Anti-phase action between the angular accelerations of trunk and leg is reduced in the elderly
Anti-phase action between the angular accelerations of trunk and leg is reduced in the elderly
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DOI：
10.1016/j.gaitpost.2014.03.006
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发表时间：
2014-05-01
期刊：
影响因子：
2.4
通讯作者：
Nozaki, Daichi
中科院分区：
文献类型：
--
作者：
Kato, Tomohisa;Yamamoto, Shin-ichiro;Nozaki, Daichi
人类安静的站立姿势通常被建模为围绕踝关节旋转的单个倒立摆。然而，最近的研究表明，腿和躯干段之间的反相作用通过降低身体质心（COM）的加速度在稳定姿势中起着重要作用。本研究的目的是测试的假设，即反相行动是衰减在老年人相比，年轻人。采用4个激光位移传感器测量了22名健康青年受试者（年龄范围20-35岁）和38名健康老年受试者（年龄范围57-80岁）安静站立30 s两次的下肢和躯干节段的前后运动。为了关注躯干和腿之间的节段动作，我们应用了约束（即，木夹板）上的每一个部分。我们发现，COM的速度和加速度（时间序列的标准差进行评估）显着高于老年受试者比年轻受试者。COM的加速度的增加不仅是由于段的角加速度的增加，而且还由于它们的反相关系的减少，如量化两个段之间的抵消程度的指数所示。我们的结论是，在安静站立期间，老年受试者的躯干和腿段之间的反相作用的程度小于年轻受试者，并且由于衰老引起的反相作用的这种变化导致老年受试者的COM加速度增加。(C)2014年爱思唯尔B。V.保留所有权利。
Quiet standing posture in humans has often been modeled as a single inverted pendulum pivoting around the ankle joint. However, recent studies have suggested that anti-phase action between leg and trunk segments plays a significant role in stabilizing posture by reducing the acceleration of the center of mass (COM) of the body. The aim of this study is to test the hypothesis that anti-phase action is attenuated in the elderly compared to the young. The anterior-posterior movements of leg and trunk segments were measured using 4 laser displacement sensors from 22 healthy young subjects (age range, 20-35 years) and 38 healthy elderly subjects (age range, 57-80 years) standing quietly for 30 s twice. To focus on the segmental action between trunk and legs, we applied constraints (i.e., wooden splints) on each segment. We found that the velocity and acceleration of the COM (standard deviation of the time series was evaluated) were significantly higher for the elderly subjects than for young subjects. The increase in the acceleration of the COM resulted not only from an increase in the angular acceleration of the segments but also from the reduction of their anti-phase relationship, as demonstrated by an index that quantifies the degree of cancelation between both segments. We conclude that the degree of anti- phase action between trunk and leg segments during quiet standing is smaller for elderly subjects than for young subjects, and that this change of the anti-phase action due to aging resulted in increased COM acceleration in the elderly subjects. (C) 2014 Elsevier B. V. All rights reserved.