Hornestam Joana F, Souza Thales R, Arantes Paula, Ocarino Juliana, Silva Paula L
J Am Podiatr Med Assoc. 2016 Nov;106(6):419-426. doi: 10.7547/15-120.
The relation between walking speed and foot kinematics during gait is not well established, and neither is it clear whether this relation is modified in the presence of factors expected to increase pronation (eg, abnormal foot alignment). Understanding how foot kinematics is affected by walking speed under varying conditions could contribute to our understanding of stresses to the musculoskeletal system during walking. We evaluated the effect of walking speed on foot kinematics in the frontal plane during gait and determined whether this effect is modified by using medially inclined insoles that force the foot into increased pronation.
Twenty-six healthy young adults were assessed while walking on a treadmill wearing flat insoles and wearing medially inclined insoles. Foot kinematics in the frontal plane was measured with a three-dimensional motion analysis system. Data were analyzed during the stance phase of gait.
There was no main effect of speed on average calcaneal position. However, there was a significant insole type × walking speed interaction effect. In the flat insole condition, increased walking speed was associated with a less inverted average calcaneal position (or greater magnitudes of eversion), whereas in the inclined insole condition, higher speeds were associated with a less everted average calcaneal position (or increased magnitudes of inversion).
The magnitude of foot eversion increases at faster gait speeds under typical conditions. In the presence of factors that induce excessive pronation, however, this effect is reversed. Results suggest that individuals use greater active control of foot motion at faster speeds in the presence of excessive pronation to improve push-off efficiency. Potential clinical consequences of this functional strategy are discussed.
步态期间步行速度与足部运动学之间的关系尚未完全明确，而且在存在预期会增加旋前的因素（如足部排列异常）时这种关系是否会改变也不清楚。了解在不同条件下步行速度如何影响足部运动学，有助于我们理解步行过程中肌肉骨骼系统所承受的压力。我们评估了步行速度对步态期间额状面足部运动学的影响，并确定使用内侧倾斜鞋垫迫使足部增加旋前是否会改变这种影响。
对26名健康的年轻成年人在跑步机上行走时进行评估，分别穿着平底鞋垫和内侧倾斜鞋垫。使用三维运动分析系统测量额状面的足部运动学。在步态的站立期对数据进行分析。
速度对平均跟骨位置没有主要影响。然而，存在显著的鞋垫类型×步行速度交互作用效应。在平底鞋垫条件下，步行速度增加与平均跟骨位置较少内翻（或更大程度的外翻）相关，而在倾斜鞋垫条件下，较高速度与平均跟骨位置较少外翻（或内翻程度增加）相关。
在典型条件下，更快的步态速度会使足部外翻程度增加。然而，在存在导致过度旋前的因素时，这种影响会逆转。结果表明，在存在过度旋前的情况下，个体在更快速度时会对足部运动进行更大程度的主动控制，以提高蹬离效率。讨论了这种功能策略可能产生的临床后果。
