The evaluation of shoe stability based on the measurement of three-dimensional foot joints movements

Abstract

In this study the three-dimensional motions of foot joints during running were precisely measured by a motion capture system and it is attempted to extract a more reliable index to be able to evaluate the stability of the calcaneus or shoe. It is discussed how the three dimensional motions of foot joints correlate with the stability of the running shoe and also to clarify the relationship between the foot joint motions and the hardness of surface. The joint coordinate system based on the foot anatomy is defined and various three dimensional angles are determined as candidates for an index to evaluate the stability of the shoe. As an application, foot joints motions during running on the surfaces with different hardness were measured and the stability is investigated on the basis of the differences of the measured motions. As a result, the maximum eversion will be a potential index to evaluate the stability of calcaneus, which will be equivalent to the stability of shoe or surface. On the other hand the maximum plantar flexion angle does not reflect the difference of the hardness of surface very well. Thus the maximum plantar flexion angle is not so suitable as has been often accepted as an index to represent the stability of the calcaneus or shoe. ABSTRACT FROM AUTHOR