جستجوی مقالات مرتبط با کلیدواژه « ergonomic risk factors » در نشریات گروه « پزشکی »

The risk of musculoskeletal disorders due to various work factors such as ergonomic factors in truck drivers is considerable. The aim of this study was to investigate the effect of ergonomic risk factors on the prevalence of musculoskeletal disorders in truck drivers.

This cross-sectional was a descriptive-analytical study that was performed on 200 professional truck drivers by two-stage cluster sampling. The ergonomics and safety of drivers’ questionnaire including demographic characteristics, working conditions (stress and job satisfaction), pain in nine areas of the body in the last 12 months based on body map were used. The central indicators and Spearman non-parametric statistical tests were used to analyze the data.

The mean (±standard deviation) age of drivers was 47.5±9years, who drove an average of 10.66 hours in 24 hours. 99.5% of drivers complained of low back pain, of which 40% were mild and 59.5% were severe. Also, 59.5% reported severe pain in the knee area. The relationship between pain in the elbow and foot with moving and carrying of loads as well as neck and wrist pain with hand and arm movements was significant (p<0005). No significant relationship was found between pain in nine areas of the body and job satisfaction.

Ergonomic risk factors play an important role in the occurrence of musculoskeletal pain in drivers, which requires special training and attention to this occupational group along with preventive and therapeutic measures.

Musculoskeletal disorders are one of the main problems of industries and administrative jobs, which are caused by various factors. The study aimed to determine the role of each individual, physical, psychosocial, and environmental factors in causing musculoskeletal disorders; Identifying and controlling risk factors, is an important step in reducing and preventing these disorders.

The present study is a cross-sectional study of 342 employees working in different government offices in Saveh city in 2021. In this study, the Nordic summary questionnaire and ROSA checklist were used to investigate the prevalence of musculoskeletal disorders. Also, to investigate individual and psychosocial factors of the work environment, a personal information questionnaire and a general Nordic questionnaire were used. In addition, the evaluation of conditions of work environment was done by Hagner model E1 lux meter devices, TIS10 model thermal stress measuring device, and TES1358 sound meter. Finally, all the resulting data were entered into SPSS software and tested after coding.

The results showed that body mass index and gender have a significant effect on suffering from musculoskeletal disorders (p-value<0.05). The results of the Pearson correlation test indicated that there is a significant relationship between the report of pain or discomfort in the neck area with the screen-phone risk score, wrist/hand with the keyboard-mouse risk score, as well as shoulder, upper back, elbow and lower back with the chair risk score. p-value <0.05). In addition, there is a significant relationship between the report of pain or discomfort in the neck, shoulder, and wrist/hand areas with the overall ROSA score. Also, there is a significant difference between the prevalence of musculoskeletal disorders and levels of job demands, levels of job control, levels of social interactions, levels of leadership, levels of the organizational atmosphere, levels of job satisfaction, and levels of stress (p-value<0.05).

The results of this study showed that several factors play a role in musculoskeletal disorders, such as job requirements, social interactions, and stress in the group of psychosocial factors that had considerable importance in causing musculoskeletal disorders. Among the individual factors, gender and body mass index (BMI) is important, and among the workstation factors, the chair has played a significant role in causing musculoskeletal disorders.

Prevalence of musculoskeletal disorders (MSDs) is high among office workers. One of the most important risk factors of these disorders is awkward posture and inappropriate environmental conditions. So, this study was carried out to determine frequency of MSDS and its related risk factors among the office workers of Minab city healthcare centers in 2018.

This cross-sectional study was conducted on 104 staff in Minab city health care centers. Nordic musculoskeletal disorders questionnaire was applied to determine the prevalence of MSDs and Rapid Office Strain Assessment (ROSA) method was used for posture analysis. The data were analyzed by SPSS version 21 using descriptive statistics and chi-square test. Excel software was used to plot the graph.

