scholarly journals Motor Unit Activity during Fatiguing Isometric Muscle Contraction in Hemispheric Stroke Survivors

2017 ◽  
Vol 11 ◽  
Author(s):  
Lara McManus ◽  
Xiaogang Hu ◽  
William Z. Rymer ◽  
Nina L. Suresh ◽  
Madeleine M. Lowery
Keyword(s):  
Muscle Contraction ◽  
Motor Unit ◽  
Unit Activity ◽  
Stroke Survivors ◽  
Hemispheric Stroke ◽  
Motor Unit Activity ◽  
Isometric Muscle Contraction ◽  
Isometric Muscle

scholarly journals Actomyosin energy turnover declines while force remains constant during isometric muscle contraction

2004 ◽  
Vol 555 (1) ◽  
pp. 27-43 ◽  
Author(s):  
Timothy G. West ◽  
N. A. Curtin ◽  
Michael A. Ferenczi ◽  
Zhen-He He ◽  
Yin-Biao Sun ◽  
...  
Keyword(s):  
Muscle Contraction ◽  
Energy Turnover ◽  
Isometric Muscle Contraction ◽  
Isometric Muscle

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
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