Search

Introduction: Musculoskeletal disorders (MSDs) have a multifactorial nature. Biomechanical factors are one of the most important factors. Consequently, the precise identification of effective factors plays a significant role in controlling and preventing these disorders. Therefore, the current study aimed to identify the awkward upper body postures and their effect on the prevalence of MSDs in office workers in both women and men groups by objective methods. Material and Methods: In this cross-sectional study, the participants were 36 office workers (18 women and 18 men). The prevalence of musculoskeletal discomfort was evaluated using the Nordic questionnaire. The upper limbs posture, including the back, neck, and wrists, was evaluated continuously with an electronic inclinometer and an electrogoniometer for 30 min, followed by analyzing the collected data. Results: The results revealed that the highest prevalence of musculoskeletal symptoms in both gender groups was in the neck (58.33%), trunk (52.77%), and wrist (47.22%), respectively. The results disclosed that the median trunk and neck flexion in both groups is over 20° and the posture angle in women is higher than that of men (P

Today, Phased Array Ultrasonic Testing (PAUT) is a suitable method for detecting defects in Non-destructive Testing (NDT). This simulation was done with a new method on a stainless steel pipe with a diameter of 500 mm and a length of 1,000 mm, and cracks were modeled on the external and internal surfaces and corrosion defects on the internal surface. Four probes with a characteristic of 2 MHz were used simultaneously, each probe having 64 elements. By increasing the number of probes and their elements, more accurate information about the defects is obtained, which makes it easier to detect the location and leads to a reduction of scattered signals and noise, which can detect even small size defects. Considering this important advantage, a new use of the method of increasing the number of probes in PAUT is reported in this study to detect defects, especially corrosion defects. The results of geometric anisotropy studies of group velocity and phase of horizontally polarized shear waves (SH-waves) for stainless steel pipe were presented. Due to the isotropic properties of the pipe material, the speed on the outer surface of the pipe in the direction of the cover is 40 m/s higher than the generatrix.

Introduction: Occupational back pain is one of the musculoskeletal disorders (MSDs) caused by manual load-lifting among women involved in manual lifting activities. Limits for lifting loads are used to assess the risk and prevention of occupational back pain. The Washington Industrial Safety and Health Act (WISHA) checklist is used as a permissible load assessment limit in Iran. The present study aimed to evaluate the reliability of using the WISHA checklist to determine the allowable limits of manual load-lifting among women based on biomechanical and psychophysical methods. Material and Methods: In this study, ten women workers aged 20-30 years with a history of manual load-lifting were asked to perform 21 load-lifting tasks designed according to the permitted limits of Iran. A wireless electronic clinometer was used to determine the flexion angles of the trunk while lifting the load. Anthropometric information, load weight, trunk angle, and posture were entered into 3DSSPP software to obtain biomechanical forces for each task and compared them with the recommended National Institute for Occupational Safety and Health (NIOSH) limits. After performing each task, the rate of perceived exertion of each person for each task was collected by using the Borg scale. Results: The flexion angle for 47.61% of the lifting tasks were more than 20 degrees. The estimated average compressive force for the six tasks exceeded NIOSH’s recommended limits. The average Borg scale was determined hard for 33.33% of lifting tasks and hard to very hard for 9.52% of tasks. Conclusion: It was found that the manual load-lifting standard for some tasks might not be sufficient to control and prevent low back pain caused by manual lifting in women, and some non-compliance was found with the allowable lifting limits. Manual load-lifting with anthropometric and biomechanical features may increase the biomechanical force on the women’s low back. Therefore, it seems that the allowable lifting limits of Iran for women based on the WISHA checklist should be reviewed and redesigned based on anthropometric and biomechanical characteristics.

