Document Detail


Chest wall and trunk muscle activity during inspiratory loading.
MedLine Citation:
PMID:  1490946     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We measured the electromyographic (EMG) activity in four chest wall and trunk (CWT) muscles, the erector spinae, latissimus dorsi, pectoralis major, and trapezius, together with the parasternal, in four normal subjects during graded inspiratory efforts against an occlusion in both upright and seated postures. We also measured CWT EMGs in six seated subjects during inspiratory resistive loading at high and low tidal volumes [1,280 +/- 80 (SE) and 920 +/- 60 ml, respectively]. With one exception, CWT EMG increased as a function of inspiratory pressure generated (Pmus) at all lung volumes in both postures, with no systematic difference in recruitment between CWT and parasternal muscles as a function of Pmus. At any given lung volume there was no consistent difference in CWT EMG at a given Pmus between the two postures (P > 0.09). However, at a given Pmus during both graded inspiratory efforts and inspiratory resistive loading, EMGs of all muscles increased with lung volume, with greater volume dependence in the upright posture (P < 0.02). The results suggest that during inspiratory efforts, CWT muscles contribute to the generation of inspiratory pressure. The CWT muscles may act as fixators opposing deflationary forces transmitted to the vertebral column by rib cage articulations, a function that may be less effective at high lung volumes if the direction of the muscular insertions is altered disadvantageously.
Authors:
S J Cala; J Edyvean; L A Engel
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  73     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1992 Dec 
Date Detail:
Created Date:  1993-02-26     Completed Date:  1993-02-26     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2373-81     Citation Subset:  IM; S    
Affiliation:
Thoracic Medicine Unit, Westmead Hospital, New South Wales, Australia.
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MeSH Terms
Descriptor/Qualifier:
Adult
Airway Resistance / physiology
Electrodes
Electromyography
Female
Gravitation
Humans
Male
Respiratory Mechanics / physiology*
Respiratory Muscles / physiology*
Thorax / physiology*
Tidal Volume / physiology

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


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