Iranian Journal of Ergonomics

Introduction: Driver fatigue is one of the major causes of accidents in roads. It is suggested that driver fatigue and drowsiness accounted for more than 30% of road accidents. Therefore, it is important to use features for real-time detection of driver mental fatigue to minimize transportation fatalities. The purpose of this study was to explore the EEG alpha power variations in sleep deprived drivers on a car driving simulator.

Materials and Methods: The present descriptive-analytical study was achieved on nineteen healthy male car drivers. After taking informed written consent, the subjects were requested to stay awake 18 hrs before the experiments and refrain from caffeinated drinks or any other stimulant as well as cigarette smoking for 12 hrs prior to the experiments. The drivers sleep patterns were studied through sleep diary for one week before the experiment. The participants performed a simulated driving task in a 110 Km monotonous route at the fixed speed of 90 km/hr. The subjective self-assessment of fatigue was performed in every 10 minute interval during the driving using Karolinska Sleepiness Scale (KSS). At the same time, video recordings from the drivers face and their behaviors were achieved in lateral and front views and rated by two trained observers. Continuous EEG and EOG records were taken with 16 channels during driving. After filtering and artifact removal, power spectrum density and fast Fourier transform (FFT) were used to determine the absolute and relative alpha powers in the initial and final 10 minutes of driving. To analyze the data, descriptive statistics, Pearson and Spearman coefficients and paired-sample T test were employed to describe and compare the variables.

Results: The findings showed a significant increase in KSS scores in the final 10 minutes of driving (p<0.001). Similar results were obtained concerning video rating scores. Meanwhile, there was a significant increase in the absolute alpha power during the final section of driving (p=0.006).

Conclusion: Driver mental fatigue is considered as one of the major implications for road safety. This study suggests that alpha brain wave rhythm can be a good indicator for early prediction of driver fatigue.

Introduction: High prevalence of neck pain has become an important health complain among dental practitioners which is followed by reduced working performance, burnout and early retirement. The purpose of this study is to assess the relationship between individual and occupational risk factors as well as forward head posture (FHP) with dentist’s neck pain and to determine the priority of these factors in the development of the neck pain.

Material and Methods: In this cross - sectional study, 70 dentists of two dental centers in Tehran were examined with clinical testing of FHP. Individual and job characteristics were collected by means of a questionnaire. The visual analog scale (VAS) was applied in order to determine the severity of pain in various parts of the body. Spearman and Pearson correlation coefficient and multiple linear regressions were used to examine the relationship and effect of the studied variables in creating the neck pain.

Results: According to the results, neck was the most painful part of the body (66.6%). Indeed, 40 (57.1%) of participating dentists were suffering from the forward head posture. The results of the multiple linear regression showed that the FHP with the standard coefficient (β= 0.64) was the most influential factor in predicting the incidence of neck pain.

Conclusion: The FHP has a greater impact than any other individual and job factors in creating neck pain. It may be concluded that awkward neck posture is the most important risk factor for neck pain in static sitting jobs such as dentistry.

Introduction: Job burnout can have negative effects on organizations and their employees. This study tried to investigate the relationships between job burnout and occupational stress, the four dimensions of organizational justice, personality characteristics, role clarity, and role overload.

Material and Methods: All full-time employees of the Regional Electric Company of Kerman (n = 200) were selected as the study sample. Finally, 138 usable questionnaires were collected. Previously designed questionnaires were used to measure work overload, occupational stress, role calrity, and organizational justice and respect. Maslach Burnout Inventory and NEO were also administered. Pearson’s correlation and multiple regression analyses were applied to analyze the data. All analyses were performed using SPSS 16.0.

Results: Job burnout was significantly related with occupational stress, distributive justice, extraversion, role clarity, role overload, organizational respect. Multiple regression analysis suggested distributive justice, overload, procedural justice, and occupational stress as the best predictors of job burnout. These factors explained 48% of the variance in burnout.

