J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida , Gainesville, FL, USA.
Department of Kinesiology and Nutrition Sciences, University of Nevada , Las Vegas, NV, USA.
J Sports Sci. 2020 Aug;38(16):1869-1876. doi: 10.1080/02640414.2020.1761767. Epub 2020 May 7.
Loading rates have been linked to running injuries, revealing persistent impact features that change direction among three-dimensional axes in different footwear and footstrike patterns. Extracting peak loads from ground reaction forces, however, can neglect the time-varying loading patterns experienced by the runner in each footfall. Following footwear and footstrike manipulations during laboratory-based overground running, we examined three-dimensional loading rate-time features in each direction (X, Y, Z) using principal component analysis. Twenty participants (9 M, 11 F, age: 25.3 ± 3.6 y) were analysed during 14 running trials in each of two footwear (cushioned and minimalist) and three footstrike conditions (forefoot, midfoot, rearfoot). Two principal components (PC) captured the primary loading rate-time features (PC1: 42.5% and PC2: 22.8% explained variance) and revealed interaction among axes, footwear, and footstrike conditions (PC1: = 5.6, = 0.007, = 0.23; PC2: = 62.3, < 0.001, = 0.77). Rearfoot running in cushioned footwear attenuated impact loads in the vertical direction, and forefoot running in minimalist footwear attenuated impact loads in the anterior-posterior and medial-lateral directions relative to forefoot running in cushioned shoes. Loading patterns depend on footwear and footstrike interactions, which require shoes that match the runner's footstrike pattern.
加载率与跑步损伤有关，揭示了在不同鞋类和足触地模式下在三维轴之间改变方向的持续冲击特征。然而，从地面反作用力中提取峰值负载可能会忽略跑步者在每次足落地时经历的时变负载模式。在基于实验室的地面跑步中进行鞋类和足触地操作后，我们使用主成分分析研究了每个方向（X、Y、Z）的三维加载率-时间特征。20 名参与者（9 名男性，11 名女性，年龄：25.3±3.6 岁）在两种鞋类（缓冲型和极简型）和三种足触地条件（前足、中足、后足）的 14 次跑步试验中分别进行了分析。两个主成分（PC）捕获了主要的加载率-时间特征（PC1：42.5%，PC2：22.8%解释方差），并揭示了轴、鞋类和足触地条件之间的相互作用（PC1： = 5.6， = 0.007， = 0.23；PC2： = 62.3， < 0.001， = 0.77）。缓冲鞋类的后足跑步会减轻垂直方向的冲击载荷，而极简鞋类的前足跑步会减轻前-后和内-外侧方向的冲击载荷，相对于前足在缓冲鞋中的跑步。加载模式取决于鞋类和足触地的相互作用，这需要与跑步者的足触地模式相匹配的鞋子。
