Document Detail

Neuromuscular activation of triceps surae using muscle functional MRI and EMG.
MedLine Citation:
PMID:  15809557     Owner:  NLM     Status:  MEDLINE    
PURPOSE: The aim of the present study was to clarify the neuromuscular activation patterns among individual triceps surae (TS) muscles during a repetitive plantarflexion using muscle functional magnetic resonance imaging (MRI) (mfMRI) and electromyography (EMG). METHODS: Six healthy men participated in this study, performing 5 sets of 10 repetitions of a calf-raise exercise bilaterally, unilaterally, and unilaterally with an additional 15% of body-weight load. The transverse relaxation times (T2) in the medial gastrocnemius (MG), lateral gastrocnemius (LG), and soleus (SOL) muscles were measured from mfMR images obtained with the subject at rest and immediately after exercise; integrated EMG (iEMG) activity was recorded from the same muscles during exercise using surface electrodes. RESULTS: There was remarkable correspondence between the changes in T2 values and iEMG activity under the three different workloads for individual TS muscles. In addition, changes in T2 value that occurred as a function of increasing exercise loads were linearly correlated with iEMG activity in the MG (r=0.58, P<0.05) and SOL (r=0.63, P<0.01), but not in the LG. CONCLUSIONS: These results suggest that 1) mfMRI signals and iEMG activity correlate with workload in individual TS muscles, 2) mfMRI signals are associated with neuromuscular activity reflected in iEMG in the MG and SOL but not in the LG, and 3) these relationships are associated with neuromuscular and metabolic factors during exercise.
Ryuta Kinugasa; Hiroshi Akima
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Medicine and science in sports and exercise     Volume:  37     ISSN:  0195-9131     ISO Abbreviation:  Med Sci Sports Exerc     Publication Date:  2005 Apr 
Date Detail:
Created Date:  2005-04-05     Completed Date:  2005-06-30     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8005433     Medline TA:  Med Sci Sports Exerc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  593-8     Citation Subset:  IM; S    
Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, JAPAN.
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MeSH Terms
Analysis of Variance
Electromyography / methods
Leg / physiology*
Magnetic Resonance Imaging*
Muscle, Skeletal / physiology*
Neuromuscular Junction / physiology

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

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