The role of center of mass kinematics in predicting peak utilized coefficient of friction during walking

Slips frequently occur when the friction required between the foot and floor exceeds available surface slip resistance. To date, the ability to identify variables that predict an individual's friction needs during walking, or utilized coefficient of friction (COF_U), remains limited. Understanding COF_U in the context of pedestrian/walkway accidents is important as individuals who demonstrate higher COF_U are at a greater risk of slipping. This study determined if whole body center of mass (CM) kinematics were predictive of peak COF_U during walking. Ground reaction forces and kinematic data were recorded simultaneously as subjects walked. Stepwise regression analysis determined that the combination of the subject's CM-to-center-of-pressure angle and CM anterior (i.e., forward) velocity predicted 62% of the variance in peak COF_U during weight acceptance (p < 0.001). The identified relationships between CM kinematics and peak COF_U provide insight into how gait and individual anthropometric characteristics may increase risk for slip initiation.