Structural Changes in the Lower Extremities in Boys Aged 7 to 12 Years Who Engage in Moderate Physical Activity: An Observational Longitudinal Study

Background: Physical activity in children may provide health benefits. We sought to consider the practice of soccer as a possible major factor in the development of the lower limb. The study is based on 3-year data for a group of children who practice this sport. Methods: For 3 years we monitored 53 children who practiced soccer 3 times a week and had engaged in 2 years of continuous sports activity. Their mean ± SD age was 8.49 ± 2.01 years in the first year. Each year, Foot Posture Index, valgus index, subtalar joint axis, and Q angle for the knee were analyzed. Results: The mean ± SD Foot Posture Index scores ranged from 5.38 ± 1.79 in the right foot and 4.49 ± 1.67 in the left foot in the first year to 4.64 ± 2.51 and 4.34 ± 2.26, respectively, in the third year. The valgus index for the same period ranged from 14.058 ± 1.518 (right) and 13.888 ± 1.468 (left) to 13.098 ± 1.288 and 13.078 ± 1.078, respectively. In the knee, the Q angle ranged from 12.838 ± 1.988 (right) and 12.748 ± 1.688 (left) to 13.178 ± 1.458 and 13.268 ± 1.468, respectively. In the subtalar joint, the changes were 37.73% right and 30.19% left between the first and third years toward a neutral subtalar joint axis. Conclusions: These results show that although playing soccer might cause structural changes in the lower limb, these alterations should not be considered harmful because they may be influenced by age as well. (J Am Podiatr Med Assoc 107(3): 215-222, 2017)