Standard growth of the foot arch in childhood and adolescence--derived from the measurement results of 10,155 children.

Background: The definition of flatfoot remains analytically vague. Toward the purpose of establishing the standard values of the foot length and arch height in childhood and adolescence, large-scale measurement and investigation of the foot arch were conducted using a three-dimensional foot-measuring device.

Methods: Measurements of foot structure were performed on 5311 boys and 4844 girls, for a total of 20,310 ft. of 10,155 children aged from 6 to 18 years during the 2006-2008 year period. The foot length (FL) and the navicular height (NH) were measured, and the arch height ratio (AHR (%)=NH×100/FL) was calculated.

Results: The FL in boys showed an extension from the age of 6 to 14 and nearly reached a plateau at 14 years old. In girls, the extension was observed from the age of 6 to 13, and the FL came to a plateau at 13 years old. The NH in boys increased from the age of 6 to 13. In girls, the NH increased from the age of 8 to 13. The AHR, presented a normal distribution, and no differences were observed in the distribution for all ages in boys and girls. In boys, the AHR was almost flat until 11 years old, but elevated in the 11-13 year age period. In girls, the AHR was almost flat until 10 years old, but elevated in the 10-12 year age period.

Conclusions: We are certain that the data demonstrating the normal growth of the foot contribute to the diagnosis and treatment of the failure of the foot to thrive.