Journal of Health and Safety at Work

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Introduction: Eye discomforts and headache are prevalent among computer users. The aim of present study was to determine eye discomforts and headache associated with computer use among dormitory students of Tehran University of Medical Sciences.

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Material and Method: In this cross – sectional study, data were collected using MIRTH (Musculo skeletal Injury Reduction Tools for Health and Safety) questionnaire. The results were Analyzed using SPSS Software and with descriptive statistical indexes as well as correlation test.

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Result: of the 744 distributed questionnaires, 631 students completed the questionnaire (84.4%). The mean age for the studied population was 22.72± 3.6 years. The relative frequency of eye discomforts for the female and male student was 76.38% and 70.11% respectively. The correlation test showed significant relationship between eye discomforts as well as headache with gender, work hours’ with a computer per day and glass use (P-V < 0.05). Also, the correlation between eye discomforts and headache was statistically significant (P-V < 0.01).

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Conclusion: Eye discomforts and headache relating to the computer uses are prevalent among students. The condition is more prevalent among females and prolonged computer users. Interventional and training programs should be considered to prevent and reduction of related problems.

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Introduction: Nowadays, computers are integral component of all workplaces. Moreover, employees healthstatus is directly associated with their occupational stress level. The aim of the present study was to investigative the effect of ergonomic training and intervention on reduction of occupational stress among computer users in welfare organization in Rasht city.

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Material and Method: In this semi experimental study, 283 female computer users, who were 30-40 years old with work experience of 5-15 years, were chosen as sample. The participants had at least one year experience of using computer and they had worked 3-4 hours with computer daily. The Osipow occupational stress questionnaire (1987) with Cronbach alpha 87% was applied for estimation of occupational stress. Then, 46 participants with moderate to high level of stress were selected and randomly divided into case ad control groups. Participants in a case group received practical and theoretical ergonomic training and also interventions (including armrest, foot rest, cushion, posture correction, reduction o work time duration, adjustment of the seat height according to individuals height, adjustment of eye-monitor distance). Finally, the obtained data were compared to those of control group, using covariance.

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Result: According to covariance analysis, ergonomic training and interventions lead to reduction of occupational stress of computer users.

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Conclusion: Training computer users and informing them of the ergonomic principals and also providing interventions such as correction of posture, reducing duration of work time, using armrest and footrest would have significant implication in reducing occupational stress among computer users.

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Introduction: Nowadays, working in any computer work stations, named visual display terminal (VDT), was widespread and has become popular in our lives. Due to the increasing trend of using computers in the administrative and social institutions, prevalence of eye-related signs of working with computers is still increasing and it is one of the most important health issues. Computer jobs are low-mobility and require little energy to do physical work, but require more cognitive processing and mental focus. Visual fatigue is an occupational hazard for people working with computers. Eye fatigue has symptoms such as headaches, job discomfort, and eye pain the purpose of this study was to have a systematic review on eye fatigue, dry eye and eye blink among people working with visual terminals.  
Material and Methods: Internet search databases and search engines were used to find articles with focusing on the impact of risk factors on eye indexes on computer users. In this study, related articles were obtained from websites, including: PubMed, Google Scholar, Scopus and Web of Sciences. The keywords were used to search in these websites were: computer user, eye fatigue, dry eye and eye blink. Accordingly, after finding 115 relevant articles from the related sites, 17 articles were finally selected.
Results: Findings show that using computer cause many problems in the eye. Duration of using the computer, the type of work with the computer, the mental load, the distance from the monitor, and also long-term use of the computer without break in during work can cause dry and fatigue eye in users, which is one of the most common ocular problems among computer users.
Conclusion: According to the finding and results recommended to reduce of dry and fatigue eye, distance of users from the monitors, be more than 50cm, use 20-20-20 law to rest user’s eyes, and  Positioning the monitor be 15-20 degrees below the user’s line of sight. Also, too much focus on the screen reduces blinking and resulting in dry eyes. In order to prevent dryness of the surface of the eye, it is recommended that the eyelid be optional even if possible. Increasing the contrast of the monitor can be helpful in reducing stress and strain on the eye while working with a computer and using glasses instead of lenses to correct refractive errors and one of the ways to control and improve dry eye is using artificial tears by computer users.

