Muscle Force and Myoelectric Manifestations of Muscle Fatigue in Voluntary and Electrically Elicited Contractions

2016 ◽  
pp. 273-310 ◽  
Author(s):  
R. Merletti ◽  
B. Afsharipour ◽  
J. Dideriksen ◽  
D. Farina
Keyword(s):  
Muscle Fatigue ◽  
Muscle Force

The Effect of Heating and Cooling on Time Course of Voluntary and Electrically Induced Muscle Force Variation

Medicina ◽  
2011 ◽  
Vol 47 (1) ◽  
pp. 6 ◽  
Author(s):  
◽  
◽  
◽  
◽  
Keyword(s):  
Muscle Fatigue ◽  
Time Course ◽  
Muscle Force ◽  
Peak Torque ◽  
Voluntary Contraction ◽  
Knee Extensors ◽  
Lower Body ◽  
Heating And Cooling ◽  
Force Variation ◽  
Voluntary Contractions

The aim of this study was to investigate the effect of heating and cooling on time course of voluntary and electrically induced muscle force variation. Material and Methods. Ten volunteers performed 50 maximal voluntary and electrically induced contractions of the knee extensors at an angle of 120 degrees under the control conditions and after passive lower body heating and cooling in the control, heating, and cooling experiments. Peak torque, torque variation, and half-relaxation time were assessed during the exercise. Results. Passive lower body heating increased muscle and core temperatures, while cooling lowered muscle temperature, but did not affect core temperature. We observed significantly lower muscle fatigue during voluntary contraction compared with electrically induced contractions. Body heating (opposite to cooling) increased involuntarily induced muscle force, but caused greater electrically induced muscle fatigue. In the middle of the exercise, the coefficient of correlation for electrically induced muscle torque decreased significantly as compared with the beginning of the exercise, while during maximal voluntary contractions, this relation for torque remained significant until the end of the exercise. Conclusion. It was shown that time course of voluntary contraction was more stable than in electrically induced contractions.

scholarly journals Contraction frequency modulates muscle fatigue and the rate of myoglobin desaturation during incremental contractions in humans

2008 ◽  
Vol 33 (5) ◽  
pp. 915-921 ◽  
Author(s):  
Danielle M. Wigmore ◽  
Douglas E. Befroy ◽  
Ian R. Lanza ◽  
Jane A. Kent-Braun
Keyword(s):  
Muscle Fatigue ◽  
Muscle Force ◽  
Force Production ◽  
Metabolic Cost ◽  
Resonance Spectroscopy ◽  
Isometric Contractions ◽  
Metabolic Demand ◽  
Contraction Frequency ◽  
Duty Cycles ◽  
Force Time

The metabolic cost of force production, and therefore the demand for oxygen, increases with intensity and frequency of contraction. This study investigated the interaction between fatigue and oxygenation, as reflected by deoxymyoglobin (dMb), during slow and rapid rhythmic isometric contractions having the same duty cycles and relative force–time integrals (FTIs). We used 1H magnetic resonance spectroscopy and measures of dorsiflexor muscle force to compare dMb and fatigue (fall of maximal voluntary force, MVC) in 11 healthy adults (29 ± 7 y) during 16 min of slow (4 s contraction, 6 s relaxation) and rapid (1.2 s, 1.8 s) incremental (10%–80% MVC) contractions. We tested the hypotheses that (i) the rate of Mb desaturation would be faster in rapid than in slow contractions and (ii) fatigue, Mb desaturation, and the fall in FTI would be greater, and PO2 (oxygen tension) lower, at the end of rapid contractions than at the end of slow contractions. Although dMb increased more quickly during rapid contractions (p = 0.05), it reached a plateau at a similar level in both protocols (~42% max, p = 0.49), likely due to an inability to further increase force production and thus metabolic demand. Despite the similar dMb at the end of both protocols, fatigue was greater in rapid (56.6% ± 2.7% baseline) than in slow (69.5% ± 4.0%, p = 0.01) contractions. These results indicate that human skeletal muscle fatigue during incremental isometric contractions is in part a function of contraction frequency, possibly due to metabolic inhibition of the contractile process.

scholarly journals Gender Difference in Subjective Muscle-fatigue Sensation during Sustained Muscle Force Exertion

2008 ◽  
Vol 215 (3) ◽  
pp. 287-294 ◽  
Author(s):  
Shinichi Demura ◽  
Masakatsu Nakada ◽  
Yoshinori Nagasawa
Keyword(s):  
Gender Difference ◽  
Muscle Fatigue ◽  
Muscle Force

scholarly journals Is the notion of central fatigue based on a solid foundation?

