We analysed static footprints of 2300 children between the ages of four and 13 years to establish the influence of footwear on the prevalence of flat foot. The incidence among children who used footwear was 8.6% compared with 2.8% in those who did not (p less than 0.001). Significant differences between the predominance in shod and unshod children were noted in all age groups, most marked in those with generalised ligament laxity. Flat foot was most common in children who wore closed-toe shoes, less common in those who wore sandals or slippers, and least in the unshod. Our findings suggest that shoe-wearing in early childhood is detrimental to the development of a normal longitudinal arch. http://www.ncbi.nlm.nih.gov/pubmed/1624509