A novel approach to measure variability in the anterior cruciate ligament deficient knee during walking: the use of the approximate entropy in orthopaedics.
A novel approach to measure variability in the anterior cruciate ligament deficient knee during walking: the use of the approximate entropy in orthopaedics.
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DOI：
10.1007/s10877-006-1032-7
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发表时间：
2006-02-01
影响因子：
2.2
通讯作者：
Stergiou, Nicholas
中科院分区：
文献类型：
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作者：
Georgoulis, Anastasios D;Moraiti, Constantina;Stergiou, Nicholas
目的：通过近似熵等方法评价生物节律活动的可变性，为心脏病学和神经病学等学科提供了重要的病理学信息。这项研究导致了“复杂性损失假说”，在该假说中，变异性的降低与健康灵活性的丧失有关，从而使系统变得更加僵硬，无法适应压力。ApEn作为变异性和复杂性的一种度量，与病理学有很好的相关性，在某些情况下，它可以预测随后的临床变化。由于人体步态也是一种节律性的振荡，因此近似熵的应用对人体步态的研究是有益的。我们的目的是评估前交叉韧带缺陷膝关节的可变性，因为前交叉韧带断裂是一种常见的肌肉骨骼损伤，并伴随着步态模式的改变和关节未来的病理变化。我们假设前交叉韧带缺陷的膝关节将表现出比对侧完整膝关节更规则和更少变化的步行模式。方法：10名单侧膝关节缺陷的受试者以他们自己选择的速度在跑步机上行走，分别快20%和慢20%，同时收集每种情况下连续80步的运动学数据(50赫兹)。结果：在所有速度下，前交叉韧带缺陷膝关节的近似熵均显著小于健侧(F=5.57，p=0.022)。随着步行速度的增加，ApEn值显著增加(F=5.79，p=0.005)。结论：前交叉韧带缺陷膝关节的特征改变，表现出比对侧完整膝关节更规则和更少变化的模式，可能会降低系统的适应性，使其对扰动的适应能力降低。这可以解释在膝关节缺陷中发现的未来病理增加的原因。ApEn可作为评估骨科病理和治疗干预的重要工具。
OBJECTIVE: The evaluation of variability of biological rhythmic activities through measures such as Approximate Entropy (ApEn) has provided important information regarding pathology in disciplines such as cardiology and neurology. This research lead to the "loss of complexity hypothesis" where decreased variability is associated with loss of healthy flexibility rendering the system more rigid and unable to adapt to stresses. ApEn as a measure of variability and complexity, correlates well with pathology while, in some cases, it is predictive of subsequent clinical changes. The study of human gait could benefit from the application of ApEn since it is also a rhythmical oscillation. Our aim was to assess the variability of the ACL deficient knee, since ACL rupture is a common musculoskeletal injury and is accompanied by altered gait patterns and future pathology in the joint. We hypothesized that the ACL deficient knee will exhibit more regular and less variable walking patterns than the contralateral intact knee.METHODS: Ten subjects with unilateral deficiency walked on a treadmill at their self-selected speed, 20% faster, and 20% slower, while kinematics were collected (50 Hz) from 80 consecutive strides for each condition. The ApEn of the resulted knee joint flexion-extension time series was calculated.RESULTS: Significantly smaller ApEn values were found in the ACL deficient knee when compared with the contralateral intact (F = 5.57, p = 0.022), for all speeds. ApEn values significantly increased (F = 5.79, p = 0.005) with increases in walking speed.CONCLUSIONS: The altered properties of the ACL deficient knee, which exhibits more regular and less variable patterns than the contralateral intact knee, may decrease the adaptability of the system rendering it less able to adjust to perturbations. This could explain the increased future pathology found in the deficient knee. ApEn can be an important tool in assessing pathology and therapeutic interventions in orthopaedics.