Introduction: The hypothesis of this work is to demonstrate that the Flexible Flat Foot (FFF) in children is not affected for any kind of treatment. The objective is: 1.-Rate the evolution of FFF during growing. 2.- Evaluate the accuracy of diagnosis criterion. 3.-Appoint the optimal age to diagnose and treat the FFF. 4.- Evaluate the different kinds of treatment.

Material and methods: 242 children of both sex, aged between 3 and 5 years old, diagnosed of flexible flat foot. We compare three groups of treatment during three years. One group were treated with orthopaedic shoes and internal wedges, other with inserts, and the third were a control group. We evaluated: Clinical findings: age, sex, flat foot family antecedents, weight, degree of flat foot, valgus of ankle, age of begin to walk, ligament hiperlaxity, vicious direction of leg axis and erosion of shoes. Radiological measurements: An astragalus-1°metatarsian, Moreau and Costa-Bartani, and astragalus-calcaneus divergence angles, valgus of ankle according Viladot system. We perform a walking test with an electronic baropodometer “PEL 38” with 20 children of every group.

Results: An 85 % child of our series has been normalized with growing. The overweight and ligament hiper-laxity are the most predisponent family antecedents. The Jack Test is not a prognostic factor of FFF. The vicious direction of leg is not related with the FFF. The valgus of ankle is physiologic. X-ray are not reliable to diagnose a FFF in children, while the walking test give us dates about the dynamic behaviour of FFF.

Conclusions

– The flexible flat foot in children is normally corrected with growing and is a normal step of foot evolution.