The highest prevalence rates of MSDs were reported in low back (63.5%), neck (51.9%) and upper back (50%). There was no significant difference between MSDs and age, sex and BMI (P˃0.05) but there was a significant relationship with work experience (P˂0.05). Totally, 36.6% of employees were placed in the first priority of corrective actions (i.e. the need for ergonomic interventions as soon as possible). There was a significant correlation between awkward posture and neck pain (P <0.05).

The frequency of MSDS in health center office workers was high and neck pain was related to awkward posture.

Musculoskeletal discomfort is one of the most important causes of occupational disabilities in many work communities which cause high costs for the economies of countries. Studies signifies the importance of implementation of programs to control these discomforts. In this regard, the ranking of occupational and work-related diseases provided by the World Health Organization (WHO) has shown that musculoskeletal disorders had second place after work-related respiratory diseases in 2013. Agricultural workers are at high risk of musculoskeletal disorders due to the nature of their intense physical activities and high level of manual labor. Indeed, farmers experience a variety of physical pressures due to repetitive lifting and carrying heavy loads, working with inappropriate tools, working in undesirable conditions with awkward postures (bended and/or deviated trunk, abducted arms, working at height higher than shoulders, etc). They usually work with vibrating tools and are exposed with other hazards such as falling or slipping. Many observational ergonomic assessment tools are designed for evaluating the postural risk of different job tasks. Some examples include the Rapid Upper Limb Assessment (RULA), Rapid Entire Body Assessment (REBA), Quick Exposure Checklist (QEC), and so on. Agriculture is an occupation that depends highly on working methods and equipments. As a result, workers can adopt different postures as a function of their tasks and situations. It is assumed that their working postures would be more or less different from industrial workers. The majority of previous researchers applied typical existed methods to evaluate farmer’s working postures, since there was no specialized evaluation method. This lack of a proper agricultural evaluation method has recently been resolved by Kong et al. (2015), who introduced a methodology entitled “Agricultural Whole-Body Assessment” (AWBA) for this purpose. This approach covers a wide variety of body postures which are especially existed in agricultural tasks. Agricultural workers and their ergonomic conditions are rarely investigated in Iran. To our knowledge, no study has yet paid attention to the working posture of Iranian agricultures using AWBA. Considering the high number of workers in this section, and the lack of required information in order to decide appropriate interventions, the present study is conducted to assess the prevalence of musculoskeletal discomfort and the evaluation of working postures among fruit picker in Iran. 

A total of 135 fruit picker working in Damavand apple gardens voluntarily participated in this study. The study was approved by the ethics committee of Shahid Beheshti University of Medical Sciences and the written consent form was signed by each participant before starting. The inclusion and exclusion criteria for the study were having at least one year of working experience in the fruit picking job, and lack of any specific work-related musculoskeletal disorders. Also, individuals who experienced acute musculoskeletal injuries due to non-occupational reasons during the study, and those who declined to continue their participation for any reason were excluded from the study. In this study, only fruit pickers who picked fruit from short trees without needing to ladder were entered. A researcher-made questionnaire was used to identify the demographic and occupational characteristics of the employees. Accordingly, factors including age, sex, height, weight, and work experience were collected. The prevalence of musculoskeletal discomfort was recorded by a body map questionnaire during the study period. The body map questionnaire attempts to identify body regions involved with musculoskeletal disorders. The body map questionnaire classifies whole human body into nine anatomical areas. Workers were asked to mark each area in which they feel discomfort. AWBA was used to evaluate working postures and to determine the ergonomic risk level. This tool provides the risk levels for the upper (AULA) and the lower (ALLA) limbs, taking into account the different postures of the body during the work as well as the working duration in each posture. Finally, using a 4x4 matrix, the overall risk level of the whole body is determined. The final risk levels can range from 1 (low) to 4 (extremely high).  Data was analyzed with SPSS software version 16, using t-test and Mann-Whitney test. 

