Overall Kinematic Coordination Characteristic of Human Lower Limb Movement

The human lower limb movement characteristic is still a research focus, and the individual kinematic coordination characteristic of human specific lower limb movement (e.g. walking, running et al.) has been explored. However, the overall coordination characteristic of diverse human lower limb movements is rarely studied and we always ignore the fact that the coordinated movement doesn’t always coordinate all joints simultaneously. In order to investigate these issues, we firstly use principal component analysis (PCA) to study the overall kinematic coordination characteristic of human lower limb movements. The four DoF are chosen to analyze: hip flexion/extension, hip adduction/abduction, knee flexion/extension and ankle plantarflexion/dorsiflexion, and the result shows that the first two principal components contain primary human lower limb movement information, so it suggests the possibility that it exists the overall kinematic coordination. But the result of evaluating the effectiveness of the overall kinematic coordination characteristic shows that hip adduction/abduction movement and ankle plantarflexion/dorsiflexion movement can’t be reproduced well by the first two principal components. And the correlation coefficient analysis and agglomerative hierarchical cluster analysis results also show that hip adduction/abduction and ankle plantarflexion/dorsiflexion are relatively independent and the other joint movements are more correlated. So we conclude that the independent joint movement should be considered separately when studying the coordination characteristic, and correlation coefficient analysis and agglomerative hierarchical cluster analysis can give us some useful guides.