Biomechanics of transverse axis of medial longitudinal arch of children's foot based on 3D scanning

Radiographs were made of the feet of seventy-four normal infants and children who ranged in age from six to 127 months, and various angles were measured. Means and deviations of the measurements were calculated for eleven clinically useful angles. On the anteroposterior radiographs the talocalcaneal, talus-first metatarsal, and calcaneus-fifth metatarsal angles were recorded, and on the lateral radiograph the talocalcaneal, tibiocalcaneal, tibiotalar, talus-first metatarsal, and talohorizontal angles were documented. On lateral radiographs that were made with the foot in maximum dorsiflexion, the talocalcaneal and tibiocalcaneal angles were documented and the talocalcaneal index was recorded. The mean values and the ranges of normal values changed with age. These data provide a standard for assessment of initial and residual deformity in patients who have club foot, vertical talus, metatarsus adductus, or other deformities.

There is controversy concerning the definition and measurement of the medial longitudinal arch of the foot. Various techniques are reported to assess the medial arch height, including radiographic measurements and footprint analysis, which are the most commonly used methods. Some authors define footprint analysis as unreliable for measuring the arch height. The purpose of this study was to investigate the relationship between radiologically measured angles and the arch index obtained from footprint analyses in 38 children with flexible pes planus. A positive correlation of arch index was found between lateral talo-horizontal and lateral talo-first metatarsal angles (p < 0.05). These angles have been used by some authors to describe the height of the medial longitudinal arch of the foot. This study demonstrated that footprint analysis could be used effectively for screening studies and at individual office examinations.