Introduction: Manual Material handling includes activities in which pushing, pulling, lifting, lowering, carrying, and holding the load, the most common of which is lifting. This study aimed to evaluate the reliability of the KIM-LHC method to identify high-risk manual load lifting tasks. Material and Methods: This cross-sectional study was performed on healthy male workers with a history of manual material handling in a laboratory setting. The sample size was determined according to previous studies of 15 people. The participants were required to perform 25 tasks with four iterations randomly. An inclinometer device was used to determine the forward bending angle at the waist. Compression loads exerted on L5/S1 were estimated using 3DSSPP software using participants' postural and anthropometric information. Also, the tasks were evaluated using the KIM-LHC method, and their final scores and levels of MSD risks were determined. Data were analyzed using SPSS.20 software and the Chi-square test. Results: The results of compression load estimation for lifting tasks showed that 92% of the tasks had a low-risk level (less than 3400 N), and 8% of the tasks had a medium-risk level (3400 to 6800 N). While the results of the KIM-LHC method showed that 28% of tasks had a low-risk level, 64% had a medium level, and 8% had a high-risk level. Conclusion: The results of this study showed no correlation between the risk levels of the KIM-LHC method and the estimated compression load for some designed lifting tasks. Therefore, there is a possibility of error in estimating the risk level of some lifting tasks by the KIM-LHC method, and more biomechanical studies should be performed on kinetics and kinematics.

Introduction: Work-related musculoskeletal disorders are the most common and costly preventable occupational problem that office workers suffer from the discomfort associated with these disorders. The aims of this study were to a) investigate the prevalence of low back pain (LBP) and b) continuously assess the trunk postures of office workers .Materials and Methods: Thirty-six office workers of a medical university participated in this cross-sectional study. Thirty-six office workers of a medical university participated in this cross-sectional study. The prevalence of LBP was determined using the Nordic Musculoskeletal Questionnaire. Work trunk postures were measured using an inclinometer. Results: More than half of the subjects reported LBP. There was a significant relationship between LBP with age, work experience, working hours, and gender (p

Background and Objective: Work-related musculoskeletal disorders are among the most common types of occupational diseases. This study aimed to investigate the relationship between lifestyle and mental workload components with the prevalence of musculoskeletal disorders in employees working in the automotive industry. Materials and Methods: This cross-sectional study was conducted on 303 employees working in a car manufacturing complex in Iran. The required data related to demographic characteristics, the prevalence of musculoskeletal discomfort, lifestyle, and mental workload were collected using demographic, Cornell, Walker health-promoting lifestyle, and NASA-TLX questionnaires, respectively. Results: According to the results, 70.70% of the participants experienced musculoskeletal disorders in at least one of their organs. Moreover, musculoskeletal disorders were significantly correlated with age and work experience (individual characteristics); responsibility, health concerns, and exercise (lifestyle); as well as physical workload and time pressure (mental workload) (P

Introduction: Work-related musculoskeletal disorders are among the most common diseases that cause absenteeism and disability. Exposure to ergonomic risk factors in construction workers increases the risk of discomfort and musculoskeletal disorders in this group. The present study investigates occupational and individual factors predicting musculoskeletal disorders and pain disabilities in construction workers. Material and Methods: The present cross-sectional study was conducted on 346 construction project workers in Tehran. To study the prevalence of musculoskeletal discomfort, job stress, and pain disabilities, Cornell Musculoskeletal Discomfort Questionnaire, Job Content, and Pain Disability questionnaires were used. Results: The results of the present study showed that the highest rates of musculoskeletal discomfort were in the neck (68%), left knee (64%), right knee (86%), and back (61%), respectively. The mean score of pain disability was 35.43 ± 20.18, and 16% of people were in severe disability. The results showed that with increasing work experience, working hours per day and body mass index of pain disability increases, and age, work experience, body mass index, and the component of physical needs of the job are the contributing factors of the musculoskeletal discomforts. Conclusion: Musculoskeletal disorders and pain disability were high in the studied construction workers. Based on the results, age, work experience, body mass index, and job stress contributed to musculoskeletal disorders and pain disabilities. Therefore, this study's results can help to understand better the risk factors affecting musculoskeletal disorders and pain disabilities in construction workers.

