Self-Organization of Lower Limb Motion in Human Locomotion
Takashi Yokoi*, Akihiko Takahashi*, Keigo Ohyama Byun**
*National Institute of Bioscience and Human Technology, Higashi 1-1, Tsukuba, Ibaraki 305, Japan
**University of Tsukuba, Tsukuba, Ibaraki 305, Japan
This project was undertaken to demonstrate the modal bifurcation displayed in human locomotion and the nature of motional self-organization found in the lower limb joints via the continuously measured walking and running of subjects on a treadmill for five minutes. The knowledge obtained from this study is as follows: (1) The self-organizational patterns of leg motion differ between walking and running. (2) This pattern shift is achieved based on the joint angular relationship and the change in the dynamical systems controlling the flexion and extension of the ankle and hip joints. The motion pattern is entrained to a final state immediately following the changeover. (3) Chaotic movements were observed in joint-angle time-series data, but the wide variance exhibited in Lyapunov exponent is dependent on the evolution time value set in the calculation. (4) If chaos occur in the lower limb motion of locomotion, we safely achieve locomotion in our everyday life by positively adopting the body and environmental conditions through the utilization of the selfsame chaos.