Objective To investigate whether backpack weight is associated with back pain and back pathology in school children. Design Cross-sectional study. Setting Schools in Northern Galicia, Spain. Patients All children aged 12-17. Interventions Backpack weight along with body mass index, age and gender. Main outcome measures Back pain and back pathology. Results 1403 school children were analysed. Of these, 61.4% had backpacks exceeding 10% of their body weight. Those carrying the heaviest backpacks had a 50% higher risk of back pain (OR 1.50 CI 95% 1.06 to 2.12) and a 42% higher risk of back pathology, although this last result was not statistically signifi cant (OR 1.42 CI 95% 0.86 to 2.32). Girls presented a higher risk of back pain compared with boys. Conclusions Carrying backpacks increases the risk of back pain and possibly the risk of back pathology. The prevalence of school children carrying heavy backpacks is extremely high. Preventive and educational activities should be implemented in this age group.

This study shows that an inexpensive intervention directed to reduce the backpack weight and back pain might have a positive effect in schoolchildren.