Slip Resistance Needs of the Mobility Disabled During Level and Grade Walking

Abstract

Slip resistance needs were compared between mobility disabled and able-bodied individuals. Subjects walked across a level piezoelectric force plate at slow and fast speeds, and the ratio of the total shear force to the normal force was used as the required coefficient of friction (μr) Near touchdown,μr was found to be significantly greater (p < 0.05 for all significance values) for the mobility disabled (0.64 ± 0.19) than for the able-bodied (0.31 ± 0.07), regardless of the speed of walking. In contrast, slip resistance needs for these two groups were not different near push-off (disabled and able-bodied were each 0.41 ±0.17), although for both groups walking fast required significantly greater slip resistance (0.48 ± 0.19) than walking slow (0.34 ± 0.11). Required coefficient of friction was also calculated as disabled subjects walked up and down a ramp of 1:12 grade. At touchdown, no significant differences among the mean μr values were found for level, uphill, and downhill walking at slow or fast speeds. At push-off, slow-speed walking uphill required significantly greater slip resistance (0.46 ± 0.20) than level (0.34 ± 0.14) or downhill (0.34 ± 0.17) walking. No difference was found among the three grades for the fast speed. It was concluded that the mobility disabled do require greater slip resistance than the able-bodied, and that this puts them at increased risk for falling.

Human-centred approaches in slipperiness measurement

“…The double support period, expressed as a percentage of the total support period, lengthened and the single support period shortened significantly as the load increased. Buczek et al (1990) emphasized that the slip resistance needs for mobility disabled may be greater than for able-bodied persons. Their study indicated that the required coefficient of friction near touch-down for the unaffected side of the mobility disabled person was significantly higher (average 0.64) than for the able-bodied (average 0.31) regardless of the speed (slow or fast) of walking, whereas no difference was observed for the push-off phase.…”

Effects of Flooring and Hemi Body on Ground Reaction Forces and Coefficient of Friction in Stroke Gait

“…The new pattern that emerges in such a situation can be affected by many factors, for instance, the gender [1] and/or some pathological condition [2][3][4][5][6]. However, with few exceptions [7], most of the stroke gait studies have focused on measuring the walk in rehabilitation environments which may be less complex than the environment typically encountered in the home setting.…”

“…Previous studies have shown that peak RCOF varies with age [1], gender [1], limb dominancy [11,12] and the presence of a disability [2][3][4][5][6]. Those with a disability would appear to be at potentially greater risk owing to the largest changes in gait characteristics and GRFs.…”

“…Buczek et al [2] found that persons with a disability (amputations, broken leg, osteotomy of the fifth metatarsal) had higher peak RCOF during level walking when compared to persons without a disability. Durá et al [4] also examined a diverse sample including amputees, Parkinson's disease, and stroke individuals.…”

“…Examination of the collective results of these studies [2,3], suggests that only one class of individuals with walking impairments (i.e., those with prosthetics/amputations) is likely to require higher levels of slip resistance than do normal walkers. Moreover, these studies [2][3][4] did not systematically examine a unique medical condition (i.e., stroke); different medical conditions analyzed at the same time can have higher data variability and enshroud some results.…”