the frequency of musculoskeletal disorders in students of tehran, tehran, iran

background and objectives: musculoskeletal disorders are common among children. burden imposed on neck, shoulder and back areas by carrying schoolbags may result in musculoskeletal disorders in students. the aim of this study is to determine the frequency of musculoskeletal symptoms and factors associated with these symptoms in students of tehran.   methods: three hundred and forty students participated in this cross-sectional study. students were selected from five primary and middle schools in five different regions of tehran . musculoskeletal disorder examination was based on nordic questionnarie and body map was used to determine the location of musculoskeletal pain and discomfort. cluster sampling was applied to select the required statistical sample. data using independent t-test, were analysed with significant level of p<0.05.   results: most common musculoskeletal discomforts were observed in shoulders 37.9%, neck 28.5% and lumbar 17.4% areas. the differences between the avarage weight of schoolbag in those cases who had muculoeskeletal discomforts with those without such disorders, were significant (p<0.05).   conclusion: according to the results, there is a close relationship between the weight of schoolbag and musculoskeletal disorders in neck and/or shoulder and back in students. so, although it is believed that these disorders have different origin, carrying heavy schoolbags is very suspicious case in expressing these symptoms.