Iranian Journal of Ergonomics

Background and Objectives: These days, due to increasing of old people’s population, elderly is a world widely issue. According to World Health Organization (WHO) people older than 60 years old are called elderly. Becoming old leads to decline in physical ability and increase in physical limitations and therefore there is a need for matching the environment with elderly users. The aim of this study is to develop and valid of check lists for screening the environment risk factor and assessing of elderly functional ability for environment and tools designing.  
Methods: Present study is an analytical and descriptive study, which was performed in 20 houses for old people in Lar city. Data collection was done on existing articles and checklists, and also interview and observation with elderly. Existing checklist was evaluated in validity and reliability with high acceptable level.  
Results: Based on findings of this study, height of mirror of wash-stand, height of wash-stand, dimension of yard and doorway was considered in ergonomics risk factors checklist. Items like opening door personally was involved in Functional Ability checklist. Validity score was lower than 0.78. 
Conclusion: According to findings, it’s necessary to consider elderly limitations and ability in designing environment and tools in order to resolve their problems and increase their quality of life.

Background and Objectives: Studies have shown the effect of smoking on mental and cognitive performance of the individuals who need to concentrate on their work. The present study aimed to investigate the effect of smoking on cognitive performance of the automotive industry workers. 
Methods: In this case-control study conducted in 2018, 280 automotive industry workers were selected through the simple random sampling and then assigned to  two groups of smokers (100 cases) and non-smokers (180 controls). All the subjects were selected from the environments with the sound levels of 82 to 88 dB. The workers’ cognitive performance was also tested using the CPT, Stroop and Tower of London tests.
Results: The mean age of the case group was 36/02 (3/7) and that of the control group was 36/25 (3/65) years. The results showed that the scores of the TOL test in the case group (smokers) were lower than those of the non-smokers (OR=0/903, P<0.01), and other items of the TOL test had no significant relationship with the individuals’ smoking status (P>0/05). The Stroop and continuous performance tests also had a significant relationship with the individuals’ smoking status in terms of the number of correct responses and the response time as well as interference (P<0.01). Other items had no relationship with the individuals’ smoking status (P>0/05).
Conclusion: The results of this study showed that the use of cigarettes and nicotine substances significantly decreased the workers’ mental and intellectual performance, and smokers were more likely to suffer from concentration interference, low brain processing speed in decision-making, and low precision at work, compared to non-smokers.
 

Background and Objectives: Noise pollution is one of the most harmful physical factors in working environments in developed and developing countries, which has significant impacts on the workers’ quality of life. The aim of this study was to investigate mental and physiological effects of chronic exposure to noise.
Methods: This is a cross-sectional study carried out randomly in 2018 on 250 workers in the automotive Industry. To measure the subjects’ aggression and annoyance levels, the Buss and Perry’s Aggression Questionnaire was used as well as an annoyance questionnaire. In this study, blood pressure measurement was also done using ALPK2 mercuric pressure gauge.
Results: The results showed that there was a significant difference in the systolic and diastolic blood pressure and noise annoyance in the groups with a lower-than-85 and higher-than-85 dB sound pressure levels (P<0.001). Besides, the results of multivariate regression showed that the annoyance level and sound pressure level had a significant relationship with the workers’ blood pressure (P<0.01). Also, there was a significant correlation between aggression components and sound pressure level (P<0.01).
Conclusion: The results of this study clearly showed that chronic exposure to noise in work environments was associated with psychological and physiological changes, such as increased blood pressure and aggression levels. Hence, implementation of preventive programs can help reduce the incidence of the psychological and physiological disorders.
 

Background and Objectives: 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.
Methods: 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.
Results: 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.
Conclusion: 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.

