The Prevalence of Four Common Pathomechanical Foot Deformities in Primary School Students in Taichung County

Abstract

Background/Purpose. To investigate the overall prevalence of four common pathomechanical foot deformities, including flexible flatfoot, high-arch foot, hindfoot valgus and hallux valgus in primary school students in Taichung County and to determine the prevalence of these foot deformities in boys and girls in different primary school grades. Methods. We enrolled 18, 006 students (8883 boys and 9123 girls) from 14 primary schools in Taichung County. The arch index, hallux valgus angle, and hindfoot valgus angle in all students were obtained by footprint analysis. Grade-and sex-specific prevalence rates were calculated for each foot deformity. Using correspondence analysis, we constructed a mapping-based relationship between foot deformities, age, and sex. Results. The overall prevalence rates were 13.88% for flexible flatfoot, 1.32% for high-arch foot, 3.33% for hindfoot valgus and 1.40% for hallux valgus. Descriptive analysis indicated that flexible flatfoot was more common among boys in all grades and that high-arch foot was more common among girls in grades 5 and 6. We identified age as the primary predictive factor for all of the common foot deformities. Flexible flatfoot and hindfoot valgus were more frequent in boys and young girls. Hallux valgus was most common among older girls. Conclusion. This is the first study to determine the prevalence of flexible flatfoot, high-arch foot, hindfoot valgus and hallux valgus in a Chinese population. We found a strong association between flexible flatfoot and hindfoot valgus. Primary-school students with common pathomechanical foot deformities should be followed up on a regular basis to reduce the prevalence of foot deformity-related musculoskeletal problems.