Objective. To determine the onset of low back pain (LBP) in schoolchildren and to investigate the role of mechanical and psychosocial factors as risk factors for its onset.
Methods. A prospective population-based cohort study was conducted of 1046 schoolchildren, aged 11 to 14 years at baseline, identified as being free of LBP, from 39 secondary schools in Northwest England. New onset of LBP at 1-year follow-up was measured.
Results. Children who reported high levels of psychosocial difficulties were more likely to develop LBP than their peers (relative risk: 1.6; 95% confidence interval: 1.1–2.3). An excess risk was, in particular, associated with conduct problems (2.5; 1.7–3.7). Similarly, children who reported high numbers of somatic symptoms at baseline were at greater risk of developing LBP: abdominal pain (1.8; 1.1–3.0), headaches (1.6; 0.97–2.8), and sore throats (1.5; 0.8–2.6). In contrast, we have been unable to demonstrate a strong association between daily mechanical load (schoolbag weight) and the short-term risk of new-onset LBP (highest versus lowest quintile: 1.2; 0.7–2.1).
Conclusions. In children who were initially free of LBP, adverse psychosocial factors and the presence of other preexisting somatic pain symptoms were predictive of future LBP, reflecting findings in adults. In contrast, there was little evidence of an increase in short-term risk associated with mechanical load across the range of weights commonly carried by children to school.