van Werkhoven Herman, Piazza Stephen J
Appalachian State University.
The Pennsylvania State University.
J Appl Biomech. 2017 Oct 1;33(5):317-322. doi: 10.1123/jab.2016-0173. Epub 2017 Sep 18.
Several recent investigations have linked running economy to heel length, with shorter heels being associated with less metabolic energy consumption. It has been hypothesized that shorter heels require larger plantar flexor muscle forces, thus increasing tendon energy storage and reducing metabolic cost. The goal of this study was to investigate this possible mechanism for metabolic cost reduction. Fifteen male subjects ran at 16 km⋅h on a treadmill and subsequently on a force-plate instrumented runway. Measurements of oxygen consumption, kinematics, and ground reaction forces were collected. Correlational analyses were performed between oxygen consumption and anthropometric and kinetic variables associated with the ankle and foot. Correlations were also computed between kinetic variables (peak joint moment and peak tendon force) and heel length. Estimated peak Achilles tendon force normalized to body weight was found to be strongly correlated with heel length normalized to body height (r = -.751, p = .003). Neither heel length nor any other measured or calculated variable were correlated with oxygen consumption, however. Subjects with shorter heels experienced larger Achilles tendon forces, but these forces were not associated with reduced metabolic cost. No other anthropometric and kinetic variables considered explained the variance in metabolic cost across individuals.
最近的几项研究将跑步经济性与足跟长度联系起来，足跟较短与较低的代谢能量消耗相关。据推测，较短的足跟需要更大的跖屈肌力量，从而增加肌腱能量储存并降低代谢成本。本研究的目的是探究这种降低代谢成本的可能机制。15名男性受试者在跑步机上以16 km·h的速度跑步，随后在装有测力板的跑道上跑步。收集了氧气消耗、运动学和地面反作用力的测量数据。对氧气消耗与与脚踝和足部相关的人体测量学和动力学变量进行了相关性分析。还计算了动力学变量（峰值关节力矩和峰值肌腱力）与足跟长度之间的相关性。发现以体重归一化的估计跟腱峰值力与以身高归一化的足跟长度密切相关（r = -0.751，p = 0.003）。然而，足跟长度以及任何其他测量或计算的变量均与氧气消耗无关。足跟较短的受试者跟腱力较大，但这些力与代谢成本降低无关。所考虑的其他人体测量学和动力学变量均无法解释个体间代谢成本的差异。
