Influence of Walking Direction on the Intra-Limb Coordination of Healthy Children Aged between Three and Six

The aim of this study was first to compare the differences of coordination between forward walking (FW) and reversed backward walking (RevBW) in 40 healthy children aged between three and six; and then to explore interaction effects of age and direction of motion on intra-limb coordination. Kinematics of FW and RevBW of those subjects were measured by Coda motion system. Based on the Euler angle (EA) and angle velocity in knee (OAB), ankle (ABD) and metatarsophalangeal joint (MTH)(BDF), continuous relative phase (CRP) between knee-ankle (θCRP(K-A)) and ankle-metatarsophalangeal (θCRP(A-M)) were calculated. Coefficient of variance between FW and RevBW in each EA and CRP variable were figured out. Statistical model of independent T test and paired T test, as well as univariate analysis were applied with significant level of 0.05 and confidence interval of 95%. Our results show that RevBW significantly increased the amplitude of knee, ankle and MTH joint; while majority of inter-age CoV-EA variables were found less prominent, with exception of CoV-EA (OAB) between ages of five to six. Amplitude-EA variables were recorded with significant differences between FW and RevBW in each age group. In terms of interaction effects, only walking direction showed significant impact on the variables of amplitude-EA. Overall, although BW increased amplitude of motion in knee, ankle and MTH joint, children aged between three and six have already achieved a mechanism that central nervous system could switch their gait control freely.