مجله ارگونومی
سال پنجم شماره 4 (زمستان 1396)

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.

Inadequate lighting in the workplace can cause unconventional changes in the posture of office workers. Poor ergonomic conditions in the office cause inappropriate postures during work and increase pressure on the musculoskeletal system which can cause some disorders in long-term. In this study, the relationship between work environment lighting with the prevalence and severity of musculoskeletal pain among office workers has been investigated.
In this study, the intensity of local illumination at work surface and at the perpendicular surface (perpendicular surface to the work surface and at the height if workers eye), and intensity of general lighting was measured based on the standard of The Illuminating Engineering Society (IES) using the SEKONIC, C-7000 SpectroMaster. Also, to assess the prevalence and severity of pain of musculoskeletal disorders, a Nordic Questionnaire, Body map index were used respectively. To assess the office work strain, Rapid Office Strain Assessment techniques (ROSA) were used. Data were analyzed by SPSS software version 21.
The results showed that the average intensity of general lighting, local lighting at work surface and at the perpendicular surface was 30.6%, 33.9%, and 38.4% lower than required illumination intensity of Occupational Exposure Limits (OEL). The neck and waist had the highest prevalence of the musculoskeletal disorder among the workers. The highest frequency percentage of scores in the ROSA method related to scores 5 (41.7%) which had a significant correlation with illumination intensity.
illumination intensity can be considered as one of the important factors affecting posture in administrative staff. Therefore, the improvement of illumination intensity can decrease the severity of musculoskeletal pain and improve the body postures of the staff and, consequently, increase their comfort.

Many workers, especially welders, have awkward postures during their working hours. Evaluating such kind of postures is done with the aim of corrective actions. Therefore, the present study was conducted to evaluate the activity of welder's muscles in common welding postures in gas transmission pipelines.
This cross-sectional descriptive-analytical study was performed on 15 welders of the Iranian Gas Transmission Co. After the required analysis, three postures that were most used in the gas transmission pipelines were identified to evaluate muscle activity. The electromyography (EMG) activity of the erector spinae, biceps femoris, vastus medialis, gastrocnemius medialis, gastrocnemius lateralis, tibialis anterior, rectus abdominis, abdominal internal oblique, abdominal external oblique, and semitendinosus muscles are evaluated in three postures. They are analyzed based on the maximum voluntary contraction (MVC).
The results indicated that the mean of muscle activity in the kneeling posture is significantly lower than two other postures (P The muscle activity of the welders in the evaluated postures was very high. Based on the findings of this study, the muscle activity was strongly affected by the type of posture and angle of the joints, So that the muscles activity in the kneeling posture was lower than the two other postures due to the suitable angle of joints and the direct transmission of body weight.

Participatory ergonomics means the active participation of all components of an organization in the development and implementation of ergonomic knowledge in order to improve the working environment, quality, productivity and safety of the organization. The purpose of this study was to investigate the appropriate process design with the participatory ergonomic approach and its impact on one of the printing industries.
This is an interventional study carried out in one of the printing industries. To identify the ergonomic risk factors of the Nordic Questionnaire and Ergonomic Review Points, and to evaluate the quality of work life in the NIOSH. The results were analyzed using SPSS20 software and paired t-test.
The scores of health, and working conditions from the supplementary review list were significantly increased before and after the implementation of the review points with participatory ergonomic approach. Analysis of the findings showed a significant improvement in quality of working life and reduction of musculoskeletal disorders after intervention (p According to the results, ­it can be concluded that the social skills and abilities of individuals have increased with participation in the participatory ergonomics process. Increasing the quality of worker's life has a significant role in improving the health of workers and reducing occupational accidents. Therefore, the implementation of participatory ergonomic program with the help of industrial managers can be an effective step towards achieving human health satisfaction and health.