The prevalence of musculoskeletal discomfort among the studied fruit pickers was 31.9%, 22.2%, 20.7% and 14.8% in lower back, knees, legs/foots and shoulders respectively. In total, 88 out of 135 workers (65.2%) experienced musculoskeletal discomfort in at least one region of ​​the body while 47 workers (34.8%) reported no discomfort. The age of participants ranged from 12 to 73 years (mean = 35.9 ± 15.7). The history of work ranged from 2 to 50 years with an average of 12.8 ± 11.4. Individual characteristics including age, height, weight, work experience and body mass index were not related with the presence of musculoskeletal discomfort among studied workers (P >0.05). According to the results obtained from the Agricultural Whole-Body Assessment method, the risk score of three was calculated for the upper limbs (AULA), lower limbs (ALLA) as well as whole body (AWBA); indicating high risk of musculoskeletal disorders in fruit pickers due to their excessive exposure to physical ergonomics hazards. 

Fruit pickers are at high risk of musculoskeletal disorders. Awkward working postures in manual fruit harvesting may be considered as the main cause for the incidence of MSDs in this working group. Although the lower limbs (foot, legs, knees) of fruit pickers seem more painful than other body parts, it is important to consider their whole body (including lower and upper limbs) in the case of designing any ergonomic improvements, since both lower and upper limbs are at high risk of MSDs in traditional apple harvesting. Therefore, appropriate yet prompt ergonomic interventions should be implemented. In this regard, moving to the mechanized agriculture seems to have the highest priority among all possible interventions. However, until it could be realized, other ergonomic improvements should be adopted. These include all changes resulting in reducing repetitive movements, modifying working postures (i.e. avoiding excessive bending, twisting, deviating, abducting arms, working over the shoulder height, reaching beyond the natural working zone envelope, etc), decreasing prolonged standing, and reducing exposure to the biomechanical risk factors such as force and prolonged working hours. It is also recommended to improve the traditional methods of fruit handling and carrying by designing ergonomic baskets dedicated for this purpose.

Upper limb musculoskeletal disorders are prevalent and undesirable health consequences among workers in clothing industry. To improve working conditions, workplace ergonomic assessment is necessary. This study was conducted among workers of clothing manufacturing workshops to determine the prevalence of musculoskeletal disorders and to assess ergonomic working conditions to identify major risk factors associated with musculoskeletal symptoms.

One hundred and fifty female workers from clothing manufacturing workshops of Yazd city participated. The Nordic questionnaire and an ergonomics checklist consisting of 6 sections were used as data collection tools. An index was calculated for each section of the checklist. Action categories indicating the priority of corrective measures were also defined. Data analysis was performed using the ANOVA and ROC curve tests by SPSS software (version 17).

The results showed a high prevalence of musculoskeletal disorders, especially in the upper limbs among the study population. In this study, a significant association was found between the calculated ergonomics index and MSDs in different body regions (p<0.05). The mean of this index among the workers who reported symptoms was less than those of the other group indicating undesirable ergonomic conditions. In addition, 68.7% of the workers were categorized in the first priority of intervention (requiring ergonomic intervention as soon as possible).

The prevalence of MSDs was high among the workers of clothing workshops. The developed checklist was considered as an appropriate and low cost tool for ergonomic evaluation of sewing workshops. The results also indicated that most ergonomic problems in these workshops originate from inappropriate general working conditions, work organization, manual material handling, hand tools, workstation and working post

Exposure limit of employees with ergonomic risk factors should be managed based on domestic and international laws and regulations. Manual tasks are tasks due to which a person is required to use part of the body to lift, lower, push, pull, carry and hold the material. The purpose of this study was to introduce ergonomics with the implementation of the PErforM Participatory ergonomics program.

The present study was carried out on all employees working in the Reactor Charging Unit of a resin company during the year 2017. The participatory ergonomics for manual tasks (PErforM) Method was used to manage ergonomic risks due to manual tasks. After holding several training sessions, ergonomic risks have been identified and evaluated using the ManTRA (Manual Tasks Risk Assessment) tool and also by staff. Then interventions suggested by the staff using the DotMocracy tool were eventually implemented. Also, the proposed interventions were simulated before implementation, in order to assess interventions’ implementation.

