Evaluating the repeatability of friction coefficient measurements and tactile perceptions in skin-textile interactions across body regions

Measuring the friction between human skin and textiles is essential to preventing skin-related health problems and wearer discomfort. This study sought to evaluate the repeatability of friction coefficient measurements and tactile perceptions at various human body regions, using a recently developed portable friction measuring device. Using the device, a cotton textile was applied to six test locations. The friction coefficient and tactile perceptions were taken three times, at each test site. The repeatability of friction coefficient was excellent with ICC of 0.91 ± 0.05 for static and 0.91 ± 0.06 for dynamic friction coefficient, and tactile perception showed good to excellent repeatability. The friction coefficient and tactile perception significantly differed across the body regions (p = 0.008 and p = 0.003, respectively). The chest showed the highest static friction coefficient with 0.90 ± 0.19 and dynamic friction coefficient with 0.79 ± 0.20, whereas the dorsal forearm with static 0.31 ± 0.07 and dynamic 0.25 ± 0.05 was the lowest. The ratings of tactile perceptions were independent of friction coefficient when the changes in the coefficient of friction are induced by regional difference, and/or the range of the coefficient of friction value are small. Moreover, skin temperature and friction coefficient correlated positively, while cutaneous hydration and friction coefficient did not.