Motor unit activation order during electrically evoked contractions of paralyzed or partially paralyzed muscles

2002 ◽  
Vol 25 (6) ◽  
pp. 797-804 ◽  
Author(s):  
Christine K. Thomas ◽  
Gary Nelson ◽  
Lara Than ◽  
Inge Zijdewind
2017 ◽  
Vol 95 (4) ◽  
pp. 404-419 ◽  
Author(s):  
Howard J. Green ◽  
Don Ranney ◽  
Natasha Kyle ◽  
David Lounsbury ◽  
Ian C. Smith ◽  
...  

This study assessed neuromuscular function in the extensor carpi radialis brevis (ECRB) of female workers diagnosed with work-related myalgia (WRM, n = 14, age 45.2 ± 1.9 years) and the ECRB of healthy controls (CON, n = 10, age 34.6 ± 2.5 years). Groups were compared on voluntary and electrically evoked functional responses at rest (Pre), immediately following a 5 min repetitive task (Post-0) performed at 60% maximal voluntary contraction (MVC), and after 5 min of recovery (Post-5). Despite near complete motor unit activation (MUA) (CON 98% ± 1% vs. WRM 99% ± 1%), at Pre, WRM produced 26% less (P < 0.05) MVC force than CON. Following an MVC, twitch force was increased (P < 0.05) by 94% ± 13% and 54% ± 11% in CON and WRM, respectively (CON vs. WRM; P < 0.05). The peak force and the maximal rates of force development and decline of electrically evoked contractions (10–100 Hz) were generally depressed (P < 0.05) at Post-0 and Post-5 relative to Pre. The response pattern to increasing frequencies of stimulation was not different (P > 0.05) between groups and MUA was not impaired (CON 97% ± 1% vs. WRM 97% ± 1%; P > 0.05). In conclusion, the peripheral weakness observed in the ECRB in WRM at rest does not result in abnormal fatigue or recovery responses after performing a task controlled for relative demand (60% MVC).


2018 ◽  
Vol 99 (4) ◽  
pp. 779-791 ◽  
Author(s):  
Trevor S. Barss ◽  
Emily N. Ainsley ◽  
Francisca C. Claveria-Gonzalez ◽  
M. John Luu ◽  
Dylan J. Miller ◽  
...  

2021 ◽  
Vol 121 (5) ◽  
pp. 1367-1377
Author(s):  
Stephanie A. Sontag ◽  
Michael A. Trevino ◽  
Trent J. Herda ◽  
Adam J. Sterczala ◽  
Jonathan D. Miller ◽  
...  

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