The tasks of pushing pallets containing 800 kg bags and machines with 25 kg bags were identified as risky manual tasks using ManTRA. After the interventions using participatory ergonomics, the intensity of repetitive tasks and force in the areas of the hands, shoulders and lower back were reduced.

Generally, the PErforM has a high capacity to modify employee’s exposure to ergonomic risk factors, as well as to discover effective, simple, and effective control strategies. However, achieving this goal requires the promotion of ergonomic knowledge and management commitment.

Ergonomic trainings does not cost much in comparison to other interventions, such as changing work procedures, using new technologies and also redesigning workstations. The aim of this study was to investigate effect of continuous ergonomic training on productivity and exposure to ergonomic risk factors.

 In this study, 51 employees of one of Tehran's food industry in year 2018 were selected by random sampling method. Demographic and productivity data respectively were collected by Demographic and Achieve questionnaires. The exposure to ergonomic risk factors evaluated by Quick Exposure Check (QEC) method. This information was re-collected after a four-month ergonomic audio-visual training course. Then, by using the paired t-test, the effectiveness of this training course was evaluated.

Data indicated that almost half of the workers were in the worst possible posture; The number of people in this group did not change before and after the training, also two thirds of the samples had a moderate productivity score that training couldn’t change number of this group too. However, despite the lack of significant changes in the categories of exposure to risk factors of ergonomics and productivity, the changes in scores within these two groups were significant. It means that this was not significant in the way that the levels of these two variables in the studied samples Change.

This study has shown that continuous ergonomic training could reduce the QEC score and also could be a reason for increasing productivity in the workplace.

 Lack of awareness of the principles and rules of ergonomics, inappropriate postures and frequent displacement of patients and loads Can cause musculoskeletal disorders in medical personnel. The purpose of this study is to evaluate the effectiveness of in-person training and social network education on the ergonomic risk factors and musculoskeletal of patient carrier personnel in the  Shahid Bahonar hospital of kerman.

The study has been done on 60 participants in Shahid Bahonar hospital. The participants were randomly divided into two groups of 30. The first group were trained via in-person training method combined with practical work and questionings and the second group were trained via social networks and data were collected through a questionnaire demographic, the questionnaire made their assessment  awareness, Nordic questionnaire along with the scale of the investment rate and the numerical checklist PTAI before Training for one week, one month and six months periods after training and SPSS software was used to analyse the collected data.

low back pain is more prevalent among the patient-carrier personnel. With a significant level of 0.05 in the Wilcoxon test. The amount of P-value at the end of the six-month period in the amount of awareness and  PTAI training approaching scores in both methods was less than 0.05 at a significant correlation. And the amount of P-Value in the analysis of musculoskeletal complaints in the six-month period, conventional training methods in the neck, shoulder, lower back complaint, knees and feet, is less than 0.05 and has significant relationship.Social network education did not result in any significant relationship at the end of six months.

According to the results based on exams ,in-person trainings or social network-based trainings both result in reduction of ergonomic risk factors , musculoskeletal complaints and muscular impact. The in-person education method was more effective rather than social network-based trainings.additionaly reliability of education’s effectiveness was meaningful only at the in-person education method.

The design and manufacturing process in electronic companies is the most time consuming work with the computer. Because of the high prevalence of musculoskeletal disorders in computer users, researchers need to identify risk factors and ergonomic problems and ways to reduce them.
This study was a descriptive-analytical study and was conducted as an intervention in Behpajooh engineering company in Isfahan. Statistical sampling was done by global sampling (31 people). The Nordic questionnaire and the Rapid Office Strain Assessment (ROSA) were used to evaluate the risk factors of ergonomics. Data analysis was performed by using McNemar and Wilcoxon's non-parametric tests and using SPSS software.
The results of the Nordic questionnaire; before ergonomic intervention, the frequency of problems in the elbow region is zero in the waist, upper back, neck and shoulders with a frequency of 45-38%. Evaluation of Ergonomic Risk Factors derived from the Rapid Office Strain Assessment before intervention showed that 35.5% (11 people) at low risk, 38.7% (12 people) in the warning zone and 25.8% (8 people) in the area requiring ergonomic intervention. Statistical analysis of ergonomic interventions shows that the number of people in the area of ​​warning and necessity is less than the number of people before intervention.
The most musculoskeletal disorders were reported in the neck, lower back, upper back and shoulders. Statistical results after ergonomic intervention indicate a decrease in these disorders. The results led to the understanding that the risks in electronic companies could be reduced by ergonomic interventions. Implementation of ergonomic interventions based on engineering, management and educational proceeding can be effective in reducing musculoskeletal disorders.

