Association between flatfoot and age is mediated by sex: a cross-sectional study

Introduction
Flatfoot (pes planus) is one of the most frequently encountered pediatric foot deformities. In spite of the numerous evidences for adverse implications of flatfoot to the locomotive system and musculoskeletal health of patients, in the continuum of developmental milestone, the age to which patients should be monitored for flatfoot remains debatable.
Aim
We investigated the prevalence and pattern of flatfoot in a Nigerian population ranging from 6 to 25 years of age in order to describe the triad of age-sex-flatfoot preponderance.
Material and methods
This was a cross-sectional study among 620 participants using the footprint method and the planter arch index – Staheli arch index criteria for flatfoot diagnosis.
Results and discussion
Flatfoot prevalence in the study population was 27.4%; children had the highest prevalence (28.3%) and adults had the lowest (20.0%). Most of the flatfoot was unilateral (60.0%) and was the flexible form (73.8%). The transition from childhood to adulthood was associated with a significant decrease in prevalence of flatfoot among the male participants, but there was no association between prevalence of flatfoot and age beyond 9 years among the female participants.
Conclusions
The incidence of flatfoot in the Nigerian population is high. Monitoring for flatfoot into adulthood is advisable particularly for the male patients.