Document Detail

Spectral analysis of muscular sound during isometric contraction of biceps brachii.
MedLine Citation:
PMID:  2318762     Owner:  NLM     Status:  MEDLINE    
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.
C Orizio; R Perini; B Diemont; M Maranzana Figini; A Veicsteinas
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  68     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1990 Feb 
Date Detail:
Created Date:  1990-05-01     Completed Date:  1990-05-01     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  508-12     Citation Subset:  IM    
Dipartimento di Scienze Biomediche e Biotechnologie, Università di Brescia, Italy.
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MeSH Terms
Isometric Contraction / physiology*
Muscle Contraction / physiology*
Muscles / physiology*
Sound Spectrography

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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