Manual material handling activities in long and short periods may lead to complications such as laceration, fracture, cardiovascular stress, muscle fatigue, and musculoskeletal disorders especially in the vertebrae column. The purpose of this study was to assess ergonomic risk factors in workers of a stone cutting industry and the impact of ergonomic interventions on reducing these risk factors in their workplaces.
Material and In a pre and post interventional study, identifying ergonomic risk factors of 50 male workers was done using WISHA checklist. Ergonomic interventions were implemented was: installation of a crankcase of the manorial vacuum and clamping crank, using a pallet with a portable two-way portable lift truck, a pallet for collecting waste with a roof crane or forklift truck, and a wagon lifting device. Statistical analyses were done using SPSS 20 and statistical tests of variance and Wilcoxon analysis.
Based on the results of the study, 78% of the workers had ergonomic risk factors at least in one of the 7 awkward postures at the beginning of the study, The most frequent risk factors were related to workers in stone loading, collecting stone waste (100%), middle part (76.2%), cutting-off (71.4%) and sub stations (50%). These values ​​were eliminated after ergonomic interventions in the loading workshop, sub, accumulation of stone waste (100%), and in the middle and cut-off workstations (42.8%). There was a significant difference between ergonomic risk factors before and after interventions (p The results of this study indicate that the prevalence of work-related ergonomic risk factors of workers in this industry was very high, but after the interventions, ergonomic risk factors decreased from 42.8% to 100%.

Present study aimed to determine rate of symptoms of the musculoskeletal disorders in different body regions and ergonomic assessment of the workplace and their risk factors among faculty members and other staffs.
This cross-sectional study was conducted on all 59 teachers and employees in School of Public Health, Qazvin University of Medical Sciences. Nordic questionnaire was used to determine prevalence of musculoskeletal disorders in various organs of the body. To assess workplace risk factors standard and integrated check list of office conditions was used.
Within the last year the highest prevalence of skeletal disorders was observed in hip (85.7 %) and neck & shoulders (64.3%) among academic members and back (60%) and wrist & neck (44%) among other staffs. Statistically significant associations were found between the prevalence of musculoskeletal disorders in neck and work experience among staffs and between the back disorders and working hour per day (p The prevalence of musculoskeletal disorders is high in hip regions of faculty members and lumbar region of other employees. Therefore, implementation of workplace ergonomics intervention seems necessary. Designing workstations according to ergonomic principles, training of teachers and employees on principles of ergonomics, job diversity, and soft exercise at certain intervals can be components of these programs.

TOPSIS as a method in Multi criteria decision making (MCDM) helps decision maker(s) to organize and analyze problems, and to rank alternatives. In this paper, the ergonomic risks factors which may influence health are addressed in a manufacturing company in 2014. Then TOPSIS method is applied to select the different halls that are prioritized in terms of action level and ergonomic conditions.
This cross-sectional study was done as a descriptive-analytic procedure. It considers conditions in seven halls and 13 tasks were included. Required Information gathered by the demographic questionnaire and ART method for repetitive task assessment. Also TOPSIS as a suitable multi criteria decision making instrument was used to prioritization of company halls. SPSS V20 and MATLAB are used to compute the variables.
The total exposure score based on the ART method equals to 30.07±12.43 were calculated. Data analysis from ART illustrated that 179 cases (74.6% of tasks) were in the high level of risk area and 13.8% were in the medium level of risk. ART-TOPSIS results revealed that Leher hall has been placed in the top lists of action level and degradation hall in the end of this list.
obtained results showed that the TOPSIS method can be used to ergonomic and human factor engineering challenges successfully. It seems that, macro and micro ergonomic solution presentation besides employee's collaboration, based on the scientific decision-making procedures (with employer's cooperation motivation), can leads to effectiveness in health level enhancement of industrial setting increasingly.