Background and Objective: One’s work ability depends on individual and occupational factors. Improving the work ability increases the person’s efficiency and job satisfaction. The present study aimed to evaluate the work ability and determine the relationship between neurotoxic symptoms and individual factors with the work ability of operating room nurses. Materials and Methods: The present cross-sectional study was conducted on 121 operating room nurses at a teaching hospital in Tehran in 2021. Data were collected using the demographic characteristics form, work ability index (WAI) questionnaire, and Euroquest questionnaire and analyzed using SPSS software (version 23). Results: Based on the results, the mean±SD WAI was obtained at 31.52±4.8 for the nurses. It was found that work ability had a statistically significant negative correlation with neurotoxic symptoms (r=-0.75; P

Introduction: Resilience is one of the competencies that enable nurses to adapt to stressful risk factors at work and demonstrate a healthy and stable psychological performance. The present study aimed to investigate the predictive role of resilience on job stress among Iranian nurses. Methods: The current cross-sectional study was conducted in Ahvaz, Iran, with participation of 200 nurses in May 2019. Participants were recruited via stratified random sampling. The resilience indicators and job stress data were collected by the Connor–Davidson Resilience Scale and OSIPOW Job Stress Questionnaire. Results: The results showed a significant negative correlation between resilience and job stress (r = −0.824, P < 0.05). Similarly, a significant linear regression existed between job stress and resilience (β = −0.824, P < 0.05) in such a way that resilience predicted 67.9% of the job stress variance in the participants (R2 = 0.679). In addition, it was revealed that the multi-aspect model could significantly predict job stress based on linear resilience indicators (P < 0.05). Conclusion: The results indicated that resilience indicators have a significant relationship with job stress, and this relationship can be used to predict changes in job stress based on resilience. Therefore, it is strongly recommended that resilience improvement programs should be developed and implemented for nurses.

Introduction: Heat stress is a critical problem in hot industries, especially in incredibly hot climates. It can greatly impair the work process and put the health of workers at risk. This study aims to investigate the applicability of the WBGT index in determining the allowable working time in very hot weather conditions in one of the steel industries in Ahvaz. Material and Methods: This study was conducted in different sectors of a steel industry in Ahwaz. The physiological parameters of sixty workers working in different parts of the industry were evaluated. Environmental variables and the Wet-Bulb globe temperature (WBGT) Index were also simultaneously measured during work shifts. The acceptable work time was calculated based on the reserve heart rate (RHR) and the WBGT index. Results: The heat stress index among all occupational groups, based on the WBGT index, was incredibly high and surpassed the recommended level (P

Introduction: Considering the accreditation of international standards of hospitals and the necessity to improve the safety and quality of patients’ care, this study aimed at evaluating reliability among nurses using predictive analysis of cognitive errors and human event analysis techniques. Material and Methods: The analysis of nurses̓ tasks was done by HTA method. Then, the types of errors and their causes were identified by TRACER method. In the next step, the error probability of each task was calculated by ATHEANA method. In order to calculate the probability of total event, the probability of human error was imported to probabilistic risk assessment. Results: Factors affecting performance of the nurses were included: the complexity of the work, high workload, nurse’s experience, work environment design, fatigue, anxiety, shortage of the workforce, insufficient time period for doing job, sleep disturbance, and poor lighting and noise pollution. According to the instruction of ATHEANA method, the error probability for each base event was considered 0.001. Given that there are 15 base events, the probability of human error in the heart attack event was calculated 0.015. Conclusion: The finding of this study was indicated the need for providing required nursing workforce, reducing overtime, scientific planning for nurses’ work shifts and giving practical training and stress management methods in the emergency conditions.

Background and aim: Physical work capacity is one of the significant issues in work physiology which is used to investigate compatibility between work and worker. Body composition is among the factors affecting maximal aerobic capacity. Accordingly, the present study aimed to examine the effect of anthropometric components and body composition on physical work capacity and to present a final model for estimating physical work capacity using direct and instrumental methods. Materials and Methods: A total of 50 male students were randomly selected in this cross-sectional study. The Bruce protocol and the h/p/cosmos-treadmill (Saturn model) were used to estimate the maximal aerobic capacity. Body composition was also measured using the Body Composition Analyzer Device (Olympia 3.3 model). The relationship between the variables was investigated using Pearson correlation coefficient and regression analysis. Finally, a model was presented to estimate maximum oxygen consumption based on linear regression analysis. Results: The mean maximal aerobic capacity (ml/kg/min) of students was estimated to be 44.01 ± 4.75. Also, the mean body mass index and body fat percentage of students were 24.03 ± 4.31 kg/m2 and 20.77 ± 7.6%, respectively. The mean waist-to-hip ratio was 0.803. The present study indicated that there was a significant and negative relationship between maximal aerobic capacity and body composition. Conclusion: A model is proposed in the present study since estimating the physical work capacity requires acceptable accuracy and valid relationships and equations. The variables of body mass index, body fat percentage, and waist-hip ratio which play an effective role in estimating physical work capacity and the maximum oxygen consumption can be estimated with high accuracy based on the presented model.

