The growth of foot arches and influencing factors

Background Foot arches are important components for body support. Foot arch deformity caused by growth abnormalities cause serious limitations in daily activities. Objectives To determine the patterns of foot arch growth, factors influencing foot arch growth, and the timing for intervention in errant growth patterns. Methods A cross-sectional study evaluated the foot arches of children aged 0-18 years according to age and sex. Subjects included had no evidence of physical abnormality other than flat foot, knockknee, or bow leg. Subjects were grouped per year of age. Data on foot arch class, age, sex, weight, height, medial intercondylar distance, and medial intermalleolar distance were recorded. Chisquare test, correlation, binary and linear regressions, general linear model, and contrast matrix were performed. Results In 8376 children aged 0-18 years, flat foot grade 3 had stable proportions in all age groups. Flat foot grade 2 and 1 had smaller proportions in older age groups than in younger ones. The proportions of normal foot was greater in older age groups. Boys at the age of 7 and girls at 9 have a small percentage of pes cavus. The mean foot arch measurements were consistent with flat foot grade 2 at age 0-3 years, flat foot grade 1 at 4 years, and normal foot at age 18. Median foot arch measurement of children 0-10 years old was consistent with flat foot grade 1, while that of children 11 years old was consistent with normal foot. Age and height gave positive influence. Based on these measurements we infer that the optimal time for intervention is 0-7 years for boys and 0-3 years for girls. Conclusion The proportion of flat foot grade 3 is stable throughout age groups, that of flat foot grade 2 and 1 are smaller in older age groups, and that of normal foot is greater in older age groups. Overgrowth happens in very small percentages after age of 7 in boys and 9 in girls. Age, sex, height, weight, and growth of the knees are influencing factors