One of the most common causes of occupational injuries in industrialized and developing countries is musculoskeletal disorders Determining the risk factors of musculoskeletal disorders can be helpful choosing the right method for interventions and detailed studies. This study aimed to evaluate the ergonomic risk factors in operators of pressurized irrigation equipment factory.
This cross-sectional study was conducted in a pressurized irrigation equipment manufacturing company. In this study, a new method based on observation was used to evaluate the ergonomic aspects of operator's activity. In order to assign tasks and sub-tasks, direct observation and video recording equipment were used. Ergonomic assessment was carried out on all sub-tasks identified. then, the criticality of the task determined.
Among the tasks identified 53 very critical posture 61 critical and 82 low critical posture was determined. Ergonomic point in the ball valve production line was 0.6 and 0.68 respectively for tow operator. For drop valve and automatic valve production line's ergonomic point was 0.52 and 0.67 respectively.
According to the results, posture analysis method used in this study is easy and accurate. The advantage of this method is 14 ergonomic domaines that covered whole body and time fragment of each task. Findings of previous studies showed good correlation between results from this method and OCRA method.
In this study, The most critical posture was related to operator's wrist, so it is recommended that control measures on wrist posture correction should be considered.

Musculoskeletal disorders are major concerns of the modern world due to their effect on the physical health and productivity of the workforce. More extensive research is therefore required to identify and prevent these injuries and control the risk factors causing their development. The present study uses a theoretical model of ergonomic interventions to examine and improve ergonomic conditions in an automobile spare part manufacturing plant. A total of 44 employees were selected through simple random sampling and according to the Morgan table from the 50 personnel working at the plant. The Nordic Musculoskeletal questionnaire and the review of ergonomics tips inventory were used to identify the ergonomic risk factors. Based on the theoretical model used in the research, the ergonomic intervention was performed in two stages. In the macro stage of the ergonomic intervention, 7 goals were set and 13 ergonomic recommendations were made in the form of several workshops and task forces. In the micro stage of the ergonomic intervention, 20 ergonomic risk factors were identified and 13 strategies and plans were suggested. With the senior manager's approval, 11 strategies entered the implementation stage with the aim of improving ergonomic conditions and increasing productivity at the workplace. The main outcome of the comprehensive ergonomic interventions performed in the present study was a modified organizational culture, entailing both direct and indirect benefits, such as providing low-cost or no-cost solutions to the problems, creating an active environment of continuous improvement, increasing employee's motivation for participation and being innovative in solving the problems, increasing the inclination among the employees to be an innovative thinker, improving communication between the authorities and the personnel and increasing the employee's general knowledge and capabilities.

Musculoskeletal disorders (MSDs) are the most important causes of workers disabilities، increasing compensations and reducing productivity in developed and developing countries. According bureau of labor statistics in 2010، 29 percent of injuries and musculoskeletal disorders are diseases that cause absence from work. The objective of this study is determining the role of response efficacy as one of the component of protection motivation theory to reduce ergonomic risk factors in one of manufacturing industries. In this cross-sectional analytical study 158 workers of an assembly industry were studied. In order to assess the ergonomic work stations. Quick Exposure Check method was used. The data gathered via exclusive interviews with selected workers using the questionnaire designed based on protection motivation theory and were analyzed. Content Validity Index and Content Validity Ratio values were calculated for validity and reliability was obtained by using Cronbach''s alpha coefficient. Results of the assessment to the QEC method showed that 37. 97% and36. 71% respectively of those at moderate and high risk groups. Also there was a significant negative correlation between response efficacy and QEC scores and action level Regarding negative significant correlation between self efficacy and QEC scores and action levels، designing educational program based on Protection Motivation Theory to decrease ergonomic risk factors is recommended.

