Relationship of flatfoot to physical performance and postural stability in children: The Yamanashi adjunct study of the Japan Environment and Children's Study.

Objective: This study examined the relationship between flatfoot, physical performance, and postural stability in 8-year-old children.

Methods: This study involved 196 children from the Japan Environment and Children's Study (JECS) and focused on foot morphology, postural stability, and physical performance using standardized sports tests. The Chippaux-Smirak index was used to evaluate the degree of flatfoot, which correlated with body composition, physical performance, and postural stability.

Results: The results showed that 8.6 % of boys and 3.9 % of girls had flatfoot, with boys exhibiting a higher frequency. A significant correlation was found between flatfoot and increased body weight and fat percentage. The study found no significant association between flatfoot and physical performance as measured by sports tests such as sprinting and jumping. However, a significant relationship between flatfoot and postural stability was observed, as children with more severe flatfoot exhibited greater postural instability, particularly girls. These findings suggest that although flatfoot does not correlate with physical performance, it is associated with decreased postural stability, which may reflect broader developmental issues in children with flatfoot.

Conclusion: These findings highlight the need for further research on the underlying causes of flatfoot and its effect on child development, particularly regarding the role of the nervous system in postural stability.