Relating Friction on the Human Skin to the Hydration and Temperature of the Skin

The human skin is constantly in interaction with materials and products. Therefore, skin friction is relevant to all people. In the literature, the frictional properties of the skin have been linked to a large variety of variables, like age, gender and hydration. The present study compares the data of 450 skin friction measurements with the skin hydration and skin temperature on four locations on the body, measured with four materials: stainless steel (SST), aluminum (Al), PE and PTFE. The median skin temperature was 32.1 A degrees C and the median skin hydration was 25.5 AU, as measured with a Corneometer. The median coefficient of friction was 0.52 for the static coefficient of friction and 0.36 for the dynamic coefficient of friction. There was a linear relationship between those two types of coefficient of friction. The coefficient of friction was highest for SST and lowest for PTFE. The frictional properties depend on the skin hydration and skin temperature. Gender differences were found for both skin hydration and coefficient of friction. Most of the variation in the coefficients of friction could be explained by the differences in hydration.