2016 ◽  
Vol 115 (2) ◽  
pp. 967-977 ◽  
Author(s):  
Paola Contessa ◽  
Alessio Puleo ◽  
Carlo J. De Luca
Keyword(s):  
Muscle Fatigue ◽  
Muscle Force ◽  
Empirical Studies ◽  
Central Fatigue ◽  
Unit Force ◽  
The Central Nervous System ◽  
Solid Foundation ◽  
Exercise Induced ◽  
Voluntary Contractions ◽  
Central Factors

Exercise-induced muscle fatigue has been shown to be the consequence of peripheral factors that impair muscle fiber contractile mechanisms. Central factors arising within the central nervous system have also been hypothesized to induce muscle fatigue, but no direct empirical evidence that is causally associated to reduction of muscle force-generating capability has yet been reported. We developed a simulation model to investigate whether peripheral factors of muscle fatigue are sufficient to explain the muscle force behavior observed during empirical studies of fatiguing voluntary contractions, which is commonly attributed to central factors. Peripheral factors of muscle fatigue were included in the model as a time-dependent decrease in the amplitude of the motor unit force twitches. Our simulation study indicated that the force behavior commonly attributed to central fatigue could be explained solely by peripheral factors during simulated fatiguing submaximal voluntary contractions. It also revealed important flaws regarding the use of the interpolated twitch response from electrical stimulation of the muscle as a means for assessing central fatigue. Our analysis does not directly refute the concept of central fatigue. However, it raises important concerns about the manner in which it is measured and about the interpretation of the commonly accepted causes of central fatigue and questions the very need for the existence of central fatigue.

scholarly journals Efficiency of Voluntary Closing Hand and Hook Prostheses

2010 ◽  
Vol 34 (4) ◽  
pp. 411-427 ◽  
Author(s):  
Gerwin Smit ◽  
Dick H. Plettenburg
Keyword(s):  
Energy Dissipation ◽  
Muscle Fatigue ◽  
Research Program ◽  
Muscle Force ◽  
Test Bench ◽  
Test Results ◽  
Design Guideline ◽  
Pinch Force ◽  
Activation Force ◽  
Cable Forces

The Delft Institute of Prosthetics and Orthotics has started a research program to develop an improved voluntary closing, body-powered hand prosthesis. Five commercially available voluntary closing terminal devices were mechanically tested: three hands [Hosmer APRL VC hand, Hosmer Soft VC Male hand, Otto Bock 8K24] and two hooks [Hosmer APRL VC hook, TRS Grip 2S]. The test results serve as a design guideline for future prostheses. A test bench was used to measure activation cable forces and displacements, and the produced pinch forces. The measurements show that the hands require higher activation forces than the hooks and 1.5–8 times more mechanical work. The TRS hook requires the smallest activation force (33 N for a 15 N pinch force) and has the lowest energy dissipation (52 Nmm). The Hosmer Soft hand requires the largest activation force (131 N for a 15 N pinch force) and has the highest energy dissipation (1409 Nmm). The main recommendations for future prostheses are the following: (1) Required activation forces should be below the critical muscle force (∼ 18% of maximum), to enable continuous activation without muscle fatigue; and (2) hysteresis of mechanism and glove should be lowered, to increase efficiency and controllability.

Minimization of Muscle Fatigue as the Criterion to Solve Muscle Forces-Sharing Problem

2015 ◽  
Author(s):  
Reza Sharif Razavian ◽  
John McPhee
Keyword(s):  
Mathematical Model ◽  
Optimal Control ◽  
Muscle Fatigue ◽  
Prolonged Exercise ◽  
Muscle Force ◽  
Human Motion ◽  
Time Dependent ◽  
Force Sharing ◽  
Co Activation ◽  
Research Goal

The application of functional electrical stimulation (FES) to muscles quickly fatigues them. Our research goal is to determine the optimal control of FES signals that delay the fatigue for as long as possible. In this research we have used a physiology-based mathematical model of muscle fatigue, to study the behaviour of a musculoskeletal system during a prolonged exercise. To solve the redundant problem of muscle force sharing, we have used a time-dependent fatigue minimization objective instead of the usual activation-based minimization criteria. Our results showed that muscle co-activation, as seen in natural human motion, does not necessarily minimize muscle fatigue.

