Excessive fluctuations in knee joint moments during early stance in sprinting are caused by digital filtering procedures
Excessive fluctuations in knee joint moments during early stance in sprinting are caused by digital filtering procedures
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DOI：
10.1016/j.gaitpost.2013.02.015
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发表时间：
2013-09-01
期刊：
影响因子：
2.4
通讯作者：
Trewartha, Grant
中科院分区：
文献类型：
--
作者：
Bezodis, Neil E.;Salo, Aki I. T.;Trewartha, Grant
逆动力学分析通常用于了解所有形式步态的运动模式。本研究的目的是确定数字滤波程序对短跑过程中计算的膝关节力矩的影响，作为数据分析过程对运动模式解释的可能影响的一个例子。数据是从三名训练有素的短跑运动员谁完成了一系列的30米短跑。将10种不同的截止频率组合应用于二维运动学和动力学输入数据，其中动力学截止频率设置为等于或高于运动学截止频率。当使用普遍采用的过滤的动力学数据的做法，具有较高的截止频率比运动学数据，夸张的波动，膝关节力矩存在后不久，接触。在极端情况下，膝关节在屈肌、伸肌和屈肌优势之间移动的时间小于33 ms，移动范围超过500 Nm。在运动的逆动力学分析期间，如果应用于运动学数据的截止频率小于真实频率内容，特别是在冲击阶段，则不匹配的截止频率将可能影响计算的关节力矩。在短跑的例子中，膝关节力矩的夸张波动似乎是数据处理的假象，而不是关节动力学的真正特征。当截止频率，从而所有输入数据的频率内容，是匹配的，接触后的波动是最小的，这样的程序建议逆动力学分析的步态。(C)2013爱思唯尔有限公司版权所有。
Inverse dynamics analyses are commonly used to understand movement patterns in all forms of gait. The aim of this study was to determine the effect of digital filtering procedures on the knee joint moments calculated during sprinting as an example of the possible influence of data analysis processes on interpretation of movement patterns. Data were obtained from three highly trained sprinters who completed a series of 30 m sprints. Ten different combinations of cut-off frequency were applied to the two-dimensional kinematic and kinetic input data with the kinetic cut-off frequency set equal to or higher than the kinematic cut-off frequency. When using the commonly adopted practice of filtering the kinetic data with a higher cut-off frequency than the kinematic data, exaggerated fluctuations in the knee joint moment existed soon after contact. In extreme cases, the knee moved between flexor, extensor and flexor dominance in less than 33 ms and through ranges exceeding 500 Nm. During an inverse dynamics analysis of locomotion, mismatched cut-off frequencies will likely affect the calculated joint moments if the cut-off frequency applied to the kinematic data is less than the true frequency content, particularly during impact phases. In the example of sprinting, exaggerated fluctuations in the knee joint moment appear to be data processing artefact rather than genuine characteristics of the joint kinetics. When the cut-off frequencies, and thus the frequency content of all input data, are matched, the fluctuations after contact are minimal and such a procedure is suggested for inverse dynamics analyses of gait. (C) 2013 Elsevier B.V. All rights reserved.