Background: The trans-theoretical model is a model that is very sensitive to changes in the minor progress of behavior. Therefore, the trans-theoretical model is more practical than other patterns of behavior change, which have been considered all or no to measure physical activity. This study aimed to standardize and determine the validity and reliability of the tensile movement questionnaire at the University of Medical Sciences employees. methods: In this study, after searching the texts and the study of the same questionnaires and tools and among the available and related tools, the initial questionnaire was designed. First, the validity and content of the questionnaire were measured using expertschr('39') comments. Then, the ability to understand the questionnaire based on the opinions of 10 employees was investigated. Finally, to determine the reliability with the experimental-open test method, 30 employees, Cronbachchr('39')s alpha, and the correlation coefficient were obtained using SPSS software. Results: After performing the necessary reforms with expertschr('39') opinions, finally, the questionnaire with increasing the number of questions of the field of self-efficacy from 6 to 7 questions, the reduction of the number of questions of the interests of stretching movements from 10 to 5 questions, increasing the number of questions of the barriers of stretching movements from 4 to 7 questions and increasing the number of questions of In the validation stage, each 40 of the questions had acceptable content validity (8.0 to 99.0). Also, at least 80% of the questions were diagnosed in terms of the target group acceptable. Cronbachchr('39')s alpha coefficient and correlation coefficient were 86.0 and 7.0, respectively. Conclusion: A designed questionnaire based on the trans-theoretical model constructs to assess educational intervention to enhance the tensile movements of employees has acceptable reliability and validity.

Background and aims: Back pain among construction workers has a high prevalence compared to other jobs. Based on qualitative studies, numerous risk factors are involved in the development of back pain. The present study was conducted to evaluate prevalence of musculoskeletal disorders and the compressions loads on back based on surface electromyography in construction workers. Methods: This study was conducted on 30 workers of various professions of building construction (rod busters, mason, stonemason, and manual material handling workers) in ahvaz city, Iran. In order to estimate the compression loads on the back, the surface electromyography technique was used, processing signals were determined using MATLAB software and analysis and interpretation of data were determined based on amplitude probability distribution function. The covariance analysis test was used to compare the compressive loads on the low back (L4/L5) as well as the exposure time between different occupational groups. Results: The highest and lowest mean of compression pressure (50th percentile) was estimated among the manual material handling workers and masons, respectively. There was a significant difference between the compressive loads on the back among different occupational groups(p

Background: In the face of COVID-19, healthcare workers need to cope with the ongoing stressors at play and keep psychological distress at a minimum level. This study examined the psychosocial and demographic factors associated with nurse's resilience in the hospitals of Ahvaz that is one of the top cities infected with COVID-19 in Iran.Methods: The present cross-sectional study was conducted on 387 Iranian nurses in Ahvaz city. For data collection purposes, three online questionnaires (including Copenhagen Psychosocial, Demographic, and Connor–Davidson Resilience Scale) were distributed among the participants.Results: The mean resilience score was equal to 61.8 ± 14.8 for 387 nurses. Resilience had a statistically significant negative correlation with quantitative demand (r = −0.273, P < 0.008), work pace (r = −0.262, P < 0.011), emotional demand (r = −0.226, P < 0.030), stress (r = −0.458, P < 0.000), and burnout (r = −0.287, P < 0.005). Multiple linear regression analysis indicated that stress, job satisfaction, burnout and age were the main predictors of nurses' resilience during the (COVID-19) pandemic (R2 = 0.45).Conclusions: We identified psychosocial and demographic predictive factors that may contribute to greater resilience among nurses during the COVID-19 outbreak. The findings of this study can be used to implement psychosocial interventions to amplify the resilience of medical staff during the COVID-19 outbreak.

