Background:The incidence of heat stress is one of the most common problems in workplaces and industries. Many heat stress indices have been developed, and these indices have some disadvantages. The purpose of this study is to validate the perceptual strain index (PeSI) in experimental hot conditions.Methods:This study is of cross-sectional carried out on 15 men at five different thermal conditions (35°C, 30°C, 27°C, 24°C, and 21°C) in a climate chamber and on a treadmill at three levels of light (2.4 kph), medium (4.8 kph) and heavy activity (6.3 kph). Heart rate and oral temperature were respectively measured to calculate the physiological strain index. Also, thermal sensation and rate perceive exertion were respectively measured to calculate the PeSI. Finally, the correlation between the indices was analyzed using Pearson correlation test and regression analysis.Results:Pearson correlation test showed a high correlation (r = 0.94) between the PeSI and physiological strain index (P = 0/001). It was also observed a high correlation between the PeSI and the oral temperature (r = 0.78, P = 0/001) and the heart rate (r = 0.90, P = 0/001). In addition, there was found a moderate correlation (r = 0.71) between the PeSI and the wet bulb glob temperature (P = 0/001). However, there was no correlation between the PeSI and the body mass index (r = 0.0009, P = 0.79).Conclusions:The research findings showed when there is no access to other forms of methods to evaluate the heat stress, it can be used the PeSI in evaluating the strain because of its favorable correlation with the thermal strain.

Background: Mental workload is one of the factors that influence individuals' performance in the work environment as well as their efficiency and productivity. This study aimed to evaluate the effectiveness of the Rating Scale Mental Effort (RSME) for mental workload in nurses. Materials and Methods: This study was descriptive and cross-sectional conducted on 75 nurses. For assessment of mental workload, first NASA task load index (NASA-TLX) and then RSME were measured. After from data gathering, the data were analyzed using SPSS, descriptive statistics, Student's independent t-test, analysis of variance (ANOVA) and Pearson correlation test. Results: The results of the assessment workload using RSME and NASA-TLX index of nurses showed that nurses' workload was high. Pearson correlation test regression coefficient showed a good correlation between scores of RSME and NASA-TLX index (r = 0.72) (r 2 = 0.51). Also there was no significant association between age and work experience with mental workload score in RMSE (P = 0.09) (P = 0.08) and NASA-TLX index (P = 0.08) (P = 0.06). Student's t-test showed that no significant relationship was observed between sex and scores of RMSE (P = 0.08) and NASA-TLX index (P = 0.07). Conclusions: The results of this study showed that RMSE is a good method for assessing mental workload and there was acceptable correlation with NASA-TLX valid indices. RMSE index can be used to assess the mental workload.

Background: Musculoskeletal pain accompanied by psychological problems leads to reduced health efficiency. On the other hand, work-related anxiety and depression is another important factor that could result in reduced productivity in organizations and physical and mental problems in personnel. Musculoskeletal disorders (MSDs) are the most common occupational health problems that have high costs and lead to productivity loss in military personnel. The purpose of this study was to evaluate the association of anxiety and depression with MSDs among military personnel in 2016. Materials and Methods:This descriptive-analytic and cross-sectional study was conducted on 70 military personnel in July 2016 through convenience sampling method. The data collection tools used were the Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) and Goldberg Anxiety and Depression Scale. Data analysis was conducted using descriptive statistics, Pearson correlation test, and ANOVA in SPSS software. Results: The highest prevalence of MSDs was observed in the back (48%), thoracic spine (41%), and shoulder (37%). The Goldberg Anxiety and Depression Scale scores showed that anxiety and depression were at a medium level. The Pearson correlation test showed a significant correlation between anxiety (P = 0.01) (r = 0.79) and depression (P = 0.01) (r = 0.76), and MSDs; with increase in anxiety and depression, MSDs also increased. Conclusions:The results of this study showed that anxiety and depression have a direct relationship with MSDs. Therefore, interventions must be carried out for MSDs prevention such as reducing physical and psychological job demands, and reducing anxiety and depression level among military personnel.

No abstract

No abstract