PDF(Pubmed)
Abstract：
Background: Fatigue is a process that results in a decreased ability to produce force, and which could eventually affect performance and increase the risk of injury. Force variability analysis has been proposed to describe the level of fatigue with the purpose of detecting the development of fatigue. Variability is credited to play a functional and adaptive role through which the components of a system self-organize to solve a motor problem. Non-linear tools have been applied to analyze the variability of physiological signals, revealing that the structure of motor fluctuations provides relevant information about the functional role of variability. It has been suggested that the presence of lower complexity in the variability structure could reveal a less functional and adaptative state (e.g., ageing or illness). In the last years, an increased number of studies have applied these techniques to force variability analysis in relation to fatigue. Objective: To provide an overview of the current knowledge on the use of non-linear tools on force variability as a fatigue index. Methods: Following PRISMA guidelines, a systematic search of SPORTDiscus, Scopus, Web of Science and PubMed was carried out. Studies included were: a) original studies that analyzed the effect of fatigue on humans during an action focused on force production; b) published studies with their title and abstract in English; c) studies that applied non-linear tools on a signal directly related to force production. Results: Twenty-five studies were included in this review. The relationship between fatigue and the complexity of force variability, the type of action and relative intensity, the nature of the signal and the non-linear tools used, and the methods of data acquisition and processing were identified. Conclusion: The articles reviewed suggest that fatigue leads to a decrease in complexity mostly in isometric contractions, but this is not as clear in dynamic contractions. This fatigue-induced loss of complexity seems to be a result of changes in the nervous system at the central level, albeit triggered by peripheral mechanisms. It should be noted that non-linear tools are affected by the relative intensity of contraction, non-stationarity, and the acquisition and treatment of the signal.
摘要：
背景：疲劳是一个过程，导致产生力的能力下降，这最终可能会影响性能并增加受伤的风险。已提出力变异性分析来描述疲劳水平，以检测疲劳的发展。可变性被认为起着功能性和适应性的作用，系统的组件通过该作用自组织来解决运动问题。非线性工具已用于分析生理信号的变异性，揭示了运动波动的结构提供了有关变异性的功能作用的相关信息。有人提出，可变性结构中较低复杂性的存在可能会揭示出功能和适应性状态较差（例如，衰老或疾病)。在过去的几年里，越来越多的研究将这些技术应用于与疲劳相关的力变异性分析。目的：提供有关使用非线性工具对力变异性作为疲劳指标的当前知识的概述。方法：遵循PRISMA指南，对SPORTDiscus的系统搜索，Scopus,进行了WebofScience和PubMed。研究包括：a）原始研究，分析了疲劳在作用力产生过程中对人类的影响；b）发表了标题和英文摘要的研究；c）在信号上应用非线性工具的研究与力的产生直接相关。结果：25项研究纳入本综述。疲劳与力变异性复杂性之间的关系，动作的类型和相对强度，信号的性质和使用的非线性工具，并确定了数据采集和处理的方法。结论：所审查的文章表明，疲劳主要在等距收缩中导致复杂性降低，但这在动态收缩中并不清楚。这种疲劳引起的复杂性丧失似乎是中枢神经系统变化的结果，尽管是由外围机制触发的。应该注意的是，非线性工具受收缩的相对强度的影响，非平稳性，以及信号的获取和处理。
