Document Detail


Gastrocnemius and soleus muscle length, velocity, and EMG responses to changes in pedalling cadence.
MedLine Citation:
PMID:  16377214     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Several authors have shown different excitation patterns for soleus and gastrocnemius muscles in response to cadence manipulation during cycling. The purpose of this study was to examine gastrocnemius and soleus length and velocity change as a function of pedalling cadence to consider mechanisms underlying these excitation differences. Ten male and two female cyclists rode at five randomly assigned cadences (50, 65, 80, 95, and 110 rpm) at a nominal 200 W power output while EMG of the gastrocnemius and soleus and sagittal plane video were recorded. Joint-coordinate data for the knee and ankle were used with equations of Grieve et al. [Grieve D, Pheasant S, Cavanagh PR. Prediction of gastrocnemius length from knee and ankle joint posture, in: E. Asmussen, K. Jorgensen, editors. International Series on Biomechanics, vol. 2A, Baltimore: University Park Press; 1978. p. 405-412] to compute gastrocnemius and soleus length and velocity. Consistent with previous publications, gastrocnemius displayed a significant (p<0.05) increase in integrated EMG with increased cadence, whereas cadence had no significant effect on integrated EMG of the soleus. The ankle became significantly (p<0.05) more plantar flexed and reflected a reduced range of motion with increased cadence while the knee became significantly (p<0.05) less extended. Soleus decreased its range of motion by 29%, whereas gastrocnemius decreased its range of motion by 9%. In contrast, soleus increased its velocity range by 32% and gastrocnemius increased by 45%. These data show that with increased cadence gastrocnemius operated over a narrower range of operating lengths but at a higher range of shortening velocity than soleus. The higher range of velocity may have resulted in the need for a relatively higher excitation, as indicated by the integrated EMG, as the muscle was working at a different range on its force-velocity curve. During the recovery portion of the pedalling cycle, the soleus was acting eccentrically while the gastrocnemius acted concentrically indicating the triceps surae complex did not always act in unison.
Authors:
David J Sanderson; P E Martin; G Honeyman; J Keefer
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Publication Detail:
Type:  Journal Article     Date:  2006-01-11
Journal Detail:
Title:  Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology     Volume:  16     ISSN:  1050-6411     ISO Abbreviation:  J Electromyogr Kinesiol     Publication Date:  2006 Dec 
Date Detail:
Created Date:  2006-11-06     Completed Date:  2007-07-17     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9109125     Medline TA:  J Electromyogr Kinesiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  642-9     Citation Subset:  IM    
Affiliation:
School of Human Kinetics, University of British Columbia, 210-6081 University Boulevard, Vancouver BC, Canada V6T 1Z1. david.sanderson@ubc.ca
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MeSH Terms
Descriptor/Qualifier:
Adult
Analysis of Variance
Ankle / physiology
Ankle Joint / physiology
Bicycling*
Biomechanics
Electromyography
Ergometry
Female
Follow-Up Studies
Humans
Knee / physiology
Knee Joint / physiology
Male
Muscle Contraction
Muscle, Skeletal / physiology*
Posture
Range of Motion, Articular
Reflex

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


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