Kinesiological characteristics of ankle joint and rearfoot motion.

Kinesiological analysis of tarsal bones provides better understanding of foot disorders, especially in early childhood, when radiography is hindered by delayed ossification of foot bones. Children begin to walk in the age of 9-15 months, with rearfoot inversion only in initial contact phase, while inversion during terminal stance phase is delayed. Adult walking pattern is usually established at six years of age. Talocrural joint axis medial slope shifts during movements depending on the what part of talus comes in contact with maleolli. As a result, plantar flexion includes valgus, and dorsal flexion includes varus inclination. Subtalar joint axis highly varies among individuals: from 200-680 in sagittal and from 40-470 in frontal plane, with impact on coupled lower leg rotation movements around longitudinal axis. Midtarsal joint has two axes, and their position control the rigidity of forefoot and midfoot kinetic chain. Movement planes of tarsal bones strongly influence walking pattern as well as secure foot development.