Does obesity influence foot structure in prepubescent children?

OBJECTIVE: This study examines the relationship between obesity and foot st ructure in prepubescent children. DESIGN: Field-based, experimental data on BMI (body mass index) and foot st ructure were collected for 431 consenting children from 18 randomly selecte d primary schools. SUBJECTS: Of the 431 participants, 62 obese (BMI > 95th percentile) and 62 non-obese (10th percentile < BMI > 90th percentile) children (age = 8.5 +/- 0.5 y) were selected. MEASUREMENTS: Height and weight were measured to calculate BMI. Static weig ht-bearing footprints for the right and left foot of each subject were then taken using a pedograph to calculate the Footprint Angle and the Chippaux- Smirak Index as representative measures of the surface area of the foot in contact with the ground. RESULTS: A significant difference was found between the Footprint Angle of the obese and non-obese subjects for both the left (t = 3.663; P < 0.001) a nd right (t = 3.742; P < 0.001) feet whereby obese subjects displayed a red uced angle. Chippaux-Smirak Index scores were also significantly different for both the left (t = - 6.362; P < 0.001) and right (t = - 5.675; P < 0.00 1) feet between the two subject groups where a greater score for the obese subjects was evident. A decreased footprint angle and an increased Chippaux -Smirak Index are characteristic of structural foot changes that have been associated with compromised foot function. CONCLUSIONS: Excess body mass appears to have a significant effect on the f oot structure of prepubescent children whereby young obese children display structural foot characteristics which may develop into problematic symptom s if excessive weight gain continues. Further investigation into possible c onsequences, particularly any effects on foot function, is warranted.