Use of backward slip to predict falls in friction test protocols

In standard friction test protocols, backward slip in the takeoff phase is not considered because it is not believed to offer additional information about the prediction of slips and falls. A possible reason for the exclusion was because conventional slips and falls studies have used walking surface and shoe combinations that have a relatively high coefficient of friction. However, a normal gait pattern cannot be maintained when the frictional characteristics of a floor are low, and therefore there may be other measures of gait performance that are better predictors of loss of balance in extremely low frictional conditions. Therefore, a new approach, namely "backward slip" in the takeoff phase, was used to predict loss of balance when the frictional characteristics of a floor are low. As a result, dangerous falls initiated by backward slip were observed in this study, in contrast to the absence of backward slips in conventional studies. In addition, the conditional probability and logistic regression results showed backward slip in the takeoff phase could be an alternative measure in predicting dangerous falls because no significant difference was found between backward slip and forward slip in the prediction of dangerous falls.