Adjustments in gait biomechanics on potentially slippery floors.
NOIRS 2000--Abstracts of the National Occupational Injury Research Symposium 2000, Pittsburgh, PA, October 17-19. Pittsburgh, PA: National Institute for Occupational Safety and Health, 2000 Oct; :48
In the workplace, unexpected slippery surfaces are often the cause of fall accidents. Findings of well-controlled gait experiments on slippery surfaces have been used to investigate slip and fall biomechanics, design "safe" foot/floor interfaces and develop slip resistance testers. However, in laboratory settings, it is quite challenging to reproduce the unexpected nature of slipping accidents. The purpose of this study was to quantify the changes in gait biomechanics when subjects anticipate a possible slippery environment and investigate whether gait returns to baseline characteristics after a contaminated trial. Foot forces and body dynamics of sixteen subjects walking on three dry surfaces (vinyl, smooth painted and rough painted plywood) of varying inclination (level, 50 and 100) were recorded at 350 Hz. Gait biomechanics were compared among baseline trials (dry conditions), anticipation dry trials with a possibility of contaminant conditions (water, soap or oil) and recovery trials (recorded after a contaminated trial). Subjects were asked to walk as naturally as possible throughout testing even though there may be a contaminant condition. A within-subject repeated measures ANOVA of the trial type (baseline, anticipation, recovery) influence and flooring effect on specific gait parameters was performed within each ramp angle condition. Anticipation trials produced peak required coefficient of friction values (RCOF) that were on average 16 to 33% significantly lower than those collected during baseline trials. During recovery trials, peak RCOFs did not return to baseline values (5-12% lower). Thus, subjects reduce slip probability on potentially contaminated floors. This reduction was achieved by adopting postural and temporal gait changes resulting in ground reaction forces decreases. In addition, as a result of these adaptations, anticipation of slippery surfaces led to significant reductions in lower extremity joint torques (particularly at the knee and hip), thus decreasing the strength requirements of walking.
Accidents; Accident-prevention; Injuries; Traumatic-injuries; Injury-prevention; Biomechanics; Posture
Conference/Symposia Proceedings; Abstract
NOIRS 2000 Abstracts of the National Occupational Injury Research Symposium 2000, Pittsburgh, PA., October 17-19, 2000
University of Pittsburgh, Department of Bioengineering, Pittsburgh, PA