Foot progression angle and ankle joint complex in preschool children.

OBJECTIVE The influence of foot progression angle on the ankle joint and the effects on gait patterns and mechanisms in skeletally normal preschool children was investigated. DESIGN Kinematics and kinetics of the ankle joint were analyzed for preschool children who were skeletally normal but walked with different foot progression angle. BACKGROUND The most frequent reasons for preschool children to be brought to a paediatric orthopaedic clinic are toe-in and toe-out. Without understanding the biological and biomechanical implications, treatment for these problems can be very confusing. METHODS Gait analysis was performed in 86 skeletally normal preschool children. Children were grouped according to their foot progression angles. Analysis of the kinematics and kinetics of the ankle joint was intended to elucidate the gait mechanism. RESULTS Children with different foot progression angles had distinctive patterns of spatio-temporal parameters, ground reaction force, joint angle, moment, power, and mechanical work of the ankle joints. The differences were organized and explained as different walking patterns and tactics. CONCLUSIONS Skeletally normal preschool children with excessive toe-in or toe-out foot progression angles are not necessarily in some diseased status. They were instead related to different walking patterns. Aggressive treatment for these problems is not recommended.RelevanceThese results suggest that toe-in and toe-out are related to walking speed which has distinct influences on the kinematics and kinetics of the ankle joint. Though the observed problems were seemingly only in the transverse plane, they are in fact three-dimensional and have a mutually close relationship. The findings could be linked to the promptness of muscle response and the habits of walking in preschool children. Better understanding of possible mechanisms will help parents and paediatricians decide on the most appropriate treatment for these children.