An investigation of the factors affecting flatfoot in children with delayed motor development

• The prevalence of flatfoot is higher in preschool-aged children with delayed motor development than in those with normal motor development.
• Overweight children with delayed motor development are more likely to suffer from flatfoot.
• Children with both excessive joint laxity and delayed motor development are more likely to suffer from flatfoot.

This study investigated the prevalence of flatfoot in children with delayed motor development and the relevant factors affecting it. In total, 121 preschool-aged children aged 3–6 with delayed motor development (male: 81; female: 40) were enrolled in the motor-developmentally delayed children group, and 4 times that number, a total of 484 children (male: 324; female: 160), of gender- and age-matched normal developmental children were used as a control group for further analyses. The age was from 3.0 to 6.9 years old for the participants. The judgment criterion of flatfoot was the Chippaux-Smirak index >62.70%, in footprint measurement. The results showed that the prevalence of flatfoot in children with motor developmental delay was higher than that in normal developmental children, approximately 58.7%, and that it decreased with age from 62.8% of 3-year-olds to 50.0% of 6-year-olds. The results also showed that motor-developmentally delayed children with flatfoot are at about 1.5 times the risk of normal developmental children (odds ratio = 1.511, p = 0.005). In addition, the prevalence of flatfoot is relatively higher in overweight children with delayed motor development, and that in obese children is even as high as 95.8% (23/24). Children with both excessive joint laxity and delayed development are more likely to suffer from flatfoot. The findings of this study can serve as a reference for clinical workers to deal with foot issues in children with delayed motor development.