Is High-Impact Sports Participation Associated with Bowlegs in Adolescent Boys?

The purpose of this study was to investigate whether the participation in load bearing sports is associated with significant knee alignment adaptations in adolescent boys, which might cause a higher risk for the development of knee osteoarthritis in later life. Five hundred twenty-one healthy boys (from 7 to 18 yr), selected from local primary and secondary schools, participated in the study. Two hundred sixty-five of them practiced competitive sports (track and field, field hockey, basketball, volleyball, tennis, badminton, and squash) for at least 3 h·wk(-1). The other remaining 256 boys did not practice any kind of sports. Genu varum/valgum was determined by measuring the intercondylar (IC) and intermalleolar (IM) distance with the subjects in a relaxed erect standing position. The IC and/or IM distance was measured using a caliper. Both measurements were combined to one parameter: the IC-IM distance. A one-way ANOVA was performed to analyze differences between the different age groups within the sporting and nonsporting boys separately. For each age group, the IC-IM distances of the sporting and nonsporting boys were compared by ANOVA with post hoc Bonferroni corrections. A comparison between the sporting and nonsporting boys showed that the sporting boys had a significantly higher degree of genu varum from 13 to 15 yr or older (P = 0.01). From the results of this study, it can be concluded that practicing load bearing sports in general is associated with the same knee varus alignment in adolescent boys as previously has been indicated in intense soccer-playing adolescents.