Correlation between BMI and motor coordination in children

Objectives: To analyze the association between motor coordination (MC) and body mass index (BMI) across childhood and early adolescence.

Design: This study is cross-sectional.

Methods: Data were collected in 7175 children (boys n=3616, girls n=3559), ages 6-14 years. BMI was calculated from measured height and weight [body mass (kg)/height (m(2))]. Motor coordination was evaluated using Kiphard-Schilling's body coordination test (KTK). Spearman's rank correlation was used to study the association between BMI and MC. A Kruskal-Wallis test was used to analyze the differences in MC between children of normal weight, overweight and obese children.

Results: Correlations between MC and BMI were negative and varied between 0.05 and 0.49. The highest negative correlations for both boys and girls was at 11 years of age. There was a general pattern of increasing negative correlations in both genders from 6 to 11 years of age and then a decrease in correlation strengths through 14 years of age. In both boys (χ(2)((2))=324.01; p<0.001) and girls (χ(2)((2))=291.20; p<0.001) there were significant differences in MC between the three groups' weight status. Normal weight children of both sexes demonstrated significantly higher MC scores than overweight. Obese children in both sexes had the lowest MC scores among all three groups.

Conclusion: Motor coordination demonstrated an inverse relationship with BMI across childhood and into early adolescence. The strength of the inverse relation increased during childhood, but decreased through early adolescence. Overweight and obese children of both sexes demonstrated significantly lower MC than normal weight children.