SLIP RESISTANCE OF THE SHOE FLOOR INTERFACE UNDER BIOMECHANICALLY-RELEVANT CONDITIONS

Slip resistance measurements are used by industry, shoe/floor manufacturers, and the legal profession as a criterion for determining slip potentials of various environments. Whilst static coefficients of friction (COF) of a shoe-floor interface have been used traditionally, dynamic COF (DCOF) measures have been shown to be more relevant to the biomechanics of slips and falls. Recently, new devices have become available that better incorporate the biomechanics of foot movement into DCOF measurement. The purpose of this study was to investigate the effects of environmental and biomechanical factors of the shoe-floor interface on DCOF measures using a new slip resistance testing device. The environmental factors chosen were shoe material, floor type, and contaminant. The biomechanical factors were heel velocity, vertical force, and shoe angle. The results showed that of the biomechanical factors, heel velocity had largest effects on the DCOF. However, contaminant condition was an important interaction. Increases in velocity created increases in DCOF for dry and wet conditions, but decreases in COF for oily conditions. Vertical force and shoe angle were found to have either no effect (p<0.05) or only minor effects. Of the environmental factors, contaminant condition was the most influential factor. Shoe type had a large effect both as a primary variable and as an interaction with contaminant condition. These results indicate that choice of testing parameters is important when conducting slip resistance testing and that these parameters should be relevant biomechanically. A discussion of how these results are useful in workplace design to prevent slips and falls is also presented.