Prediction of slips: an evaluation of utilized coefficient of friction and available slip resistance

Abstract

The purpose of this study was to investigate the relationship between measures of floor surface slip resistance and an individual's peak utilized coefficient of friction (COF_U) on the probability of a slip occurring during level walking. Video, kinematic and ground reaction force data were recorded simultaneously as subjects walked at a self-selected speed during conditions of normal and reduced floor surface slip resistance. Peak COF_U during weight acceptance was calculated and the available floor surface slip resistance was measured using the variable incidence tribometer (VIT). Separate logistic regression analyses identified that knowledge of the available slip resistance (as measured by the VIT) in combination with an individual's peak COF_U allowed for greater accuracy in classifying slip outcomes (89.5%; p = 0.004), while knowledge of only the available slip resistance reduced the accuracy of categorization to 78.9% (p = 0.021).

Keywords:

• Slip resistance
• Coefficient of friction
• Slips and falls
• Walking
• Tribometer

Acknowledgements

This work was supported, in part, by an award from the American Society of Safety Engineers and National Institute for Occupational Safety and Health to J.M.B. The authors of this paper would like to gratefully acknowledge Yi-Ju Tsai, MS, PT and Courtney D. Few, MPT for their assistance in data collection. Additionally, we would like to acknowledge John Brault, MS, PT of Macinnis Engineering Associates, Inc. and James E. Flynn, P.E. of J2 Engineering, Inc. for their technical consultations and generous support for equipment purchases.