Document Detail


Effects of repetitive dynamic contractions upon electromechanical delay.
MedLine Citation:
PMID:  10052658     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effect of repeated maximal effort isotonic contractions on electromechanical delay was studied. Over 4 days, 17 male subjects performed 400 rapid elbow flexion trials. The kinematics and surface electromyographic (EMG) activity of the biceps brachii of these subjects were recorded. The period from the onset of the EMG until the beginning of movement was defined as the electromechanical delay. The period from the beginning of movement until the end of the EMG was defined as the second component of the contraction. Over the 4 day period there was an increase in the speed of limb movement. The mean power frequency and the duration of the EMG during the electromechanical delay did not change, while the root-mean-square amplitude increased. The duration of the EMG during the second component of the contraction remained stable. The mean power frequency and the root-mean-square amplitude of the EMG during the second component of the contraction increased with the speed of limb movement. We conclude that the faster contractions were a result of changes in motor unit recruitment during the second component of the contraction, rather than in the electromechanical delay.
Authors:
D A Gabriel; J P Boucher
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Publication Detail:
Type:  Clinical Trial; Journal Article    
Journal Detail:
Title:  European journal of applied physiology and occupational physiology     Volume:  79     ISSN:  0301-5548     ISO Abbreviation:  Eur J Appl Physiol Occup Physiol     Publication Date:  1998 Dec 
Date Detail:
Created Date:  1999-05-07     Completed Date:  1999-05-07     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0410266     Medline TA:  Eur J Appl Physiol Occup Physiol     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  37-40     Citation Subset:  IM    
Affiliation:
Physical Therapy Department, School of Allied Health Science, East Carolina University, Greenville, NC 27858-4353, USA.
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MeSH Terms
Descriptor/Qualifier:
Adult
Arm / physiology
Elbow / physiology
Electromyography
Humans
Isotonic Contraction / physiology
Male
Muscle, Skeletal / physiology*
Recruitment, Neurophysiological / physiology

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