Citation

Cham R, Redfern MS. Safety Sci. 2002; 40(7-8): 559-576.

Copyright

(Copyright © 2002, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

This study describes heel contact dynamics during slip events, information that must be known to develop biomechanically relevant shoe-floor coefficient of friction measurement systems. Sixteen subjects walked on a level, 5 and 10[deg] ramp with two possible contaminants (dry, oil). Foot motion was recorded at 350 Hz and compared among no-slip, slip-recovery and slip-fall events. For all trials, the foot rotated to foot-flat, even during slip and fall trials. Heel sliding patterns recorded upon and shortly after heel contact were similar for all conditions. Slip distances, sliding velocities and heel acceleration profiles varied across trials. During the fall trials, the slipping motion of the foot was found to decelerate approximately 200 to 300 ms into stance before accelerating again, eventually leading to the fall. This deceleration was believed to be an attempt by the subject to recover from the slip. Recovery attempts on inclined surfaces were less successful than on level floors. In general, the slip distance and peak forward sliding velocity associated with fall trials were greater than or equal to 10 cm and 0.8 m/s, respectively. These complex motions at the shoe-floor interface during slipping should be taken into account for improving slip resistance measurement systems.