Biomechanics and performance of slip resistant soles for personal and work footwear

福尔斯是加拿大意外伤害的主要原因，随着年龄的增长呈指数级增长，在老年妇女中更为普遍。其中近三分之一是由于滑倒、绊倒和绊倒或因冰雪而福尔斯在同一水平线上。因此，加拿大鞋类制造商不断努力开发新的防滑鞋，但现有的加拿大和国际标准评估鞋类防滑最近受到质疑。 影响鞋底防滑性的因素很多，包括复合材料的性能和鞋底踏面形状、宽度或深度等内在参数，但最有可能驱动鞋底防滑性的基本力学原理仍然被误解。外部参数也可能影响鞋类滑动，例如流体或颗粒的存在、地面特性或穿着者的步态模式，但是很少有研究具有足够大的滑动来平衡恢复并且避免跌倒并不总是可能的。 本研究项目的总体目标是更好地了解导致鞋类滑动的原因，以便通过三种方式减少滑倒伤害：a）通过调查固有鞋底设计参数如何影响鞋类-地面界面处的可用摩擦系数，无论是在滑动的第一毫秒还是在滑动期间; B）通过在人类步态实验研究期间测量外部滑动参数对所需摩擦系数的影响，其中足够大的滑动并不总是可能避免跌倒;和c）依靠从a和B获得的新见解，我们将提出新的方法来评估鞋的防滑性，以用于认证目的，并为加拿大所有年龄段的女性和男性提出新的鞋底设计。具体来说，在本研究项目结束时，我们希望将鞋类在湿陶瓷和干冰上的摩擦系数提高10-20%。此外，我们希望消除男女鞋款之间的防滑性能差异。

Falls are the leading causes of unintentional injuries in Canada, increase exponentially with age and are more prevalent in older women. Nearly one third of them are falls on the same level from slipping, tripping and stumbling or falls due to ice and snow. Canadian footwear manufacturers thus constantly strive to develop new slip resistant footwear, but existing Canadian and international standards for evaluating footwear slip resistance have been recently questioned. Many factors can influence sole slip resistance, including intrinsic parameters such as compound material properties and sole tread shape, width or depth, but the basic mechanical principles most likely driving sole slip resistance are still misunderstood. Extrinsic parameters may also affect footwear slipping, such as the presence of fluids or particles, ground characteristics, or gait patterns of the wearer, but there are few studies with sufficiently large slips that balance recovery and avoiding a fall is not always possible. The overall goal of this research project is to get a better understanding of what leads to footwear slipping, so as to contribute to the reduction of slip injuries, in three ways: a) by investigating how intrinsic sole design parameters affect the available coefficient of friction at the footwear-ground interface, both in the first milliseconds of a slip and during slipping; b) by measuring the effect of extrinsic slip parameters on the required coefficient of friction during human gait experimental studies, with sufficiently large slips that avoiding a fall is not always possible; and c) by relying on new insights acquired from a and b, we will suggest new ways to evaluate footwear slip resistance for certification purposes and new sole designs for Canadian women and men of all ages. Specifically, by the end of this research project, we want to improve the coefficient of friction of footwear by 10-20% on wet ceramic and dry ice. Moreover, we hope to eliminate slip resistance performance differences between women and men footwear models.