Document Detail

Simulation and analysis of the electromyographic interference pattern in normal muscle. Part II: Activity, upper centile amplitude, and number of small segments.
MedLine Citation:
PMID:  3736582     Owner:  NLM     Status:  MEDLINE    
We have defined three new features of the electromyographic (EMG) interference pattern (IP): activity, upper centile amplitude (UCA), and number of small segments (NSS). These parameters were measured in simulated IPs constructed by adding together motor unit action potentials (MUAPs) recorded with a concentric needle EMG electrode. The activity increases linearly with the number of MUAP discharges to approximately 80% of its theoretical maximum value. The UCA correlates strongly with the peak-to-peak amplitude of the largest MUAP in the IP and the mean segment amplitude and does not depend on the discharge rate of the largest MUAPs. We infer that the UCA defines the upper limit of the peak-to-peak amplitude of the MUAPs contained in the IP. The NSS increases with the number of MUAP discharges, but reaches a constant value at higher MUAP discharge rates, probably because small amplitude MUAPs are masked by the large amplitude MUAPs. The potential value of these parameters in automated IP analysis is discussed.
S D Nandedkar; D B Sanders; E V Stålberg
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Muscle & nerve     Volume:  9     ISSN:  0148-639X     ISO Abbreviation:  Muscle Nerve     Publication Date:    1986 Jul-Aug
Date Detail:
Created Date:  1986-09-17     Completed Date:  1986-09-17     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7803146     Medline TA:  Muscle Nerve     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  486-90     Citation Subset:  IM    
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MeSH Terms
Action Potentials
Electromyography / methods*
Middle Aged
Motor Neurons / physiology*
Muscles / innervation*
Reference Values

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

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