Predicting the Probability of Slip in Gait: Ramp Walking

When predicting the probability of a slip in gait, previous researchers have only considered level gait. There are no known attempts to apply probabilistic theory to predict the probability of a slip on ramped surfaces, even though there is a larger friction requirement for ramp gait compared to level gait. It is shown that when predicting the likelihood of a slip in ramp gait, the maximum value of the required coefficient of friction (RCOF) over the entire step must be considered. This is in contrast to level gait, where only one of the local maxima of the RCOF time profile is considered. This study predicts the probability of slip in gait for both up-slope gait and down-slope gait and discusses the major differences between the two. In general, it is found that up-slope gait has a higher potential for slip compared to down-slope gait and level gait.