Background and Objectives: One of the most effective methods for managing ergonomic risk factors in the workplace is to involve employees in identifying and assessing ergonomic risk factors and ultimately designing and implementing interventions by themselves. Therefore, this study aimed to implement a participatory ergonomic program, focusing on the transfer of ergonomic knowledge to employees, and to examine the effects of interventions on the macroeconomic indexes.  
Methods: This semi-experimental interventional study was carried out in cooperation with all staff of one of the medical diagnostic laboratories in Isfahan (11 people) in 2017. A participatory ergonomic program was implemented based on the Occupational Health Clinics for Ontario Workers Inc. (OHCOW) Guide. Then, the differences in the level of macro ergonomic elements such as job satisfaction and increase in motivating potential score of employees were studied before and after the interventions resulting from participatory ergonomic program (OHCOW) in this work environment. The data was analyzed using SPSS 23.
Results: Job satisfaction before and after ergonomic interventions had no significant difference (a relative increase), but in one of the scales, namely organizational climate, there was a significant change (P=0.016). Also, the motivating potential score of employees after the intervention was significantly higher than before (P=0.013).
Conclusion: In this study, participatory ergonomics were used to improve some aspects of macro ergonomic elements. Based on the results of this study, participatory ergonomics can increase some job satisfaction scores and motivating potential score of employees. Finally, it is suggested that allocate a longer duration for intervention utilization.

Background and Objectives: In recent years, due to the rapid growth of metropolitan cities and the shortage of urban public transport means, including urban bus transportation, many people are forced to travel in a standing position when using these vehicles. This situation may cause pain and discomfort and non-collision injuries for passengers. The purpose of this study was ergonomic assessment of the sit-standing seat in passengers standing on urban buses.
Methods: To do this study, 8 young people with a mean age of 25.25±2.12 years were enrolled. For evaluation and assessing the effect of sit-standing seat two methods of surface Electromyography (sEMG) and Borg scale scores were applied in Fall 2018. The data was analyzed using SPSS 24.
Results: In all body parts, except for the hip, the mean scoring of Borg’s scale for perceived discomfort in sit-standing position was less than standing position. Also, the amount of contractile activity of the leg muscles in sit-standing position was significantly lower than the standing position (P<0.05).
Conclusion: Considering the results obtained from the Borg scale scores and the contraction activity of the leg muscles as a result of the use of the mentioned seat, which led to a reduction in the level of discomfort and the leg muscles contraction, it is recommended to apply the sit-stand seat instead of being in a standing position.

Background and Objectives: The statics and actions of people during daily activities plays a major role in the physical and mental health and dynamics of the community. Given that humans deal with different things in a day, it is necessary that they are adapted to his features of body. The main goal of this study is to design and construct tables and ergonomic chairs for cartography, in accordance with the physical dimensions of students.
Methods: In this research, one of the most used educational furniture, namely cartographic table and chairs, has been studied. After examining the satisfaction of this furniture, for ergonomic review and design in accordance with anthropometric dimensions, physical features of 160 students of art and 40 students of a technical and vocational school were measured. Then data was analyzed by SPSS 18 software.
Results: According to the results, about 70 percent of the students did not feel comfortable with the features of former chair and table, except for the length of the thigh. There was no significant difference between the different educational foundations in the vocational schools and finally, with the help of tonality features, the drawing table and chair were designed which except for the height of the sitting space, in other indices, there was a 100% correlation with the dimensions of the student's body.
Conclusion: In this study, there was a lot of dissatisfaction among students due to the lack of matching these educational materials with their physical dimensions which has caused physical, mental and psychological damage and poor quality of education. At the end of the study, through ergonomic design, matters of satisfaction, sustainability and reduced production costs and also the reasons for students' dissatisfaction with the drawing table and chairs is presented.

