Bayram Mehmed Bugrahan, Siemionow Vlodek, Yue Guang H
Department of Medical Engineering, Acibadem University, Istanbul, Turkey. Human Performance and Engineering Research, Kessler Foundation, West Orange, New Jersey. Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Ohio.
Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Ohio. Department of Physical Medicine and Rehabilitation, Neurological Institute, Cleveland Clinic, Ohio.
J Gerontol A Biol Sci Med Sci. 2015 Aug;70(8):1037-43. doi: 10.1093/gerona/glv014. Epub 2015 Mar 16.
Aging is associated with muscle weakness and impairment in performing skilled motor tasks. Still, little is known about whether the link or functional coupling or connection between the central and peripheral systems during voluntary motor performance is compromised in the elderly subjects. The purposes of this study were to estimate functional corticomuscular connection (CMC) strength in the elderly subjects by calculating EEG-EMG coherence during voluntary motor performance, determine the relationship between the CMC and voluntary muscle force, and compare these between the old and the young subjects.
Maximal voluntary contraction (MVC) of elbow flexion (EF) and EFs at three submaximal (20%, 50%, and 80% MVC) levels were performed in 28 healthy older (74.96±1.32 years) and 20 young (22.60±0.90 years) individuals, while EEG and EMG from biceps brachii, brachioradialis, and triceps brachii muscles were recorded simultaneously.
Compared with the young, older individuals exhibited significantly weakened CMC at all force levels tested. There was a proportional relationship between the CMC and EF force and high-positive correlation between the CMC and EF strength in both groups.
Weakened CMC in aging may be a major factor contributing to age-related muscle weakness, and the linear relationship between the CMC and voluntary muscle force suggests dependence of force output on translation of the descending command to muscle electrical signal.
衰老与肌肉无力以及执行复杂运动任务的能力受损有关。然而，对于老年受试者在自主运动表现过程中，中枢和外周系统之间的联系、功能耦合或连接是否受到损害，我们知之甚少。本研究的目的是通过计算自主运动表现期间的脑电图-肌电图相干性来估计老年受试者的功能性皮质-肌肉连接（CMC）强度，确定CMC与自主肌肉力量之间的关系，并比较老年和年轻受试者之间的这些关系。
对28名健康老年人（74.96±1.32岁）和20名年轻人（22.60±0.90岁）进行了肘关节屈曲（EF）的最大自主收缩（MVC）以及三个次最大收缩水平（20%、50%和80%MVC）的EF测试，同时记录肱二头肌、肱桡肌和肱三头肌的脑电图和肌电图。
与年轻人相比，老年人在所有测试的力量水平下均表现出明显减弱的CMC。两组中，CMC与EF力量之间存在比例关系，CMC与EF强度之间存在高度正相关。
衰老过程中CMC减弱可能是导致与年龄相关的肌肉无力的主要因素，并且CMC与自主肌肉力量之间的线性关系表明力量输出依赖于下行指令向肌肉电信号的转化。
