University of Calgary, Calgary, Alberta, Canada.
Hum Factors. 2012 Feb;54(1):5-13. doi: 10.1177/0018720811427902.
The objective of this study is to examine ground kinetics early in stance while walking on a contaminated surface and assess the potential of kinetics to quantify risk of slipping.
Prior studies of slipping have dismissed early ground kinetic data,and therefore no prior literature has been able to assess the viability of using these data to quantify slip potential.
A total of 11 healthy male participants volunteered to walk over a force plate that was at random times contaminated with soap.Ground kinetics were measured by the force plate (2400 Hz), and heel displacement was quantified using high-speed video cameras (240 Hz) and retro-reflective markers.
The results indicated a significant reduction in shear force as early as 0.42 ms after heelstrike for contaminated trials, whereas for utilized coefficient of friction, a significant reduction was not seen until 11.34 ms. Heel displacements considered "safe" in the literature (< 30 mm) demonstrated proportionally different thresholds for shear force and utilized coefficient of friction.
The authors suggest that shear force in early stance shows more promise in quantifying slip potential as compared to utilized coefficient of friction given that (a) significant differences are seen earlier in shear than utilized coefficient of friction and (b) the threshold for utilized coefficient of friction, over which heel displacement stabilized to a"safe" value, exceeded values for utilized coefficient of friction that have been recommended as "safe".
These results have wide implications for standards related to the design and testing of interventions to prevent injuries because of slipping.
本研究旨在考察污染表面行走时早期的地面动力学，并评估动力学量化滑倒风险的潜力。
先前的滑倒研究忽略了早期的地面动力学数据，因此，没有先前的文献能够评估使用这些数据来量化滑倒潜力的可行性。
共有 11 名健康男性志愿者自愿在随机时间被肥皂污染的力板上行走。地面动力学通过力板（2400Hz）进行测量，脚跟位移通过高速摄像机（240Hz）和反光标记进行量化。
结果表明，与污染试验相比，脚跟触地后 0.42 毫秒时剪切力显著降低，而对于利用摩擦系数，直到 11.34 毫秒才出现显著降低。文献中认为“安全”的脚跟位移（<30mm）表现出剪切力和利用摩擦系数的比例不同的阈值。
作者认为，与利用摩擦系数相比，早期站立时的剪切力在量化滑倒潜力方面更有前景，因为（a）剪切力的显著差异出现得比利用摩擦系数更早，（b）脚跟位移稳定到“安全”值的利用摩擦系数阈值超过了被推荐为“安全”的利用摩擦系数值。
这些结果对与设计和测试防止因滑倒而受伤的干预措施相关的标准具有广泛的影响。
