Estimation of elbow flexion force during isometric muscle contraction from mechanomyography and electromyography

2010 ◽  
Vol 48 (11) ◽  
pp. 1149-1157 ◽  
Author(s):  
Wonkeun Youn ◽  
Jung Kim
Keyword(s):  
Muscle Contraction ◽  
Elbow Flexion ◽  
Isometric Muscle Contraction ◽  
Flexion Force ◽  
Isometric Muscle

scholarly journals Effects of assistive force on the agonist and antagonist muscles in elbow flexion

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Nursalbiah Nasir ◽  
Keisuke Hayashi ◽  
Ping Yeap Loh ◽  
Satoshi Muraki
Keyword(s):  
Muscle Contraction ◽  
Perceived Exertion ◽  
Elbow Flexion ◽  
Emg Activity ◽  
Antagonist Muscle ◽  
Isometric Muscle Contraction ◽  
Antagonist Muscles ◽  
Agonist And Antagonist ◽  
Agonist And Antagonist Muscles ◽  
Isometric Muscle

This study investigated the responses of the agonist and antagonist muscles against assistive force during isometric muscle contraction. Participants performed isometric elbow flexion at 90º for 30 seconds under two workload conditions (20% and 40% of the maximal voluntary workload) with three levels of assistive force (0%, 50%, and 100% theoretical effectiveness) for 10 seconds. Electromyography (EMG) of the biceps (agonist muscle) and triceps (antagonist muscle) was measured during the task, and perceived exertion was obtained after the task. Assistive force significantly reduced EMG activity in the agonist muscle and the perceived exertion score only at 40% workload. However, the reduction of EMG activity and perceived exertion score were lower than that for the physical estimated effect. In addition, the EMG activity in the antagonist muscle was not influenced, irrespective of workload conditions and the level of assistive force. These results suggested that although the assistive force during isometric muscle contraction relieves exertion of the agonist muscle that accompanies the decrease in perceived exertion, their assistive effects are influenced by various human physiological and anatomical factors. 

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

Rostral ventrolateral medullary opioid receptor activation modulates pressor response to muscle contraction

1998 ◽  
Vol 274 (1) ◽  
pp. H139-H146 ◽  
Author(s):  
Daryl Caringi ◽  
David J. Mokler ◽  
David M. Koester ◽  
Ahmmed Ally
Keyword(s):  
Muscle Contraction ◽  
Nerve Stimulation ◽  
Tibial Nerve ◽  
Pressor Response ◽  
Cardiovascular Responses ◽  
Receptor Activation ◽  
Ventrolateral Medulla ◽  
Tibial Nerve Stimulation ◽  
Isometric Muscle Contraction ◽  
Isometric Muscle

The effects of an opioid agonist, [d-Ala2]methionine enkephalinamide (DAME), administered into the rostral ventrolateral medulla (rVLM) or caudal ventrolateral medulla (cVLM) on cardiovascular responses to isometric muscle contraction were determined in anesthetized rats. A 30-s contraction evoked by tibial nerve stimulation increased mean arterial pressure (MAP) and heart rate (HR) by 34 ± 6 mmHg and 40 ± 7 beats/min, respectively, with a developed tension of 322 ± 30 g, after bilateral insertion of microdialysis probes into the rVLM. Thirty-minute dialysis of DAME (10 and 100 μM) attenuated the contraction-evoked cardiovascular changes dose dependently (10 μM: MAP = 25 ± 4 mmHg, HR = 27 ± 3 beats/min, tension = 333 ± 25 g; 100 μM: MAP = 14 ± 4 mmHg, HR = 16 ± 5 beats/min, tension = 330 ± 34 g). Preadministration of an opioid antagonist, naloxone (100 μM), augmented contraction-evoked MAP and HR responses and blocked effects of 100 μM DAME. Microdialysis of DAME into the cVLM produced no changes in the pressor response to contraction. At end of each experiment, tibial nerve stimulation after neuromuscular blockade evoked no MAP or HR change. Results demonstrate that opioid receptor activation within the rVLM modulates cardiovascular responses to isometric muscle contraction.

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