Spectral analysis of muscular sound during isometric contraction of biceps brachii.
Spectral analysis of muscular sound during isometric contraction of biceps brachii.
复制标题
肱二头肌等长收缩时肌肉声音的频谱分析。
DOI：
--
复制
发表时间：
1990
影响因子：
3.3
通讯作者：
A. Veicsteinas
中科院分区：
文献类型：
--
作者：
C. Orizio;R. Perini;B. Diemont;M. Maranzana Figini;A. Veicsteinas
采用最大熵谱估计和快速傅立叶变换方法，对7名久坐不动的男性4名S的10次等长收缩[最大自主收缩的10~100%]时，在二头肌腹上方放置接触式传感器探头所测得的肌音频率成分进行了分析。随着MVC的增加，MS的功率谱变大，并趋于超过30%MVC的多峰。与该方法无关，平均频率在较低任务时约为11赫兹，然后在80%MVC时增加到15赫兹，在100%MVC时增加到22赫兹。当作用力增加时，15至45赫兹带宽(具有快抽动光纤的马达单元的发电率范围)中的相对功率从20%达到6至45赫兹带宽(具有慢和快抽动纤维的马达单元的发电率范围)中的55%。通过两种不同的建模方法得到的结果证实了声音信号的可靠性。此外，似乎可以从MS检索到运动单位激活模式。
The frequency content of muscular sound (MS), detected by placing a contact sensor transducer over the belly of the biceps brachii during 10 isometric contractions of 4 s each [10-100% of maximal voluntary contraction (MVC)] in seven sedentary men, was analyzed by the maximum entropy spectral estimation and the fast Fourier transform methods. With increasing %MVC, the power spectrum of the MS enlarges and tends to be multimodal beyond 30% MVC. Independent of the method, the mean frequency is approximately 11 Hz at the lower tasks, and then it increases up to 15 Hz at 80% MVC and to 22 Hz at 100% MVC. When the effort is increased the relative power in the 15- to 45-Hz bandwidth (range of firing rate of the motor units with fast-twitch fibers) from 20% reaches 55% of the power in the 6- to 45-Hz bandwidth (firing rate range of motor units with slow- and fast-twitch fibers). Our results obtained by the two different modeling approaches confirm the reliability of the sound signal. Moreover, it appears that from the MS the motor unit activation pattern can be retrieved.