Background and Objective: Job stress is one of the factors affecting workers' health and occupational productivity. In recent years, stress has been considered as a factor in the loss of productivity and efficiency induced by stress. This study aimed to investigate the effect of job stress on workers' productivity in one of the Oil and Gas Companies in Southwest Iran. Materials and Methods: In this study, two separate questionnaires, namely Health and Safety Executive and productivity questionnaire (by Saatchi) were used to assess the job stress and workers' productivity. The validity and reliability of these questionnaires have been reviewed in previous studies. The data were analyzed in SPSS software (version 24). Moreover, a P-value less than 0.05 was considered statistically significant. Results: According to the results, the mean score of workers' job stress was 3.68 ± 0.43. The results showed that 36.4% and 63.6% of the workers had low and no stress, respectively. In addition, there was a reverse correlation between productivity and job stress with dimensions, such as role, relationship, support of authorities and coworkers, as well as demands (P

The purpose of this study is to investigate the effect of resistance spot welding (RSW) parameters on nugget size and ultimate strength of Magnesium alloy sheets AZ61 under tensile-shear test. In this study microstructural examination and hardness measurements were carried out on the welded samples. The results show that the weld nugget zone is divided into two separate parts: the equiaxed dendritic zone (EDZ) perched at the center of the weld nugget and the columnar dendritic zone (CDZ) situated around the fine-grained zone having it surrounded. The effect of the following three parameters: electric current, welding time and electrode force on the dimensions of the weld nugget and the welded ultimate strength is investigated. The response surface method (RSM) is employed to examine the effects of welding parameters and to attain optimum parameters. The analysis of variance (ANOVA) results of RSM model shows that however the tensile-shear strength and nugget size are improved with increasing the welding current and welding time, the welding current is the most influential parameter. In addition, the optimal values for the welding parameters are calculated to achieve the maximum nugget size and the ultimate strength of welded joint. Finally, a regression model is proposed in order to predict the peak load and the nugget size as function of the mentioned welding parameters.

In industry and developed societies, annual work accidents can bring about huge losses. By proper analysis of these events, the development of controlling measures can be the most important action to prevent similar events and enhance the health of the society. Hence, the current study was aimed at analyzing a case of occupational accidents leading to death in one of the car industries. This qualitative case study was conducted in spring, 2018. With the implementation of Systems Theoretic Accident Model and Processes (STAMP), the incident statement had been described accurately and, then, a safety control structure has been designed to determine inadequate effective safety control actions in the event of an accident. In the analysis of the incident, various factors were involved at different levels of incident hierarchy where the various components of socio-technical systems interact with each other; the inadequate control action of the safety unit was more prominent. Based on the STAMP technique, unlike traditional methods, does not consider the cause of the accident just a component of failure or malfunction of the system. Therefore, it provides a useful tool in incident analysis, especially in complicated and sensitive systems.

Background and aims: Iranian lifting guidelines are used as a risk assessment tool to prevent back pain in various industries. It is believed that the tools and methods used for the assessment should be simple and yet accurate.Given that this guideline adopted the American Conference of Governmental Hygienists (ACGIH) threshold limit values (TLVs) for lifting as allowable load limits and the accuracy of the allowable weight values has not been investigated. The objective of this study was to investigate the effect of trunk angle and anthropometric dimensions on the accuracy of the allowable weight limits. Methods: In this study, 15 workers who had experience in manual handling were asked to perform lifting tasks in accordance with the Iranian guidelines. The subjects’ anthropometric and trunk inclination angles were recorded using a triaxial accelerometer (inclinometer) for each task, and the compressive forces were estimated using 3DSSPP and then compared with NIOSH’s recommended limits (3400N). Results:The results showed that among 25 tasks, the mean trunk angle of 13 tasks was between 90 and 130 degrees. Statistically, considering a standard deviation above the determined mean, the average compressive forces estimated for 9 tasks were greater than NIOSH recommendation (3400). Conclusion: In most tasks, vertical height and horizontal distance of external loads from the body leads to awkward postures that can be the main reasons for increased compressive force. Lack adaption some anthropometric measurements result in increased mechanical loads on the back. Therefore, it seems that the limit values for Iranian lifting guideline are not sufficiently accurate to assess the risk of back injuries and needs to be reviewed.