Background and Objectives: Musculoskeletal disorders are common in students and several causes may be considered for them. The aim of this study was to investigate the relationship between school furniture dimensions and trunk posture with musculoskeletal disorders in students of the sixth grade of elementary school in Karaj.
Methods: In this cross-sectional study, 346 boy students in sixth grade of elementary school in Karaj were selected. A flexible ruler was used to measure thoracic kyphosis and lumbar lordosis angles. A 50-centimeter metal ruler was used to record ergonomic and anthropometric data of the students. Spearman’s correlation test was run to analyze the collected data at the significant level of 0.05.
Results: The results showed that only 18%, 12% and 50% of desk height, seat depth and seat height measures were at normal ergonomic conditions, respectively. A negative significant correlation was observed between seat depth and total Nordic score (P<0.05).
Conclusion: It seems that school furniture dimensions in sixth grade boy students of elementary school in Karaj were not in acceptable condition. So, we suggest that ergonomics standardization of school furniture should be considered to prevent its possible consequences.

Background and Objectives: Sewing is one of the occupations where the prevalence of musculoskeletal disorders is high. Sewing conditions at the workstation have made tailors face musculoskeletal injuries in various areas of their body, particularly pain in the neck, shoulder, and upper back and even waist. The purpose of this study was to evaluate the effect of a workstation designed for tailoring considering the results of previous studies on the neck and shoulder muscles of users by electromyography.
Methods: In this interventional analytical study, the activity levels of four superficial neck and shoulder muscles (meridian, anterior deltoid, middle deltoid, posterior deltoid) were Electromyographed on 33 participants (male and female) at two new and custom designed workstations.
Results: There was a significant difference in the amount of muscle activity in the new and existing workstations (P<0.05). But there was no significant difference between the different modes of the new workstation.
Conclusion: All four muscles were less active at the new workstation than the conventional workstation, meaning that the designed workstation was able to reduce neck and shoulder muscle activity during work.

Background and Objectives: Macro Ergonomics is a socio-technical approach that deals with organizational, and work system design, as well as the design of human-machine, human-environment, and human-job interactions. Researches show that workplace macroeconomic’ conditions have undesirable effects on employees’ health, and hospital staff experience high levels of occupational stress and high prevalence of musculoskeletal disorders. This study aimed to investigate the relation between macroeconomic’ condition and prevalence of musculoskeletal disorders as well as outcomes of job stress among employees of hospitals affiliated to Urmia University of Medical Sciences.
Methods: This study was a descriptive cross-sectional study and 350 employees who randomly were selected from 5 hospitals participated in this study. Macro-ergonomic, Nordic and job stress outcomes questionnaires were used for data collection. Descriptive statistics, ANOVA and Chi-square tests were applied for data analysis.
Results: The findings of the present study indicated that out of 350 participants 217 (62%) were female and 168 were nurses (48%). Their mean age was 36.63 (±8.13) years and their average work experience was 11.53 (±7.65) years. The results of ANOVA test showed that the status of macro-ergonomics was significantly different in hospitals and hospital 1 had favorable condition. The majority of musculoskeletal disorder symptoms were reported in the neck (75.7%), hip, and waist (73.7%). The average score of job stress outcomes for the participants was lower than favorable limit. Macro-ergonomic’ conditions had significant associations with musculoskeletal disorders and job stress’ outcomes.
Conclusion: Based on the results of the current study, macro-ergonomic conditions had significant effects on musculoskeletal disorders and job stress outcomes. Interventional efforts should focus on organization and developing macro-ergonomic training programs to reduce musculoskeletal disorders and job stress and improve job conditions in hospitals.

Background and Aims: Ergonomics is associated with the study and systematic design of the workplace to improve human health and well-being. The health and well-being of employees are influenced by a variety of factors. Nature is a new paradigm in occupational ergonomics that has not been well explored in the main texts of ergonomics in relation to human well-being. Therefore, the main purpose of this study was to investigate the results of joining with nature on staff health, especially well-being in the form of a systematic review study.
Methods: By searching articles published from 2000 to 2019 in the field of Biophilic design, 25 articles were selected for the present systematic study based on the research criteria. Non-English language articles excluded.
Results: The results of this study showed that Biophilic design is associated with improved human well-being, performance, concentration and stress reduction.
Conclusion: Organizations, with the help of ergonomists, should consider such changes in the workplace, and nature-based solutions as strategic programs for improving well-being rather than merely applying a temporary strategy that changes the physical condition of a building or its landscape.

