It is known that the toe-flexors exert some power generation in ankle plantar flexion. However, there has been no paper published in which the power generation was quantified. The purpose of this paper, therefore, is to quantify the amount of contribution of the toe-flexors to the ankle plantar-flexion in normal and rapid walking using the kinetic data of three dimensional gait analysis system. In order to restrict the action of the toe-flexors, we designed special braces which can be applied to the forefeet of the examinee during walking. We performed the gait analysis in ten normal adult volunteers with and without braces, and evaluated the moment and power of toe-flexors during terminal stance and pre-swing phase of gait cycle. Gait analysis was done with the VICON 3-dimensional motion analysis system (VICON, Oxford Metrics, Oxford, England) and 2 force plates (AMTI, Advanced Mechanical Technoiogy, Newton, MA, U.S.A,). The kinetic results are as follows: