The effects of electrode placement and innervation zone location on the electromyographic amplitude and mean power frequency versus isometric torque relationships for the vastus lateralis muscle

2008 ◽  
Vol 18 (2) ◽  
pp. 317-328 ◽  
Author(s):  
Travis W. Beck ◽  
Terry J. Housh ◽  
Joel T. Cramer ◽  
Joseph P. Weir
Motor Control ◽  
2021 ◽  
Vol 25 (1) ◽  
pp. 59-74
Author(s):  
Taylor K. Dinyer ◽  
Pasquale J. Succi ◽  
M. Travis Byrd ◽  
Caleb C. Voskuil ◽  
Evangeline P. Soucie ◽  
...  

This study determined the load- and limb-dependent neuromuscular responses to fatiguing, bilateral, leg extension exercise performed at a moderate (50% one-repetition maximum [1RM]) and high load (80% 1RM). Twelve subjects completed 1RM testing for the bilateral leg extension, followed by repetitions to failure at 50% and 80% 1RM, on separate days. During all visits, the electromyographic (EMG) and mechanomyographic (MMG), amplitude (AMP) and mean power frequency (MPF) signals were recorded from the vastus lateralis of both limbs. There were no limb-dependent responses for any of the neuromuscular signals and no load-dependent responses for EMG AMP, MMG AMP, or MMG MPF (p = .301–.757), but there were main effects for time that indicated increases in EMG and MMG AMP and decreases in MMG MPF. There was a load-dependent decrease in EMG MPF over time (p = .032) that suggested variability in the mechanism responsible for metabolite accumulation at moderate versus high loads. These findings suggested that common drive from the central nervous system was used to modulate force during bilateral leg extension performed at moderate and high loads.


2006 ◽  
Vol 155 (1) ◽  
pp. 126-133 ◽  
Author(s):  
Moh H. Malek ◽  
Jared W. Coburn ◽  
Joseph P. Weir ◽  
Travis W. Beck ◽  
Terry J. Housh

2009 ◽  
Vol 41 ◽  
pp. 199-200
Author(s):  
Clayton Camic ◽  
Michelle Mielke ◽  
C. Russell Hendrix ◽  
Jorge Zuniga ◽  
Terry J. Housh ◽  
...  

2005 ◽  
Vol 21 (1) ◽  
pp. 96-109 ◽  
Author(s):  
Travis W. Beck ◽  
Terry J. Housh ◽  
Glen O. Johnson ◽  
Joseph P. Weir ◽  
Joel T. Cramer ◽  
...  

This study compared the patterns of mechanomyographic (MMG) amplitude and mean power frequency vs. torque relationships in men and women during isometric muscle actions of the biceps brachii. Seven men (mean age 23.9 ± 3.5 yrs) and 8 women (mean 21.0 ± 1.3 yrs) performed submaximal to maximal isometric muscle actions of the dominant forearm flexors. Following determination of the isometric maximum voluntary contraction (MVC), they randomly performed submaximal step muscle actions in 10% increments from 10% to 90% MVC. Polynomial regression analyses indicated that the MMG amplitude vs. isometric torque relationship for the men was best fit with a cubic model (R2= 0.983), where MMG amplitude increased slightly from 10% to 20% MVC, increased rapidly from 20% to 80% MVC, and plateaued from 80% to 100% MVC. For the women, MMG amplitude increased linearly (r2= 0.949) from 10% to 100% MVC. Linear models also provided the best fit for the MMG mean power frequency vs. isometric torque relationship in both the men (r2= 0.813) and women (r2= 0.578). The results demonstrated gender differences in the MMG amplitude vs. isometric torque relationship, but similar torque-related patterns for MMG mean power frequency. These findings suggested that the plateau in MMG amplitude at high levels of isometric torque production for the biceps brachii in the men, but not the women, may have been due to greater isometric torque, muscle stiffness, and/or intramuscular fluid pressure in the men, rather than to differences in motor unit activation strategies for modulating isometric torque production.


2015 ◽  
Vol 47 ◽  
pp. 549 ◽  
Author(s):  
Christoher A. Fahs ◽  
Jeremy P. Loenneke ◽  
Robert S. Thiebaud ◽  
Lindy M. Rossow ◽  
Daeyeol Kim ◽  
...  

2015 ◽  
Vol 25 (3) ◽  
pp. 423-430 ◽  
Author(s):  
Trent J. Herda ◽  
Jorge M. Zuniga ◽  
Eric D. Ryan ◽  
Clayton L. Camic ◽  
Haley C. Bergstrom ◽  
...  

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