The flat foot is seen in children who walk by crushing the foot’s arch, the heel is in valgus (heel twisted outwards), and the forefoot is spread on the ground. In general, parents are worried about the appearance of their child’s feet. Sometimes they have found excessive wear on the inner edge of the shoe. More rarely, the child complains of abnormal fatigue when walking.

In adolescents of 12 or 13 years, contractures can be very painful, localized to the foot or the Antero-external face of the leg, causing lameness that prevents prolonged walking. Often, parents are worried because they have “flat feet” and do not want their child to suffer from it.

Diagnostic

The diagnosis of Flat feet (เท้า แบน which is the term in Thai) can only be made after three years. Indeed, in younger children, a bulky plantar pad gives a false impression of a flat foot. The feet are “plump”! The child is examined first, lying down. Achilles’ tendon brevity is sought by performing dorsiflexion of the foot after manually correcting the heel valgus.

The child is then examined standing up, if possible, on a podoscope which makes it possible to take and study the footprints or, failing that, on a hard surface.

Several signs attest to the presence of a flat foot:

• On the podoscope, the support surface is increased by the removal of the arch of the foot, the entire sole resting on the ground, and the internal edge of the foot having a support on the ground;
• The internal projection of the talus is palpated inside the inner edge of the foot. The astragalus moves in and out;
• The valgus of the calcaneus is seen by placing itself behind the child: the heel is thrown outwards;
• The forefoot goes outward (valgus);
• When the child rises on tiptoes, the heel valgus disappears, and the internal arch becomes hollow;
• Examination of the shoes shows abnormal wear on the inner and anterior edge of the sole.