Walking–sliding experimental analysis of frictional characteristics socked feet

Simulation experiments and in-vivo experiments were widely employed for investigating sock-skin frictional characteristics. The simulation experiments usually was a type of sliding experiment which described the relative slip between fabric and artificial skin. The in-vivo approaches typically involved subjects adopting a variety of postures and friction between their clothing and the skin was estimated. However, simulation and in-vivo experiments were reported only separately. The connection between the two types of experiments was scarcely reported. To reveal the connection, we synchronously carried out two interrelated experiments, a natural walking experiment and sliding experiment, using the same sock fabric. In the natural walking experiment, the subject wearing socks walked on the force platform. Then the soles of these socks were cut out and were used in the soles-artificial skin sliding experiment. The coefficients of friction in the two types of experiments reflected some correlative frictional characteristics. We found the effect of the walking speed or sliding speed on the friction coefficient was not significant. While, water content increased the friction coefficient in the two experiment. Additionally, the friction in the coronal direction was smaller than that in the sagittal direction during walking. Through our efforts, we hope to bridge the simulation and in-vivo experiments and elucidate the frictional characteristics between the sock and insole.