Lumbar mobility and low back pain during adolescence. A longitudinal three-year follow-up study in athletes and controls.

In this 3-year longitudinal study, we studied lumbar mobility and the occurrence of low back pain among 98 adolescents who were free of previous severe low back pain: 33 nonathletes (16 boys, 17 girls), 34 boy athletes (ice hockey and soccer players) and 31 girl athletes (figure skaters and gymnasts). During the followup, low back pain lasting longer than 1 week was reported by 29 athletes (15 boys and 14 girls) and by 6 nonathletes (3 boys and 3 girls). In multivariate analyses, participation in sports and low maximal lumbar flexion at the baseline predicted low back pain during the followup among boys; however, these factors accounted for only 16% of the variability between the groups with and without low back pain. Among girls, decreased range of motion in the lower lumbar segments, low maximal lumbar extension, and high body weight at the baseline were predictive of low back pain during the followup, accounting for 31% of the variability between the groups. The girls in the lowest tertile of maximal lumbar extension at baseline had a relative risk of 3.4 to have future low back pain compared with those in the highest tertile. We conclude that the low individual physiologic maximum of lower segment lumbar extension mobility may cause overloading of the low back among athletes involved in sports with frequent maximal lumbar extension and that it predicts future low back pain.