Background and Objectives: Using anthropometric characteristics in the ergonomic design of workstations can be useful in the prevention and reduction of musculoskeletal discomfort and in office-work environments. The purpose of this study was to determine the anthropometric dimensions of Hormozgan province gas department staff to design desks and chairs for computer work based workstations.
Methods: This is a descriptive-analytical study for measuring 36 anthropometric variables of 121 Hormozgan province gas company staff selected by cluster random method. After collecting anthropometric data considering ergonomic design criteria, dimensions of desk and office chairs are designed.
Results: Participants were 80.2% male and 19.8% female with a mean age of 35.11 and a standard deviation of 6.6 between 25 and 59 years. The mean and standard deviation of height measured was 170.7 and 8.06 cm, respectively. Anthropometric results are shown separately by gender and percentile in the tables. Dimensions of chair and office desk are designed based on obtained data.
Conclusion: The presented anthropometric desks can be used in future studies and designs. Also, the dimensional characteristics of the furniture provided can be a practical guide for designing and manufacturing office workstations.

Background and Aim: Agricultural combine harvesters play a crucial role in cereal productions. A combine operator performs almost all harvesting activities in seated posture. As an interface of the biomechanical system of operator’s body and combines’ mechanical system, seat has major effect on operator’s safety, health, and comfort. A successful design of seat is not achievable without considering the anthropometric characteristics of user population in geometric design. In current study, the accommodation of common harvesting combines’ seat with Iranian operators’ body dimensions has been investigated.
Methods: This study was conducted in Bijar, the widest county of Kurdistan province in the west of Iran. Eight anthropometric dimensions including weight, stature, shoulder height, elbow rest height, popliteal height, buttock-popliteal length, shoulder breadth, and hip breadth were measured on a sample of operators. The accommodation of seat pan width, upper backrest width, lower backrest width, seat height, armrest height, seat depth, and backrest height were investigated based on logical equations.
Results: There was a considerable mismatch between evaluated combine seats and the anthropometric dimensions of operators. Selecting 440, 370, 440, 410, 260, 430, and 415 mm for respectively seat pan width, upper backrest width, lower backrest width, seat height, armrest height, seat depth, and backrest height can increase the match percentage to a range of 62.2% to 100%.
Conclusion: The dimensions of available combine harvester seats are not suitable for Iranian population. However, considering the anthropometric dimensions of operators can improve the seats ergonomically. It should be noted that a design based on corresponding national and international standards cannot guarantee the geometrical accommodation of seats.

Background and Aim: A good work environment is a place where one can feel relaxed and focused. In the field of environmental psychology, color is one of the environmental factors that greatly influence human perception and behavior. The purpose of this systematic review study was to investigate the effect of color on work environment.
Methods: This article is a systematic review study. Full-text and English-language articles published in PubMed, Scopus, Science Direct, Google Scholar were searched using the following keywords: Color perception, color ergonomics, color psychology, color effect, mental health and Workplace. The search was without time limit, and 45 eligible articles were reviewed.
Results: Initially, 262 articles were identified from different databases. Among them, 93 articles met the criteria for entering the study. After that, 48 articles were removed from the study due to lack of experimental studies and 45 articles were selected for final review. A total of 18 studies focused on color priority, 25 studies on mood and emotions, 6 studies on health outcomes, and 19 studies on the effect of workplace color on work-related outcomes. The results showed that color has a significant effect on emotions (eg mood), well-being (eg stress, comfort, well-being) and performance (eg productivity, creativity).
Conclusion: Workplace color should be considered as one of the main ways to promote the (mental and physical) health of individuals.