Nonspecific back pain in children. A search for associated factors in 14-year-old schoolchildren.

Background: Nonspecific back pain in children is nearly as common as in adults but is associated with a number of age-specific risk factors including female gender, a family history of low back pain, a high level of physical activity, and prolonged sitting.

Objective: To investigate potential school-related risk factors for back pain in children, most notably schoolbag weight expressed as a percentage of body weight (relative schoolbag weight), whether the schoolbag is carried by hand or by a shoulder harness, how the child travels to and from school, and sitting positions.

Patients and methods: 123 eighth-graders, 58 girls and 65 boys, with a mean age of 14 +/- 0.6 years, completed an anonymous self-questionnaire during a school day involving six hours of classes. Their schoolbag was weighed on the same day.

Results: Most respondents traveled to and from school in a vehicle (70%), made one trip in each direction each day (75%), and carried their schoolbag by the shoulder harness (92%). The prevalence of back pain on the study day was 27.6%, whereas the cumulative prevalence for the last 12 months was 82.9% with 16.3% of respondents reporting a single episode of pain, 57.7% recurrent pain, and 8.9% chronic pain. A need for a physician visit for back pain was reported in 18.7% of cases, and 14.6% of respondents had missed school and/or sporting activities because of back pain. Female gender was associated with current back pain (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.2-6.1). A relative schoolbag weight of 20% or more was associated with a history of back pain (OR, 3.1; 95% CI, 1.0-9.2), and this effect was larger in children who traveled to and from school on foot and in those who carried their schoolbag in their hand. Sitting on the edge of the chair while completing the questionnaire was significantly associated with a history of a physician visit for back pain (OR, 3.1; 95% CI, 1.0-9.5). Neither handedness nor the position of the questionnaire on the table were significantly associated with back pain in our study population.

Conclusions: The findings from this cross-sectional study indicate a need for a longitudinal prospective study designed to identify etiologic and prognostic factors of back pain in adolescents, with the goal of devising preventive strategies likely to reduce the risk of low back pain in adulthood.