Distribution of muscle fibre conduction velocity for representative samples of motor units in the full recruitment range of the tibialis anterior muscle
Distribution of muscle fibre conduction velocity for representative samples of motor units in the full recruitment range of the tibialis anterior muscle
复制标题
DOI：
10.1111/apha.12930
复制
发表时间：
2018-02-01
影响因子：
6.3
通讯作者：
Farina, D.
中科院分区：
文献类型：
--
作者：
Del Vecchio, A.;Negro, F.;Farina, D.
AimMotor根据运动神经元的大小有序地招募单位。此外，由于较大的运动神经元比较小的运动神经元支配直径较大的纤维，因此应根据其传导速度(MUCV)顺序招募运动单位。由于技术的限制，这些关系以前已经间接或在小型运动单位样本中进行了测试，这些样本显示运动单位招募阈值(RT)和MUCV之间的弱相关性。在此，我们分析了大样本运动单位的MUCV和RT的关系。方法10名健康志愿者完成了一系列最大力的70%的等长踝背屈运动。从胫前肌记录的多道表面肌电信号分解为单个运动单位动作电位，计算出相应的运动单位RT、MUCV和动作电位幅度。结果在个体内，肌纤维直径和肌纤维直径呈单峰分布，无明显的群体分布。MUCV与RT显著相关(Mean(SD)R-2=0.7(0.09)，P
AimMotor units are recruited in an orderly manner according to the size of motor neurones. Moreover, because larger motor neurones innervate fibres with larger diameters than smaller motor neurones, motor units should be recruited orderly according to their conduction velocity (MUCV). Because of technical limitations, these relations have been previously tested either indirectly or in small motor unit samples that revealed weak associations between motor unit recruitment threshold (RT) and MUCV. Here, we analyse the relation between MUCV and RT for large samples of motor units.MethodsTen healthy volunteers completed a series of isometric ankle dorsiflexions at forces up to 70% of the maximum. Multi-channel surface electromyographic signals recorded from the tibialis anterior muscle were decomposed into single motor unit action potentials, from which the corresponding motor unit RT, MUCV and action potential amplitude were estimated. Established relations between muscle fibre diameter and CV were used to estimate the fibre size.ResultsWithin individual subjects, the distributions of MUCV and fibre diameters were unimodal and did not show distinct populations. MUCV was strongly correlated with RT (mean (SD) R-2=0.7 (0.09), P