ABSTRACT
INTRODUCTION: In spite of the widespread use of automation in industry, manual material handling (MMH) is still performed in many occupational settings. The emphasis on ergonomics in MMH tasks is due to the potential risks of workplace accidents and injuries. This study aimed to assess the effect of box size, frequency of lift, and height of lift on maximum acceptable weight of lift (MAWL) on the heart rates of male university students in Iran. METHODS: This experimental study was conducted in 2015 with 15 male students recruited from Tehran University of Medical Sciences. Each participant performed 18 different lifting tasks that involved three lifting frequencies (1lift/min, 4.3 lifts/min and 6.67 lifts/min), three lifting heights (floor to knuckle, knuckle to shoulder, and shoulder to arm reach), and two box sizes. Each set of experiments was conducted during the 20 min work period using the free-style lifting technique. The working heart rates (WHR) were recorded for the entire duration. In this study, we used SPSS version 18 software and descriptive statistical methods, analysis of variance (ANOVA), and the t-test for data analysis. RESULTS: The results of the ANOVA showed that there was a significant difference between the mean of MAWL in terms of frequencies of lifts (p = 0.02). Tukey's post hoc test indicated that there was a significant difference between the frequencies of 1 lift/minute and 6.67 lifts/minute (p = 0. 01). There was a significant difference between the mean heart rates in terms of frequencies of lifts (p = 0.006), and Tukey's post hoc test indicated a significant difference between the frequencies of 1 lift/minute and 6.67 lifts/minute (p = 0.004). But, there was no significant difference between the mean of MAWL and the mean heart rate in terms of lifting heights (p > 0.05). The results of the t-test showed that there was a significant difference between the mean of MAWL and the mean heart rate in terms of the sizes of the two boxes (p = 0.000). CONCLUSION: Based on the results of this study, it was concluded that MAWL and heart rate are influenced by the variables of lifting frequency and the size of the boxes.
ABSTRACT
BACKGROUND: Many nurses have reported experiencing high levels of occupational stress in their work environment. Stress, as an outcome of stressful workplaces and tasks, affects nursing behavior in hospital wards. The objectives of this research were to determine the prevalence of occupational stress and mental health problems in nurses in the intensive care unit (ICU) at Shahid Mohammadi Hospital in Bandar Abbas in 2013 and to determine the relationship between occupational stress and mental health. METHODS: This cross-sectional study was conducted in 2013 on all of the nurses working in ICU at Shahid Mohammadi Hospital located in Bandar Abbas, Iran. Seventy-two nurses were selected as the population for this study, and all of them were female. Two questionnaires were used in this study, i.e., General Health Questionnaire-28 (GHQ-28) for assessing mental health and an occupational stress test for assessing job stress. Furthermore, the relationship between occupational stress and mental health was examined. One-way analysis of variance (ANOVA), independent samples t-test, and Pearson's product-moment correlation test were used to analyze the data. RESULTS: High and moderate levels of occupational stress were experienced by 83.9% and 10.7% of ICU nurses, respectively. The prevalence of mental disorders, somatic symptoms, anxiety, social dysfunction, and depression were 58.9, 60.7, 62.5, 71.4, and 10.7%, respectively. The findings of the independent samples t-test showed that somatic symptoms had significant relationships with age and working experience (p = 0.01). According to the independent samples t-test, there were no significant differences between somatic symptoms and working different shifts (p > 0.05). CONCLUSIONS: There was a high prevalence of occupational stress among ICU nurses. There was a significant relationship between occupational stress and mental health. Future interventions are needed to codify a comprehensive health program in this field to reduce occupational stress and enhance nurses' levels of mental health.
