Abstract
Entire gait characteristics were quantized by principal component analysis (PCA) for eight children (longitudinal survey from the age of 4 years to 7) to reveal the age-related difference in children. Temporal sequence of lower-limb angle and joint moment were compressed into lower dimensional space by PCA those were then evaluated in terms of change in gait pattern and variability among different age group. As a result of PCA, both first and second principal component (PC1 and PC2) were revealed to represent the role of ankle joint. This change was reported as typical difference between children and adults in the previous research. We found out that the gait pattern continued to change linearly in the lower dimensional space, while its variability were converged into constant value with age. These results suggest that development of gait pattern and acquiring its repeatability were independent phenomena. Also, it is clear that PCA enabled us to evaluate change in entire gait pattern keeping as much information as possible that can not be achieved by kinematic index such as step length or cadence.
