Abstract
The aims of this study were as follows: (1) to assess how foot posture and morphology assessments change according to body mass index (BMI) status; (2) to determine which body composition parameter (BMI or waist circumference) correlates better with the foot posture index (FPI), arch height index (AHI), and midfoot width (MFW) in children. Foot morphometry (FPI, AHI, and MFW) and body composition (BMI and waist circumference (WC)) were assessed in a cross-sectional study of 575 children (mean age = 7.42 ± 1.67 years; 53.27% female). When comparing BMI groups, an increase of 8.3% in AHI and 13.6% in MFW (both p < 0.0001) was seen. In linear regression analyses, BMI and WC were positively associated with MFW explaining together 64.8% of its variance. Noteworthy, MFW is the most related to body composition parameters. CONCLUSION: Foot morphology assessed by FPI, AHI, and MFW differs among BMI categories in children. Noteworthy, WC correlates better with foot measures than does the more commonly used BMI, and more importantly the MFW is the foot measure best explained by children's body weight. Since foot morphometry is different among different BMI groups, children would benefit from shoes with different patterns (thinner and wider), as well as a good system to adjust midfoot height. WHAT IS KNOWN: • Children who are overweight and obese have flatter feet, when assessed using footprints. • Up to 72% of people have incorrectly fitted shoes. WHAT IS NEW: • Children with underweight have thinner and flatter feet than children with normal weight, while children with overweight and obesity have wider and higher arched feet. • Body weight is related to foot shape, which has relevance for footwear manufacturers.