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Introduction: Work-related musculoskeletal disorders (WMSDs) are one of the most important causes of absenteeism, increased costs and human injuries, which are very common in computer users. The purpose of this study was to investigate the effect of 8 weeks of corrective exercise on reducing the prevalence of musculoskeletal disorders (MSDs) in computer users working in a gas company.
Material and Methods: This cross-analytical study was conducted on 101 computer users working in a Gas Company in Qazvin city in 2019. Fourteen people participated in 8 weeks correction training intervention program (16 sessions in 1 hour and 2 times a week). Nordic questionnaire and body map were used in order to investigate the prevalence and severity of MSDs. The data were analyzed using Kolmogorov-Smirnov, Cramer V, McNamar, Paired sample t-test and Wilcoxon tests in SPSS version 23 software.
Results: The most common disorders were shoulder (64.3%), waist (42.9%) and neck (35.7%) regions among computer users during the last week before intervention. The prevalence of MSDsby strength and flexion exercises in neck and shoulder regions with 95% and 99% confidence showed a significant decrease before and after intervention. The incidence of discomfort in the waist region decreased by 35.8% after intervention and in other regions decreased by at least 7.1%.
Conclusion: The results of this study showed that implementation of corrective training intervention program by exercise specialists can increase muscle stretch and consequently decrease the prevalence of MSDs7.1%- 64.3%.

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Introduction: Low back pain is one of the most common musculoskeletal disorders leading to disability around the world. Several studies have suggested that prolonged computer/ laptop work contributes to the development of low back pain and discomfort. The results of the studies conducted on the association of back discomfort and muscle activity are contradictory. Thus, the present study aims to evaluate the relationship between the activity level and relative rest time of the trunk muscles with back discomfort while working with a laptop in a sitting position.
Material and Methods: First, 20 young healthy males performed laptop work including mouse work and typing in conventional and ergonomic setups. In the ergonomic setup, the screen height and keyboard placement were specifically adjusted for each individual. In addition, the electromyographic activity of the lumbar erector spinae, right and left multifidus and transversus abdominis, rectus abdominis, external oblique muscles, and the posture of the lumbar spine were recorded in the first and last two minutes of an 8-min task. After the end of each task, the participants scored their back discomfort.
Results: The results showed a positive correlation (r=0.57 and p=0.009) between back discomfort and the EMG amplitude of the lumbar erector spinae muscle. In addition, back discomfort was negatively correlated to the relative rest time of the multifidus muscle (r=0.50 and p=0.023), and a positive correlation was reported with the relative rest time of the transversus and rectus abdominis (r=0.47, p=0.039, and r=0.45, p=0.049, respectively).
Conclusion: The relative rest time of the trunk muscles may be a better index than that of the EMG amplitude to highlight the risk factors for back discomfort. However, a causative link between muscle activity and discomfort cannot be implied from this study. The current results do not undermine the role of other factors associated with the increased level of discomfort during sitting.

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Introduction: Nowadays, excessive computer use in the workplace has raised concerns about the health status of VDT workers, particularly complaints about eye discomforts. Due to the importance of the eyelids and eye closure parameters on eye health during computer works and the direct effect of monitor height on these parameters, this study was aimed to examine the effect of different monitor heights adjustment on the eye indicators and eye discomfort among participants.
Material and Methods: In this study, any changes in the eye indicators including blink rate, the eye blink opening and closing time, the blink opening rate in three different monitor heights (standard, low, and high) were examined among 11 participants. The blink rate and the eye blink opening and closing time were measured and evaluated using videotaping and analyzing by an image processing software, developed in this study. Participants were also asked to complete a questionnaire for eye fatigue assessment due to daily computer uses.
Results: Results showed that the highest rate of eye blink was at the standard height of the monitor, and this rate was significantly different at three different heights of monitors (high, standard, and low) (p<0.05). The lowest blink rate was observed at low and high heights with an average of 7.3 and 7.8 and the highest blink rate at standard height with an average of 8.9 blink per minute, respectively. Meanwhile, image processing and analyzing of eye surface showed, in average, 16% decrease in the opening rate of the eye surface by decreasing the height of the monitor, and 15% increase by increasing it, relative to the standard mode of monitor.
Conclusion: To protect users from computer-related eye strain, it is recommended to correct monitors height to the standard height along with typing and data entry training for keyboarding skill development and minimizing working times as a result. What is more, a proper work-rest schedule when working with computer can be considered as an effective countermeasure to prevent from eye strain.

