ランニング・シューズの力学特性の計測と評価法 ( スポーツ工学)

Running shoe sole has an important role to absorb the external impact forces that transmitted from the running surface. Especially, tile impact force occurred on the runner's heel is about 3 times of the runner's weight. Therefore, the purpose of this paper is to show the method of measurement and evaluation for the mechanical characteristics of shoe sole. The impact device used in the trials, is made by considering the collision conditions between human heel and the running surface. It means the maximum impact force is about 2 kN, the impact velocity is 1 m/s and the duration time of load is about 20 to 40 ms. To satisfy all the conditions, we proposed a drop-weight type testing system with an accurate measuring devices. A variety of commercial running shoes were chosen randomly for the trials, to check up the validity of the testing system. From the measurements, the mechanical properties of each shoe, including the maximum impact force, maximum deformation, rate of energy absorption, average Young's modulus, etc, are extracted to evaluate the individual cushioning characteristics. At the same time, the human sensory evaluation of each shoe was done to compare with the mechanical measurements. As the result, by observing the similar tendencies of these two evaluations that we have obtained, it is obviously that the mechanical measurements have definite correlations with human senses.