Recently adaptive neuro-fuzzy inference system was used for physical work rate classification based on three parameters including %HRmax, HRrest, and body weight. The aim of this study was optimization of the mentioned model for a high accurate classification of physical work rate.
The heart rate and oxygen consumption of 30 healthy men were measured during a step test in the laboratory. The VO2max of the participants was measured directly during a maximal treadmill test. A relationship was presented between the calculated %VO2max as the gold standard of physical workload and the model inputs using ANFIS in MATLAB version 8.0.0. The genetic algorithm was coded and applied to the developed model as an optimization Technique.
accuracy, sensitivity, and specificity of the model were increased after optimization. The mean accuracy of the model was increased from 92.95% to 97.92%. The RMSE of the model was decreased from 5.4186 to 3.1882. Also, the maximum error of the mode in %VO2max estimation was ±5% after optimization.
The results of this study show that applying Genetic algorithm during training process can increase the accuracy and decrease the error of ANFIS model in the estimation of %VO2max. The presented model is a high accurate and simple implementation method for physical work rate classification. Also considering inter-individual differences is another advantage of this model.

The purpose of this study was to identify and prioritize some factors affecting the trainer's satisfaction of Technical and Vocational Training Organization (TVTO) by integrating QFD and Kano models.
In this study, 435 trainees, aged 18 to 22 years old, were selected to complete the Kano questionnaire through direct communication and interview with the user in one of the centers of technical and vocational education in Tehran, Iran. In this study, Kano model and quality function development (QFD) integration methods were used to improve the design of technical and vocational institution's workshops ergonomically and based on the needs of users. After completing the Kano questionnaire by these individuals, the responses were analyzed and the results were entered into the house of quality (HOQ) matrix.
The results of the house of quality (HOQ) matrix in this study showed that design and safe application factor, as one of the most important safety features, had a weight coefficient of j=7.35. However, the furniture adjusting criterion with a weight coefficient of j= 1.09 had the lowest importance from the user's viewpoint. In addition, the thickness of materials and furniture with an absolute significance of AI=52.1 had no significant relation with ergonomics and comfort.
This results showed that both the Kano model and QFD integration method can be used in identifying and determining the priorities of the product design and work environment from the user's perspective.

The workstation has main effect on the musculoskeletal disorders, so pay attention to the workastation of the staff is necessary. The aim of this study was to investigate the effect of workstation on musculoskeletal disorders in administrative staff.
30 administrative staff participated in this descriptive-analytical study. Data were collected by means of Nordic Musculoskeletal Disorders Questionnaire (NMQ) for The intervention was ergonomic design of three workstation( sitting, standing and sitting-standing) before and after of Intervention. In order to analyze the data, Student’s t-test and multiple regression analysis were used.
The mean )SD( of age and work experience of 30 employees were 44.3(5) and 20(5) years, respectively. There was a significant correlation (P=0.02) between type of workstation before and after the intervention, with the expression of musculoskeletal disorders. Also, there was a significant relationship between variables of musculoskeletal disorders in shoulders, necks, waist and hands with workstations. However, there was significant relationship between age, work experience and Bmi index with musculoskeletal disorders.
According to the results of this study the best workstation is a sitting-standing situation. Thus, by varying the type of workstations, musculoskeletal discomfort of employees will be reduced appropriately.

Problems and complications due to the unfavorable aspects of children's tables and chairs deformation of one of the issues of concern in the world.The aim of this study was to evaluate the changes in anthropometric dimensions of Mazandaran province between 1992 and 2014 is the primary school children.
These cross-sectional studies between 1992 and 2014, anthropometric data in two primary school students aged 6 to11 years of collecting secondary and minor creature of students, 254,204 people in 1992,the number of 1758 people and in 2014 the community students 208,820 people,the number 2336 samples were selected using stratified random sampling method by anthropometric measurements mechanical in 1992 and in year 2014 measured using anthropometric chair, camera and software Photographical anthropometric was made by researchers.The parameters of weight,height, sitting height,sitting shoulder height, width wide shoulders ,wide hips, thick thighs, buttock popliteal length,sitting, sitting knee and hip measurements were considered. Data analyzed by SPSS software version 20.
Comparison of the two study revealed that male students from 25.82 ±5.9 to 32.96± 11.5 kg(7.14 kg increase) and girls25.19± 6.5 to 32.84± 10.1 kg (7.65 kg increase), and height of boys from 127.26±9.6 of 135.7±8.4cm (8.4 cm increase) and during their height of 126.5±10.1 to 132.8±11.2centimeter(6.3cm increase) increased. In other anthropometric factors have also changed.
The results showed the changes in the size of anthropometric students over 22 years, and the need for precision in design and manufacture of equipment related to children, especially tables and chairs used in schools.