title: School Bag Weight and the Occurrence of Shoulder, Hand/Wrist and Low Back Symptoms among Iranian Elementary Schoolchildren.
abstract: BACKGROUND
  Schoolchildren usually use school bags to carry their school materials. Carry-ing heavy school bags can cause several problems such as musculoskeletal problems among schoolchildren. The aim of this study was to investigate the association between the weight of school bags and the occurrence of low back, shoulder and hand/wrist symptoms among pri-mary school children.
  
  
  METHODS
  This cross-sectional, descriptive-analytical study was conducted among a sample of 307 elementary school children in Tabriz, Iran. Data were collected using a questionnaire and from measurement of the school bag weight, body weight and height of each participant. Data were analysed using SPSS software.
  
  
  RESULTS
  The average load carried by schoolchildren was 2.9 kg, representing approximately 10% of the children's body weight. Girls and lower grade children carried a greater percent-age of their body weights. Approximately 86% of the children reported some kind of muscu-loskeletal symptoms. The occurrence of shoulder, wrists/hands, and low back pain among school-children was 70%, 18.5% and 8.7%, respectively. The results of binary logistic regres-sion indicated that the school bag weight (expressed as a percentage of body weight) was only significantly associated with hand/wrist symptoms (P<0.05). Girls were more likely to com-plaint from low back pain than boys were. Age was significantly negatively associated with hand/wrist symptoms. Body mass index was also significantly associated with shoulder symptoms.
  
  
  CONCLUSIONS
  The results indicate a high prevalence of musculoskeletal symptoms among elemen-tary schoolchildren. Preventive measures and appropriate guidelines with regard to safe load carriage in schoolchildren are therefore needed to protect this age group.
authors.affiliation: Department of Occupational Health, Faculty of Health and Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Iman
authors.initials: I
authors.lastname: Dianat
authors.affiliation: Faculty of Health and Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Zeynab
authors.initials: Z
authors.lastname: Javadivala
authors.affiliation: Faculty of Health and Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Allahverdipour
keywords: Children; Load carriage; Musculoskeletal symptoms; School bag; Weight limit