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Introduction: Computer vision syndrome (CVS) is one of the most common health concerns associated with the extensive use of computers, particularly in the working environment. Since recent studies have shown the high prevalence of CVS, it is necessary to have an appropriate tool for assessing this prevalence. The present research aims to translate the CVS questionnaire and analyze its validity and reliability and assess the incidence of this condition among the staff members at Tabriz University of Medical Sciences.
Material and Methods: The translation of the main questionnaire into the Persian version was carried out in three steps. Two coefficients including the content validity ratio (CVR) and the content validity index (CVI) were used to evaluate the content validity of the questionnaire. The reliability of the questionnaire was examined using two methods including internal consistency (Cronbach’s alpha) and test-retest. In total, 240 participants were asked to fulfill the questionnaire in order to investigate the prevalence rate of CVS among the staff members of Tabriz University of Medical Sciences. After removing the ineligible ones, 219 questionnaires were examined.
Results: The internal consistency coefficient and Cronbach’s alpha coefficient were 0.91 and 0.89, respectively. Out of a total of 102 women and 117 men, only 19 women and 21 men did not have CVS. Among the studied symptoms, eye redness (78.1%), burning (76.7%), and headache (74%) were the most prevalent in the statistical population. No significant relationship was observed between the final score of CVS and gender.
Conclusion: In terms of validity and reliability, the questionnaire was found to be satisfactory. The prevalence of CVS among the staff members of Tabriz University of Medical Sciences was high (81%). To determine the etiologies, further research is needed.

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Introduction: Due to the increase in the provision of electronic services to citizens in government offices, the number of computer users and the occurrence of musculoskeletal disorders have increased. Therefore, this study aimed to predict and model the complex relationships between the risk factors of musculoskeletal disorders in computer users working in government offices by an artificial neural network.
Material and Methods: The current cross-sectional study was conducted in 2020 on 342 employees of various government offices in Saveh city. First, the researcher visited the work environment to identify the problems and measure the environmental factors. Then, ergonomic risk assessment and psychosocial factors were evaluated using the Nordic questionnaire and the ROSA method. The effect of various factors in causing musculoskeletal disorders was investigated using a logistic regression test.Then the resulting data were collected and modeled by one of the neural network algorithms. Finally, artificial neural networks presented an optimal model to predict the risk of musculoskeletal disorders.
Results: The results showed that by increasing the level of social interactions, the level of demand, control, and leadership in the job, musculoskeletal disorders in men and women decrease. There was a significant relationship between the prevalence of musculoskeletal disorders and job demand, job control levels, social interaction levels, leadership levels, organizational climate levels, job satisfaction levels, and stress levels, in addition between reports of pain in the neck and shoulder and wrist/hand region. There was a significant relationship with the overall ROSA score. Also, there was a significant relationship between the report of pain or discomfort in the neck area with the phone screen risk score, wrist/hand with the keyboard-mouse risk score, and shoulder, upper back, elbow, and lower back with the chair risk score. The accuracy of the presented model for predicting musculoskeletal disorders was also about 88.5%, which indicates the acceptability of the results.
Conclusion: The results showed that several factors play a role in causing musculoskeletal disorders, which include individual, environmental, psychosocial, and workstation factors. Therefore, in the design of an ergonomic workstation, the effects of the mentioned factors should be investigated. Also, predicting the effectiveness of each of the mentioned factors using an artificial neural network showed that this type of modeling can be used to prevent musculoskeletal disorders or other multifactorial disorders.