Background and Aim Musculoskeletal disorders are one of the most important occupational problems among healthcare personnel. Among them, nurses are known to be at the top of the range considering due to their physical and psychological needs. The purpose of this study was to compare the methods of risk assessment of manual transportation of patients in nursing staffs of Ahvaz University of Medical Sciences hospitals. Materials and Methods This cross-sectional study was conducted among 41 hospital nurses under the auspices of Jundishapur University of Medical Sciences in Ahvaz in spring of 2017. Scores of personnel for carrying patients were collected using MAPO checklist and PTAI and finally, data analysis was performed using SPSS19 software and Chi-square and Spearman tests. Results According to the results of our data 62.68% and 91.11% of the subjects were at risk of musculoskeletal disorder (the MAPO and PTAI index, respectively). Based on Pearson statistical test, there was no significant correlation between MAPO and PTAI findings in this study. Conclusion Given the differences in the nature of measurement tools, the scoring method of measuring items for the MAPO and PTAI risk assessment methods, both methods are very useful tools for determining and assessing the risk of manual transport of patients.

Introduction: Measurement of Maximum aerobic capacity (VO2-max) is important in physiologically fitting the workers to the job. The objective of this study was to investigate the effect of anthropometric and demographic factors on physical work capacity. Methods: Methods: In this study 60 students of Ahwaz University of Medical Sciences were selected voluntarily. A checklist consisted of two sections was used as data collecting tool. The first section included demographic characteristics. The second section included anthropometric characteristics of the students. Students aerobic capacity was assessed by ergometer according to Astrand protocol for 6 minutes. Linear regression analyses were performed to investigate association between demographic variables and VO2-max. Results: Students aerobic capacity was estimated to be 2.19 0.56 lit/min and 35.95 8.97 ml/kg. min. Statistical analysis revealed association between VO2-max with sex, weight, height, body fat percentage (p ≤0.01) and width of shoulders (p ≤0.04). Conclusion: Among the demographic factors showed that only sex and anthropometric dimensions weight, height, width of shoulders and body fat percentage were significantly associated with physical work capacity. Therefore, using the regression equations mentioned in this study, it is possible to estimate the physical work capacity according to the gender and anthropometrics dimensions.

Background: The present study aimed to evaluate the biomechanical exposure to the trapezius muscle activity in female weavers for a prolonged period in the workstation A (suggested by previous studies) and workstation B (proposed by the present study). Methods: Electromyography data were collected from nine females during four hours for each ergonomically designed workstation at the Ergonomics Laboratory, Hamadan, Iran. The design criteria for ergonomically designed workstations were: 1) weaving height (20 and 3 cm above elbow height for workstations A and B, respectively), and 2) seat type (10° and 0° forwardsloping seat for workstations A and B, respectively). Results: The amplitude probability distribution function (APDF) analysis showed that the left and right upper trapezius muscle activity was almost similar at each workstation. Trapezius muscle activity in the workstation A was significantly greater than workstations B (P

Background and aims : Musculoskeletal disorders are common among nursing personnel e pidemiological studies have demonstrated the highest prevalence of back pain among nursing assistants. The aim of this study was to continuously monitor lumbar sagittal and frontal postures of nursing assistants in a hospital of Khuzestan province. Methods : The study population consisted of sixty nursing assistants working in different departments of the hospital. Nordic musculoskeletal disorders questionnaire (NMQ) was used to determine the prevalence of low back pain of workers in 2012. A portable triaxial inclinometer electronic device was used for continuous monitoring of postures of back in nursing assistants. Sampling time was 2 hours determined with a frequency of 7.6 Hz. The percentage average of natural and extreme postures in different parts of the hospital were compared by table analysis of variance . The logistic regression was used to relate the survey of awkward and natural postures in relation to the back pain . Results: The results showed that the prevalence of low back pain among nursing assistants was 60 % in last year. The highest and lowest percentages of extreme postures in flexion / extension (over 20 °) obtained in the internal department (85.6 %) and female surgery department (13.1 %), respectively. The poor postures in the lateral bend (more than 20 °) obtained in the orthopaedic department (68.4 %) and male surgery department (7.9 %). Conclusion: The present study indicated that using electronic inclinometer is able to record continuous monitoring of trunk postures in sagittal and frontal planes. It could also be employed with high care without interfering with individual activities for assessing the risk of back injuries. Likewise, awkward postures can be a high risk factor for nursing assistants in causing low back pain while working , which requires for ergonomic interference to diminish physical workload.