Work-related musculoskeletal disorders (WMSDs) are the most prevalence problems of working populations in many developing countries and specifically in Iran. One of the most important disorders is Carpal Tunnel Syndrome (CTS) which has been reported in many industries, especially in workers of automotive companies. The aim of this study is the risk assessment of related factors of hand activity and combined effect of risk factors in occurring upper extremity musculoskeletal disorders (UEMSDs). In order to evaluate risk assessment the threshold of hand activity level technique (HAL_TLV) is used.

The sectional descriptive-analytical method was used in this study. In this method 44 workman in the impulse and hydraulic press salons of automotive company was selected randomly, in addition sampling was carried out by censuses report. Data was collected through checklists of hand activity level (HAL) and normalized peak force (NPF) and also site observation. The results of combination of these variables were put in HAL_TLV graph, in order to evaluate the risk level of mentioned tasks. Data analyzing was done using SPSS18.

The Results shows that 31.25% (5 workman) was at risk level A (low risk) and 73.3% (11 workman) was at risk level B (moderate risk) in the impulse press salon and in the hydraulic press salon 3.57%(1 workman) and 96.4% (27 workman) of each group was at risk level A (low risk) and risk level C (high risk), respectively. The analysis of results indicates that there are reverse significant relationship between HAL and NPF in the salon of impulse press (p<0.014,r=0.881). Moreover the same result was obtained for two workman groups of the hydraulic press salon, as r=0.881, p<0.001 for group 1 and r=0.68, p<0.004 for group 2.

The ergonomic risk assessment of hydraulic and impulse press salons shows hydraulic press compare to impulse press has the highest risk as level C (high risk) which may caused by excessive force with rapid and repetitive movements at this salon. Therefore it can be said, in occupations that workers must have set excessive force, the risk of upper extremity musculoskeletal disorders (UEMSDs) especially CTS may decrease via reducing the speed and repetition of movements. Finally the interaction between force, time and movement repetition may prevent musculoskeletal disorders.

Work-related musculoskeletal disorders (WMSDS) is one of the most important problems in working populations of Iranian industries; so, in order to evaluate the integrated roles and effects of various ergonomic risk factors inducing such disorders, the Strain Index (SI) methods was used. This was a cross-sectional study conducted on 448 male subjects including 63 controls working in administrative jobs and 385 cases working in lathing, welding, melting and foundry jobs using integrated procedure which includes observations, interview, Nordic Musculoskeletal Questionnaire (NMQ) methods and SI model. All workers were questioned. Data were analyzed using SPSS software v. 11 and Excel package. The most prevalent MSDs in upper limbs were found in melting lathing, foundry and welding respectively. There was a significant relationship between age and job groups (c =7.33; df=16; p<0.001). One-way analysis of variance showed a significant differences among means of calculated Strain Indices of administrative (1.06), lathing (6.52), welding (3.68), melting 7.79) and foundry (6.33) jobs (F=5.92; df=16; p=0.005). Also it was revealed that melting job was attributed as "hazardous job" (4 risk level), lathing and foundry jobs were referred to "moderate risk level" (3 risk level), welding job was allocated as "uncertain risk level" (2 risk level), and administrative job was attributed as "safe risk level" (1 risk level). Moreover, there was a significant relationship between DUE and job groups (c2=11.92; df=12; p=0.004).The paired ttest showed significant difference with direct and relatively complete correlation between means of Strain Indices in right (6.53) and left (4.29) hands (r=0.69; t=3.15; p<0.001). The Strain Index (SI) model can be referred as an efficient and applicable method for the assessment of ergonomics risk factors inducing upper extremity musculoskeletal disorders (UEMSDs), classifying jobs, correcting and modifying work situations and preventing DUE musculoskeletal disorders.