Effect of accelerometer location on mechanomyogram variables during voluntary, constant-force contractions in three human muscles
Effect of accelerometer location on mechanomyogram variables during voluntary, constant-force contractions in three human muscles
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DOI：
10.1007/bf02351021
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发表时间：
2004-01-01
影响因子：
3.2
通讯作者：
Orizio, C
中科院分区：
文献类型：
--
作者：
Cescon, C;Farina, D;Orizio, C
为了更好地了解不同的力水平和肌肉结构的机械肌电（MMG）的功能，MMG信号检测在许多点沿着三块肌肉的MMG传感器（多达八个）的线性阵列的应用程序在皮肤上进行了分析。记录10名健康男性受试者优势侧肱二头肌、胫骨前肌和上腹肌的MMG信号。加速度计沿着肌肉纤维的方向排列。一个加速度计位于远端肌肉神经支配区，其他六个或七个加速度计放置在肌肉上，形成一个传感器阵列，它们之间的距离固定。在所有情况下，阵列几乎覆盖整个肌肉长度。从相邻加速度计检测到的MMG信号具有相似的形状，相关系数在约0.5至约0.9的范围内。MMG振幅和特征谱频率显著依赖于加速度计位置。MMG振幅在肱二头肌和胫骨前肌的肌腹处最大。较高的MMG特征频谱频率与较高的振幅的情况下，肱二头肌，而胫骨前肌观察到相反的。在上小脑，特征频谱频率，MMG振幅和收缩力之间的关系取决于加速度计的位置。这表明，MMG的频谱特征不仅反映了招募的肌肉纤维的力学性能，但取决于肌肉结构和运动单位的领土分布。得出的结论是，加速度计的位置可以有振幅和频谱MMG功能的影响，这种依赖性时，MMG信号用于肌肉评估应予以考虑。
To understand better the features of the mechanomyogram (MMG) with different force levels and muscle architectures, the MMG signals detected at many points along three muscles were analysed by the application of a linear array of MMG sensors (up to eight) over the skin. MMG signals were recorded from the biceps brachii, tibialis anterior and upper trapezius muscles of the dominant side of ten healthy male subjects. The accelerometers were aligned along the direction of the muscle fibres. One accelerometer was located over the distal muscle innervation zone, and the other six or seven accelerometers were placed over the muscle, forming an array of sensors with fixed distances between them. The array covered almost the entire muscle length in all cases. MMG signals detected from adjacent accelerometers had similar shapes, with correlation coefficients ranging from about 0.5 to about 0.9. MMG amplitude and characteristic spectral frequencies significantly depended on accelerometer location. The MMG amplitude was maximum at the muscle belly for the biceps brachii and the tibialis anterior. Higher MMG characteristic spectral frequencies were associated with higher amplitudes in the case of the biceps brachii, whereas the opposite was observed for the tibialis anterior muscle. In the upper trapezius, the relationship between characteristic spectral frequencies, MMG amplitude and contraction force depended on the accelerometer location. This suggested that MMG spectral features do not only reflect the mechanical properties of the recruited muscle fibres but depend on muscle architecture and motor unit territorial distribution. It was concluded that the location of the accelerometer can have an influence on both amplitude and spectral MMG features, and this dependence should be considered when MMG signals are used for muscle assessment.