Flexible Flatfoot Treatment with Custom Foot Insoles

The general characteristics of the enrolled subjects included age, sex, and flexible flatfoot conditions. Both lateral foot radiographs of the children at the time of diagnosis and at the end of treatment were taken to evaluate the effects of foot insole application in a barefoot standing position. Foot lateral radiography was used for radiographic measurement. The bilateral calcaneal pitch angle (CPA) and Meary’s angle, known as the talo first metatarsal angle (TMA), were measured in both feet. CPA is defined as the angle between the calcaneus and inferior aspect of the foot. TMA is defined as the angle between the line of the longitudinally bisected talus and the longitudinal axis of the 1^st metatarsal bone (Fig. 2). Both radiologic indices calculated through foot lateral radiography in a standing position are usually used clinically as criteria for flexible flatfoot: CPA < 15’; TMA > 3’.^{[14 (link)]} Both indices were periodically followed up within 3 to 4 months after the beginning of the foot insole prescription. The process of radiologic evaluation with adjustment of the foot insole was terminated at the point of loss of the associated symptoms, as mentioned above. All the radiographic parameters were measured by a trained physiatrist.
The foot insole was also adjusted periodically for 3 to 4 months after confirmation of the follow up radiograph. The device was custom-made using ethylene vinyl acetate with foam materials. This supported the medial longitudinal arch (Fig. 3). During the intervention, the foot insole was revised according to the height of the pad.