t-test, Mann-Whitney, Spearman and Pearson tests. P was 0.05. Results: The most prevalence of musculoskeletal disorders in both Stone and Quarry industries was related to low back that was 54% and 39% respectively. Mean and standard deviation of final scores of REBA in Stone and Quarry workers were 9.06±1.45 and 4.6±1.18 respectively. Results shows that a significantly correlation between age, work history and BMI with musculoskeletal disorders in Stone Industries and between age and work history with this disorders in Quarries (P<0.05). Conclusion: the results shows that the risk level of REBA and prevalence of musculoskeletal disorders of Stone Industries was more than Quarries in shoulder, wrist, hand, lumbar, femur, knee, leg and ankle.

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Introduction: The maximum aerobic capacity (VO2-max) can be used to assess the cardio-respiratory condition and fit the physiological characteristics of workers to the work. This study was conducted to determine the correlation between the two methods of estimating the maximum aerobic capacity and its affecting factors among students of Shiraz University of Medical Sciences.

Materials and Methods: In this cross-sectional study, 104 students (54 males and 50 females) participated voluntarily (age ranged from 18 to 28 years). The subjects were assessed by step test according to Åstrand and ACSM protocols. The data collecting tool was a questionnaire including separate sections of demographic (age, sex, etc.), anthropometric (height, weight and BMI) and physiological (VO2-max) characteristics.

Results: The results revealed that the maximum aerobic capacity estimated from Åstrand and ACSM protocols were 3.21 (0.825) and 3.13 (0.707) l.min-1, respectively. Pearson correlation test showed high correlation between estimated maximum aerobic capacity via two protocols of Åstrand and ACSM (r=0.958). Meanwhile, there were significant associations among maximum aerobic capacity with weight, height, BMI and the number of hours of exercise per week.

Conclusion: The two methods for estimating the maximum aerobic capacity (Åstrand and ACSM) were highly correlated. Variables such as weight, height, BMI, and number of hours of exercise per week can be named as effective factors on VO2-m Normal 0 false false false EN-US X-NONE AR-SA

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Introduction: Bank staff experience high level of job stress due to the nature of their work. One of the consequences of stress is its impact on job performance. Since the internal studies in this area are relatively rare, this study was conducted to investigate the relationship between the psychosocial stressors and job performance among bank staff. Materials and Methods: All staff of the bank branches participated in this study. The General Nordic Questionnaire and Human Resource Productivity Questionnaire were used for data collection. The correlation coefficient and regression models were employed to examine the relationship between job stressors and their scales as independent variables and job performance as the dependent variable. Furthermore, in order to accurately assess the relations between variables, structural equation models were utilized. Results: The results revealed that the prevalence of stress among bank staff was in moderate level (46.6%). Meanwhile, there was a negative and significant relationship between stress in "task domain" and "socio-organizational domain" and job performance. Among the measures in socio-organizational domain, organizational culture and leadership showed highly negative and significant relationships with job performance (p= 0.001). Conclusion: According to the obtained results, socio-organizational domain can be considered as the main cause of loss of productivity. Hence, it is suggested to make further attempts to control the psychosocial factors in workplaces and avoid performance deterioration, particularly in organizational culture and leadership measures.

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Introduction: Regarding the increasing growth in jobs dealing with computers and the development of musculoskeletal disorders (MSDs) among VDT users, the assessment and identification of ergonomic risk factors are of greater importance. This study aimed to evaluate MSDs among office VDT users.

Materials and Methods: This cross-sectional study was conducted on 71 participants (37 females and 34 males) selected randomly among administrative staff of Isfahan Art University. CMD questionnaire was used to assess the prevalence of MSDs and for measuring ergonomic risk factors ROSA method was employed in VDT stations.

Results: According to ROSA risk levels, 21% (15 participants) were at low risk (score of less than 3), 48% (34 participants) were in the notification area (score 3 to 5) and 31% (22 participants) were in the need area for ergonomic intervention (score of more than 5). Sex, body mass index, educational level and work experience had significant impacts on ROSA final score (p<0.001). There was a positive significant correlation between ROSA final score and MSDs in the participants (p<0.001, r=0.828).

Conclusion: With regard to the purpose of ROSA method for evaluating risk factors of working with computer in administrative and office settings and the finding of this study, it can be employed as a useful tool in identifying and ranking ergonomic risks in today office environments. Normal 0 false false false EN-US X-NONE AR-SA

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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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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.