Conclusion: According to the results of this study, policymakers and planners of the organization are recommended to pay more attention to parameters contributing to job burnout. This will prevent job burnout among the personnel and promote organizational efficiency.

Introduction: Work-related fatigue is a source of concern, even in most industrialized countries. One of the most important factors influencing an employee’s physical and mental condition is the degree to which employees are able to recover from fatigue and stress after work. Factors such as workload can cause fatigue in workers. The aim of this study was using the need for recovery scale to assess workload in mine workers and its relationship with demographics.

Methods: In this cross-sectional study, 80 workers of a mine were surveyed. The data gathering tools used in this study were demographic characteristics questionnaire and the need for recovery scale. The scale assesses the workers workload with 11 two-optioned phrases. Mean, standard deviation, and Pearson’s correlation coefficient and ANOVA tests were used in order for data analysis.

Results: Mean (SD) score of the need for recovery scale was 55.22 (23.93), indicating moderately high workload in the workers. A total of 58.7% of workers experienced high levels of workload. Among the demographics, only body weight had a significant relationship with the need for recovery score (P value = 0.043).

Conclusions: Due to the relatively high need for recovery in the study population, solutions should be employed, such as reducing the workload, use of work-rest schedules, performing heavy tasks within teams, and providing conditions for proper and enough recovery after work, which can increase health conditions of workers.

Background and Objectives: The progress and rebound of organizations depends on their productivity. Many factors affect the organization’s productivity; identifying these factors the organization’s deterrence can be prevented. In this study, the relationship between job burnout and employee productivity has been investigated.  
Methods: This research is applied and its statistical population is 1265 people in Shariati and Kharazi hospitals. 294 of these employees were selected by Convenience sampling method considering the Cochran formula. Data was collected using the Maslach Burnout Standard Questionnaire and Hersey and Goldsmith Human Resources productivity Standard Questionnaire. Pearson correlation test and SPSS18 was used to analyze the data.
Results: The results of data analysis showed that burnout, emotional exhaustion, depersonalization and reduced personal accomplishment with -0.82, -0.86, -0.83 and -0.85 correlation values, respectively, have a reverse and meaningful relationship with employee productivity of Shariati and kharazmi Hospitals employees.
Conclusion: Since the results showed that burnout and its dimensions have a significant relationship with productivity of Shariati and Kharazmi Hospitals in Isfahan, it is necessary for organizations to apply measures to reduce the feeling of burnout in the staff. The results of this study are consistent with the results of other studies. At the end of the study, were presented several research proposals based on the results of the study.

Background and Objectives: Design of work environment is one of the factors that can affect performance and efficiency of employees. Human’s productivity has different dimensions that may be affected by environmental factors and internal factors such as demographic characteristics. Therefore, this study was designed to investigate the relationship between environmental and demographic factors with productivity of employees of Azad University of Shiraz.
Methods: In this cross-sectional study, out of 360 (all of the employees of Islamic Azad University, Shiraz branch)186 subjects were selected as a sample through convenience sampling. The data collection tools were demographic information questionnaire, Physical Work Environment questionnaire and Hersey-Goldsmith’s productivity questionnaire. Pearson correlation coefficient was used to measure the relationship between quantitative variables with productivity separately. Multiple linear regression analysis was used to examine the relationship between demographic and environmental variables.
Results: The results showed that there was a significant relationship between the factors of work environment design (furniture, noise, temperature, lighting and spatial arrangements). Also, there was a significant relationship between the levels of education with productivity score, so that people with a PhD level had a higher level of productivity than the participants with lower education. Also, the simultaneous relationship of demographic and environmental factors with productivity was significant for spatial arrangements.
Conclusion: The proper design of the work environment is related to employees’ productivity of Islamic Azad University of Shiraz. This can be affected by the demographic characteristics of individuals. However, the simultaneous effect of both factors with productivity showed that spatial arrangements has a considerable effects on productivity.