Biomechanical characteristics of slipping during unconstrained walking, turning, gait initiation and termination

Abstract

Slipping biomechanics was investigated on both non-contaminated and oil-contaminated surfaces during unconstrained straight-line walking (‘walking’), turning, gait initiation and termination. In walking, backward slipping was more frequent, whereas forward slipping was more frequent when turning. Stopping and gait initiation engendered only forward and backward slipping, respectively. Based on slip distance and sliding velocity, severity of forward slipping was least in walking than for the other gait tasks, whereas the tasks had similar effects on backward slipping. Relative to the dry surface, heel and foot contact angles reduced and heel contact (HC) velocity increased for all gait tasks on the contaminated surface. Ground reaction forces were generally lower on the contaminated surface, suggesting kinetic adaptation immediately following HC. Required coefficient of friction (RCoF) did not correlate with slip distance suggesting that RCoF may not be a useful kinetic parameter for assessing slipping risk on contaminated surfaces.

Practitioner Summary: Slipping is hazardous in everyday locomotion and occupational settings. This study investigated foot control kinematics and kinetics across various gait tasks on both a non-contaminated and an oil-contaminated walking surface. Turning, gait termination and gait initiation were associated with a greater risk of slip-related falls than unconstrained walking.

Keywords:

• slip biomechanics
• gait initiation and termination
• turning
• ground reaction force
• oil contaminant

Acknowledgements

This research was undertaken with financial support from ASICS (Asia-Pacific), and we wish to thank Mark Doherty and Claire Thomas for their invaluable contributions to the project. This work was supported in part by the Australian Government Collaborative Research Networks (CRN) program. We also thank Richard Bowman (Intertile Research Pty Ltd.) for his assistance with coefficient of friction testing.