Background:Low back pain caused by work, ranked the second after cardiovascular diseases, are among the most common reasons of patients’ referral to the physicians in Iran. This study aimed to determine the changes in back compressive force when measuring maximum acceptable weight of lift in Iranian male students.Methods:This experimental study was conducted in 2015 on 15 young male students were recruited from Tehran University of Medical Science. Each participant performed 18 different lifting tasks involving three lifting frequencies, with three lifting heights, and two box sizes. Each set of experiments was conducted during the 20 min work period using free-style lifting technique. The back compressive force evaluated with hand-calculation back compressive force method. Finally, Pearson correlation test, analysis of variance (ANOVA) and t-test were used for data analysis.Results:The mean of back compressive force (BCF) for the small and large boxes at a frequency of 1lift/min at heights of F - K height, were 1001.02 (±86.74), 1210.57 (±93.77) Ib, respectively. There was a significant difference between mean BCF in terms of frequencies of lifts (P=0.02). The result revealed significant difference between frequencies of 1 lift/min and 6.67 lift/min (P=0.01). There was a significant difference between mean BCF in terms of the sizes of the two boxes (P=0.001). There was a significant relationship between the BCF and maximum acceptable weight of lift in all test conditions (P=0.001).Conclusion:BCF is affected by box size, lifting frequency and weight of load.

The Aim of this study was to evaluate anxiety and pain related to dental treatment in children under the age of five years. This cross sectional study was carried out with 350 children of both sexes. Socioeconomic data, dental anxiety and dental pain experience, as well as the assessment of the child's oral health status, were obtained through a questionnaire answered by the child's parent or guardian. Dental anxiety was measured using the Dental Anxiety Question (DAQ). The prevalence of dental anxiety was 22.9% and that of dental pain was 6.8%. There was an association between these two variables (p<0.0001). There was also an association between dental pain, age, family income and assessment of oral health status. The poorest rating of the child's oral health and the lowest family income were correlated with the highest percentages of a history of dental pain. Dental anxiety was related to a history of dental pain in children under the age of five years.

Introduction: The importance of assessing and identifying ergonomic risk factors in the workplace among office workers has increased with the increase in occupational tasks of computer and increasing the risk of physical and mental disorders among its users. One of these factors is the usability of computer hardware and software. The purpose of this study was to evaluate the applicability of office automation software and to measure the fatigue and burnout of employees in an office and determine their correlation. Methods: In this study, in one of the health centers of Tehran City, staff fatigue, burnout and their use of office automation software using multidimensional job fatigue inventory (MFI-20), maslach burnout inventory (MBI), and the standard questionnaire was used to evaluate the usability of the software. Data were analyzed by SPSS 23 software. Results: The findings of this study showed that automation software was very useful for most users. According to the findings of this study, there was a significant negative correlation between software usability and emotional exhaustion dimensions, the reduction of personal inadequacy, general fatigue, and physical fatigue with correlation coefficients of -0.228, -0.511, -0.372 and -0.287, respectively.. The greater the usability of the software, the lower the level of employee fatigue and fatigue. Conclusion: The applicability of job software is effective in burnout and fatigue of employees. Therefore, the usable design of such web-based software should be considered by office systems and software developers