Proper Selection of Foot Insole for Slippers

In the present work, the friction coefficient (μ) between bare foot and foot wearingsocks sliding on insoles to facilitate the proper selection of the insole materials. Inorder to avoid car accidents, it is necessary that the value of friction coefficientbetween the surfaces of foot skin and insoles should be enough high to prevent footslip on the braking pedal pad. When the foot slides on the insole to a certain distancefor people wearing slipper, the risk of car accident is arising. Two types of naturalleather and four types of polymeric insoles, used in manufacturing of shoes andslippers, were tested to determine friction coefficient between bare foot and the testedinsolesThe experiments revealed that μ decreased with increasing the normal load displayed.The sliding of bare foot against natural leather (I, II) insole showed relatively highervalues than foot wearing sock. In addition, polymeric insole (III) experiencedrelatively higher μ compared to that observed for the natural leather. While insole(IV), bare foot displayed higher μ than foot wearing sock. As for insoles (V and VI)of rougher surfaces, significant increase in μ was observed compared to the insoles ofsmooth surfaces, where the values of μ can be considered quite good to guarantee tolimit slip. Finally, it is proposed to roughen the insole surface to increase μ values.