Abstract
Considering the safety in trail walking, stability is an important footwear function. As a parameter of the stability, the amplitude of body's center of mass(Wx) in the lateral direction has been focused. The purpose of this study is to clarify the influences of external factors on stability in trail walking. Through the motion analyses on even surface, it was found that averaged angle of GRF in the frontal plane during single stance, step width and toe direction were significantly related to Wx. Moreover the motion analyses on various uneven surface and with wearing various weights based on actual trail scene were also carried out. It was suggested that characteristics of unstable surface could be a parameter for considering the stability. It was also clarified that the wearing weight on his back made a great influence on Wx.
