Iranian Journal of Ergonomics
Year:2016 | Volume:4 | Issue:3|Papers Count:8

Introduction: The progress of technology and modern technology has changed today's workplaces and imposed more mental and cognitive demands to workers. Control room is an example of these workplaces. Currently, assessment of mental workload is a key point in the research and development of human-machine relationships in workplaces. This study aimed to validate an analytical approach in evaluating demanded mental workloads for control room operators in Pars combined cycle power plant.Methods: This was a fundamental-practical and cross-sectional study. First of all, a task analysis was used to understand the operation steps of control room operators. Then, the Visual, Auditory, Cognitive, Psychomotor (VACP) technique was applied to determine the mental workload demanded for performing each step of the works. Finally, the assigned ratings of the VACP method were validated by the analysis of Pearson’s correlation with the answers of the NASA-Task Load Index (NASA-TLX) questionnaire, collected from the control room operators.Results: Based on the results, the correlation between the assigned ratings of VACP technique and the answers of the NASA-TLX questionnaire was positive and significant.Conclusions: Due to the high correlation between the assigned ratings of VACP technique and the answers of the NASA-TLX questionnaire, the proposed VACP technique, which can be carried out in the early stage of the design, was suitable as an analysis tool for predicting metal workloads of control room operators.

Introduction: Varicose veins in the lower limbs commonly occur in the general population and can negatively affect their quality of life. One of the high-risk jobs is the field hairdressers. The aim of this study was to investigate the effects of ergonomic interventions on quality of life of female hairdressers suffering from diseases in the lower extremities varicose veins.Methods: The study population was all female hairdressers of Hamadan Mahdieh clinic who were referred for medical examinations. Using simple random sampling method, 70 patients suffering from varicose disease were chosen and were classified to case and control groups. The intervention included an exercise protocol for the cases with varicose disease. The present study was quasi-experimental with pre-test and post-test and participants responded to Aberdeen varicose veins, chronic pain and muscle fatigue questionnaires, which were considered as indicators of quality of working life. Data was analyzed by paired sample t-test using of SPSS 16.Results: The results showed that ergonomic interventions were effective on the rate of varicose score, pain and swelling score as well as the score of muscle fatigue of left and right lower limbs in the case group. The average scores of varicose veins, pain and swelling, and left and right lower extremity muscle fatigue in the case group decreased respectively, 2.66 0.75, 2.4 and 1.2.Conclusions: With regard to the impact of exercise protocol on quality of working life in hairdresserd, the use of this protocol is recommended in patients with varicose veins disease.

Introduction: the quality of life of nurses and nurse aides is under the influence of various factors including the occupational ones, which affect the quality of their services. The purpose of this research was to investigate the occupational and demographic factors effective on the quality of life of nurses and nurse aides working in teaching hospitals affiliated to Kerman University of Medical Sciences.Methods: the present research was a cross-sectional one conducted in 2014 on 620 nurses and nurse aides. Simple random sampling method was utilized. The data were collected via the World Health Organization Quality of Life short form (questionnaire). Shift working, having a second job, marital status, length of marriage and having a shift working spouse were the independent variables of this study. Data were analyzed in SPSS 18 software using analysis of variance (ANOVA), Pearson's correlation coefficient, independent t and linear regression statistical tests.Results: the average age, length of marriage and work experience in hospital were 32.81±7.30 ± 10.61, 7.84 and 7.68±10.29, respectively. The number of children, having a second job, satisfaction from the hours spent with family, and belief in the effect of night work on family life were factors effective on quality of life (P>0.05). The highest relationship of quality of life was with environmental health (r=0.87, P=0.001) and the lowest was with social health (r=0.75, P=0.002).Conclusions: Avoiding to have a second job, scientific planning of shift work schedules and trainings relevant to life skills in shift workers would help improve the quality of life of nurses and nurse aides.

Introduction: Shift work, in addition to its effects on physical, psychological and social status, may impact on oral health. The aim of this research was to assess the relationship between shift work and oral health in nurses.Methods: This cross-sectional study was carried out on 120 nurses working in a hospital affiliated to Tehran University of Medical Sciences during 2015-2014. Oral health status and DMFT index (Decayed, Missing and Filling Teeth) was assessed by a dentist through clinical examination. Data were analyzed using SPSS 22 software, chi-squared test, independent samples t-test and multiple logistic regressions test.Results: The results showed that the means of DMFT index in shift work nurses and non-shift work nurses were 4.10±8.10 and 2.8±9.41, respectively. There was no significant difference between decayed, missing and filled teeth and periodontal DMFT index in both groups. Multiple logistic regression analysis revealed that age was a significant predictor of DMFT indictor (P<0.001). No significant relationship was found in DMFT index with gravid, parity, family income, anxiety and work experience.Conclusions: This study demonstrated that shift work was not an independent factor affecting oral health. However, regarding the DMFT index mean differences and nurses' job responsibilities, it seems necessary to pay more attention to this occupational group.

