A Biomechanical Study of Muscle Torque as Affected by Motor Unit Activity, Length-Tension Relationship and Muscle Force Lever

2015 ◽  
pp. 675-682
Author(s):  
U. Moritz ◽  
G. Svantesson ◽  
D. Haffajee
Keyword(s):  
Motor Unit ◽  
Unit Activity ◽  
Muscle Force ◽  
Biomechanical Study ◽  
Muscle Torque ◽  
Motor Unit Activity

Predicting Skeletal Muscle Force from Motor‐Unit Activity using a 3D FE Model

PAMM ◽  
2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Harnoor Saini ◽  
Ekin Altan ◽  
Ellankavi Ramasamy ◽  
Thomas Klotz ◽  
Leonardo Gizzi ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Motor Unit ◽  
Unit Activity ◽  
Muscle Force ◽  
Fe Model ◽  
Motor Unit Activity

Blockade of 5-HT2 receptors suppresses rate of torque development and motor unit discharge rate during rapid contractions

2021 ◽  
Author(s):  
Benjamin Ian Goodlich ◽  
Sean A Horan ◽  
Justin J Kavanagh
Keyword(s):  
Motor Unit ◽  
Unit Activity ◽  
Repeated Measures ◽  
Discharge Rate ◽  
Voluntary Contraction ◽  
Unit Discharge ◽  
Motor Unit Activity ◽  
Rate Of Torque Development ◽  
Motor Unit Discharge ◽  
Torque Development

Serotonin (5-HT) is a neuromodulator that is critical for regulating the excitability of spinal motoneurons and the generation of muscle torque. However, the role of 5-HT in modulating human motor unit activity during rapid contractions has yet to be assessed. Nine healthy participants (23.7 ± 2.2 yr) ingested 8 mg of the competitive 5-HT2 antagonist cyproheptadine in a double-blinded, placebo-controlled, repeated-measures experiment. Rapid dorsiflexion contractions were performed at 30%, 50% and 70% of maximal voluntary contraction (MVC), where motor unit activity was assessed by high-density surface electromyographic decomposition. A second protocol was performed where a sustained, fatigue-inducing dorsiflexion contraction was completed prior to undertaking the same 30%, 50% and 70% MVC rapid contractions and motor unit analysis. Motor unit discharge rate (p < 0.001) and rate of torque development (RTD; p = 0.019) for the unfatigued muscle were both significantly lower for the cyproheptadine condition. Following the fatigue inducing contraction, cyproheptadine reduced motor unit discharge rate (p < 0.001) and RTD (p = 0.024), where the effects of cyproheptadine on motor unit discharge rate and RTD increased with increasing contraction intensity. Overall, these results support the viewpoint that serotonergic effects in the central nervous system occur fast enough to regulate motor unit discharge rate during rapid powerful contractions.

scholarly journals An Analysis or the single Motor Unit Activity Involved in Oro-facial Functions

1986 ◽  
Vol 4 ◽  
pp. 115-122
Author(s):  
Hideho Handa ◽  
Yukihiro Fujita ◽  
Yasuyo Nomora ◽  
Hiroshi Suzuki ◽  
Kazuo Toda ◽  
...  
Keyword(s):  
Motor Unit ◽  
Unit Activity ◽  
Single Motor Unit ◽  
Single Motor ◽  
Motor Unit Activity

scholarly journals Myokymia and impaired muscular relaxation with continuous motor unit activity.

1979 ◽  
Vol 42 (6) ◽  
pp. 557-562 ◽  
Author(s):  
F D Lublin ◽  
P Tsairis ◽  
L J Streletz ◽  
R A Chambers ◽  
W F Riker ◽  
...  
Keyword(s):  
Motor Unit ◽  
Unit Activity ◽  
Muscular Relaxation ◽  
Motor Unit Activity ◽  
Continuous Motor Unit Activity
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