“…The researcher noted down additional variables for each subject and six variables were measured for each measurement condition: the static and dynamic coefficient of friction, skin hydration, skin temperature, ambient temperature and air humidity. In the literature, the type of material of the contact (Adams et al, 2007;Asserin et al, 2000;Bertaux et al, 2010;Bobjer et al, 1993;Derler et al, 2012;Elleuch et al, 2007;Gerhardt et al, 2008a;Lewis et al, 2000;Sivamani et al, 2003;Tomlinson et al, 2011;Zhang and Mak, 1999), the normal load between this material and the skin (Adams et al, 2007;Bobjer et al, 1993;El-Shimi, 1977;Elleuch et al, 2007;Gerhardt et al, 2008a;Gitis and Sivamani, 2004;Koudine et al, 2000;Skedung et al, 2011;Zhang and Mak, 1999), and the relative velocity between the materials (Bobjer et al, 1993;Bullinger et al, 1979;Elleuch et al, 2007;Gerhardt et al, 2008a;Zhang and Mak, 1999) are considered to be important variables in the friction measured at the human skin. In this paper, the contact material, the normal load and the relative velocity are maintained constant in order to decrease the influence of these variables and consequently to limit the number of variables in the statistical analyses.…”