Early emergence of temporal co-ordination of lower limb segments elevation angles in human locomotion

Abstract

We analysed the co-ordination of the elevation angles of the thigh ( α t ), shank ( α s ) and foot ( α f ) during walking in 19 adults and 21 children (aged 11–144 months), including the very first unsupported steps in four. Cross-correlation functions ( CCF) maturation of pairs of elevation angles was quantified by a global error parameter ( Et ( CCF) ) reflecting the difference between particular CCF value of toddlers and mean adult value ( Ea ( CCF) ). During the very first step, Et ( CCF) could be five times higher than Ea ( CCF) . With walking experience, Et ( CCF) for both α t - α s and α s - α f pairs evolved following a biexponential profile, with a fast time constant below 6 months. Adult-like CCF parameters were reached earlier for α s - α f than α t - α s , indicating disto-proximal maturation of the temporal co-ordination of the lower limb segments in human locomotion.