Introduction: Since faculty members are among the most important assets of higher education institutions, surveying and identifying factors associated with these sources that can be effective on their performance and stress have gained increasing importance. Accordingly, the present study was conducted to survey the relationship between personal accountability and job performance considering the mediating effect of skills and job stress among employees of the University of Shiraz.Methods: The statistical population of this study consisted of all of Shiraz University staff who had high school diploma, which included 726 individuals. A sample of 256 persons was chosen using stratified random sampling method. The research method was descriptive-correlative. Data were collected using Hochwarter et al. (2005) accountability, job performance (1990) of Paterson, House and Rizzo's (1972) Job tension and political skills, and Ferris et al. (2005) satisfaction standard questionnaires. The structural equation modeling (SEM) was used to study the relationship between the latent variables and the measured ones in conceptual model.Results: The results showed that job performance was affected by personal accountability; employees who had political skills had more accountability, which significantly affected their job performance. Job tension had a significant negative correlation with job performance.Conclusions: According to the results, political skills and job tension affected the relationship of individual's accountability with job performance. The results put emphasis on the necessity of reassessing the mediating roles of political skills and job tension in surveying the causal relationships of accountability with job performance.

Introduction: Musculoskeletal disorders (MSDs) are inevitable consequences of ergonomic principles neglect. The increasing use of computer by students may result in these disorders. Therefore, the present study was conducted to determine the prevalence of MSDs and evaluate the effectiveness of ergonomics training intervention among university students.Methods: This interventional and cross-sectional study was performed on a group of medical and paramedical students. Samples were chosen by simple sampling method. In the first stage, data were gathered by means of a self-made measurement and Nordic Musculoskeletal Questionnaire (NMQ). Furthermore, an educational booklet regarding the principles of ergonomics in computer use (educational intervention) was offered to the subjects. In the second stage of the study, the effectiveness of intervention was evaluated using a written exam and a quasi-objective structured clinical examination (quasi-OSCE) test. Data were analyzed by SPSS 15, as well as descriptive and analytical statistical indexes.Results: From 205 students participated in the first round of the study, the results showed that %66.44 of them (128 persons) reported at least one complain or limitation in their musculoskeletal systems during the past year. Less than %10 of the participants were aware about the considerations of ergonomics principals during computer use. After submission of the educational materials, their awareness about the ergonomics considerations in computer use significantly improved (P<0.001) and more than %95 of them had good or medium performance after the intervention.Conclusions: The training program was effective on the awareness of ergonomics principles in computer use. However, prevention of musculoskeletal disorders requires complementary measures such as elimination of risk factors and administrative controls.

Introduction: Advances in technology and the use of complex systems at work have imposed high mental workloads to operators; so, continuous monitoring of mental workload can help to prevent mental problems and maintain mental health. Therefore, this study aimed to investigate the impact of mental workload on physiological and subjective responses.Methods: This cross-sectional descriptive-analytical study was performed on 16 healthy university students in 2014 at a laboratory setting. Physiological parameters of surface electromyography and electrocardiography in six blocks (resting, high mental work, moderate, low, very low and recovery) were measured using NeXus4-. After performing each block, the NASA-TLX questionnaire was completed. Statistical analysis was conducted using SPSS software version 21.0. A %5 significance level was adopted in all the tests.Results: The results showed significant differences for the average score of NASA-TLX between the different levels of mental work load (P<0.05). Also, the analysis of repeated measures variance showed significant differences for heart rate and heart rate variability parameters in the six blocks (P<0.05), but no significant difference was observed for the shoulder muscles activity.Conclusions: Different levels of mental work load can impact on people's subjective responses and some of their physiological responses. Thus, in such workplaces, it will be necessary to conduct an ergonomic program to manage mental health.

Introduction: work engagement is a stable and positive state of mind associated with work, which protects against job burnout. This study was conducted to determine the contribution of goal orientation, perceived organizational support and Big Five personality traits in predicting job motivation of female teachers in Shahrekord, Iran.Methods: The design of the study was correlational-survey. The sample included 230 female teachers in Shahrekord, teaching in high school during 2014-2013. The sample of the study was selected by cluster sampling. To collect data, goal-orientation (VandeWalle, 1997), perceived organizational support (Eisenberger et al., 1986), five factor inventory (Costa and McCrae, 1985) and job work engagement (Shaufleie and Becker, 2003) were administered to the participants.Results: Correlation and step regression analyses were utilized to analyze the data. Findings of the study showed that there was a significant relationship among goal-orientation, perceived organizational support, Big Five personality traits and work engagement (P<0.01). Furthermore, multiple regression analysis revealed that linear combination of goal orientation, perceived organizational support and Big Five personality traits could predict work engagement of teachers (P<0.01).Conclusions: the present study indicated that different components of personality, goalorientation and perceived organizational support can create work engagement.