Spinal and Supraspinal Factors in Human Muscle Fatigue

2001 ◽  
Vol 81 (4) ◽  
pp. 1725-1789 ◽  
Author(s):  
S. C. Gandevia
Keyword(s):  
Muscle Fatigue ◽  
Muscle Force ◽  
Cortical Excitability ◽  
Central Fatigue ◽  
Muscle Afferents ◽  
Human Muscle ◽  
Voluntary Activation ◽  
Group Iii ◽  
Exercise Induced ◽  
Human Muscle Fatigue

Muscle fatigue is an exercise-induced reduction in maximal voluntary muscle force. It may arise not only because of peripheral changes at the level of the muscle, but also because the central nervous system fails to drive the motoneurons adequately. Evidence for “central” fatigue and the neural mechanisms underlying it are reviewed, together with its terminology and the methods used to reveal it. Much data suggest that voluntary activation of human motoneurons and muscle fibers is suboptimal and thus maximal voluntary force is commonly less than true maximal force. Hence, maximal voluntary strength can often be below true maximal muscle force. The technique of twitch interpolation has helped to reveal the changes in drive to motoneurons during fatigue. Voluntary activation usually diminishes during maximal voluntary isometric tasks, that is central fatigue develops, and motor unit firing rates decline. Transcranial magnetic stimulation over the motor cortex during fatiguing exercise has revealed focal changes in cortical excitability and inhibitability based on electromyographic (EMG) recordings, and a decline in supraspinal “drive” based on force recordings. Some of the changes in motor cortical behavior can be dissociated from the development of this “supraspinal” fatigue. Central changes also occur at a spinal level due to the altered input from muscle spindle, tendon organ, and group III and IV muscle afferents innervating the fatiguing muscle. Some intrinsic adaptive properties of the motoneurons help to minimize fatigue. A number of other central changes occur during fatigue and affect, for example, proprioception, tremor, and postural control. Human muscle fatigue does not simply reside in the muscle.

The Effect of Muscle Fatigue on Muscle Force-Couple Activation of the Shoulder

2001 ◽  
Vol 10 (4) ◽  
pp. 246-256 ◽  
Author(s):  
Timothy J. Henry ◽  
Scott M. Lephart ◽  
Jorge Giraldo ◽  
David Stone ◽  
Freddie H. Fu
Keyword(s):  
Muscle Fatigue ◽  
Outcome Measures ◽  
Muscle Force ◽  
Glenohumeral Joint ◽  
Previous History ◽  
Type Design ◽  
Before And After ◽  
History Of ◽  
Male Subjects ◽  
Force Couple

Context:Muscle fatigue is an important concept in regard to the muscle function of the shoulder joint. Its effect on the muscle force couples of the glenohumeral joint has not been fully identified.Objective:To examine the effects of muscle fatigue on muscle force-couple activation in the normal shoulder.Design:Pretest, posttest.Patients:Ten male subjects, age 18–30 years, with no previous history of shoulder problems.Main Outcome Measures:EMG (area) values were assessed for the anterior and middle deltoid, subscapularis, and infraspinatus muscles during 4 dynamic stabilizing exercises before and after muscle fatigue. The exercises examined were a push-up, horizontal abduction, segmental stabilization, and rotational movement on a slide board.Results:No significant differences were observed for any of the muscles tested.Conclusions:The results of our study indicate that force-couple coactivation of the glenohumeral joint is not significantly altered after muscle fatigue.

Resting Membrane Potential of Rat Plantaris Muscle Fibers After Prolonged Indirect Stimulation in Situ: Effect of Glucose Infusion

2005 ◽  
Vol 30 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Antony D. Karelis ◽  
François Péronnet ◽  
Phillip F. Gardiner
Keyword(s):  
Membrane Potential ◽  
Muscle Fatigue ◽  
Muscle Force ◽  
Recovery Period ◽  
Glucose Infusion ◽  
Resting Membrane Potential ◽  
Plantaris Muscle ◽  
M Wave ◽  
Elevated Glucose

The purpose of this study was to determine whether glucose infusion during prolonged indirect muscle stimulation (50 Hz for 200 ms every 2.7 s at 5 V) would have an effect on resting membrane potential (BMP). The BMP measured at Min 1 in the recovery period following stimulation of the rat plantaris muscle for 60 min in situ was significantly decreased in control rats, but was back to baseline values within 2 min. When glucose was infused ([glucose] ∼10 mM), no change was observed in RMP, and muscle fatigue and the reduction in M-wave peak-to-peak amplitude were both attenuated. However, muscle force and the electrical properties of the membrane were deteriorated both in rats infused with glucose and in control rats at Min 2 during the recovery period, at a time when RMP was not modified. These observations suggest that the effect of increased circulating glucose on fatigue-associated reductions in muscle fiber RMP seems to be modest and short-lived. Therefore, the attenuating effect of elevated glucose on muscle fatigue responses could be through mechanisms other than those associated with maintenance of RMP during fatigue. Key words: Na+/K+ pump, muscle fatigue, muscle force, M-wave, contractility

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