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Experimental Cell Research Nov 2010Skeletal muscles cope with a large range of activities, from being able to support the body weight during long periods of upright standing to perform explosive movements... (Review)
Review
Skeletal muscles cope with a large range of activities, from being able to support the body weight during long periods of upright standing to perform explosive movements in response to an unexpected threat. This requires systems for energy metabolism that can provide energy during long periods of moderately increased energy consumption as well as being able to rapidly increasing the rate of energy production more than 100-fold in response to explosive contractions. In this short review we discuss how muscles can deal with these divergent demands. We first outline the major energy metabolism pathways in skeletal muscle. Next we describe metabolic differences between different muscle fiber types. Contractile performance declines during intense activation, i.e. fatigue develops, and we discuss likely underlying mechanisms. Finally, we discuss the ability of muscle fibers to adapt to altered demands, and mechanisms behind these adaptations. The accumulated experimental evidence forces us to conclude that most aspects of energy metabolism involve multiple and overlapping signaling pathways, which indicates that the control of energy metabolism is too important to depend on one single molecule or mechanism.
Topics: Adaptation, Physiological; Animals; Energy Metabolism; Humans; Muscle Fatigue; Muscle Fibers, Skeletal; Muscle, Skeletal
PubMed: 20580710
DOI: 10.1016/j.yexcr.2010.05.019 -
Zhongguo Yi Liao Qi Xie Za Zhi =... May 2023Based on the joint analysis of EMG spectrum and amplitude method (JASA), a study on muscle fatigue assessment of spinal surgical instruments based on surface EMG signals...
Based on the joint analysis of EMG spectrum and amplitude method (JASA), a study on muscle fatigue assessment of spinal surgical instruments based on surface EMG signals was carried out, and a comparative evaluation of the operating comfort before and after the optimization of spinal surgical instruments was completed. A total of 17 subjects were recruited to collect the surface EMG signals of their brachioradialis and biceps. Five surgical instruments before and after optimization were selected for data comparison, and the operating fatigue time proportion of each group of instruments under the same task was calculated based on the RMS and MF eigenvalues. The results showed that when completing the same operation task, the operation fatigue time of the surgical instruments before optimization was significantly higher than that after optimization (<0.05); there was no significant difference in the fatigue status of brachioradialis and biceps when operating the same instrument (>0.05). These results provide objective data and reference for the ergonomic design of surgical instruments and fatigue damage protection.
Topics: Humans; Muscle Fatigue; Muscle, Skeletal; Electromyography; Ergonomics
PubMed: 37288623
DOI: 10.3969/j.issn.1671-7104.2023.03.004 -
Computer Methods in Biomechanics and... Feb 2022In this study, an attempt has been made to develop an automated muscle fatigue detection system using cyclostationary based geometric features of surface...
In this study, an attempt has been made to develop an automated muscle fatigue detection system using cyclostationary based geometric features of surface electromyography (sEMG) signals. For this purpose, signals are acquired from fifty-eight healthy volunteers under dynamic muscle fatiguing contractions. The sEMG signals are preprocessed and the epochs of signals under nonfatigue and fatigue conditions are considered for the analysis. A computationally effective Fast Fourier transform based accumulation algorithm is adapted to compute the spectral correlation density coefficients. The boundary of spectral density coefficients in the complex plane is obtained using alpha shape method. The geometric features, namely, perimeter, area, circularity, bending energy, eccentricity and inertia are extracted from the shape and the machine learning models based on multilayer perceptron (MLP) and extreme learning machine (ELM) are developed using these biomarkers. The results show that the cyclostationarity increases in fatigue condition. All the extracted features are found to have significant difference in the two conditions. It is found that the ELM model based on prominent features classifies the sEMG signals with a maximum accuracy of 94.09% and F-score of 93.75%. Therefore, the proposed approach appears to be useful for analysing the fatiguing contractions in neuromuscular conditions.
Topics: Algorithms; Electromyography; Fourier Analysis; Humans; Muscle Contraction; Muscle Fatigue; Muscle, Skeletal
PubMed: 34289775
DOI: 10.1080/10255842.2021.1955104 -
Experimental Physiology Mar 2023What is the central question of this study? What are the physiological mechanisms underlying muscle fatigue and the increase in the O cost per unit of work during...
NEW FINDINGS
What is the central question of this study? What are the physiological mechanisms underlying muscle fatigue and the increase in the O cost per unit of work during high-intensity exercise? What is the main finding and its importance? Muscle fatigue happens before, and does not explain, the slow component ( ), but they share the same origin. Muscle activation heterogeneity is associated with muscle fatigue and . Knowing this may improve training prescriptions for healthy people leading to improved public health outcomes.
ABSTRACT
This study aimed to explain the slow component ( ) and muscle fatigue during cycling at different intensities. The muscle fatigue of 16 participants was determined through maximal isokinetic effort lasting 3 s during constant work rate bouts of moderate (MOD), heavy (HVY) and very heavy intensity (VHI) exercise. Breath-by-breath , near-infrared spectroscopy signals and EMG activity were analysed (thigh muscles). was higher during VHI exercise (∼70% vs. ∼28% of reserve in HVY). The deoxygenated haemoglobin final value during VHI exercise was higher than during HVY and MOD exercise (∼90% of HHb physiological normalization, vs. ∼82% HVY and ∼45% MOD). The muscle fatigue was greater after VHI exercise (∼22% vs. HVY ∼5%). There was no muscle fatigue after MOD exercise. The greatest magnitude of muscle fatigue occurred within 2 min (VHI ∼17%; HVY ∼9%), after which it stabilized. No significant relationship between and muscle force production was observed. The τ of muscle was significantly related (R = 0.47) with torque decrease for VHI. Type I and II muscle fibre recruitment mainly in the rectus femoris moderately explained the muscle fatigue (R = 0.30 and 0.31, respectively) and the (R = 0.39 and 0.27, respectively). The is also partially explained by blood lactate accumulation (R = 0.42). In conclusion muscle fatigue and O cost seem to share the same physiological cause linked with a decrease in the muscle and a change in lactate accumulation. Muscle fatigue and are associated with muscle activation heterogeneity and metabolism of different muscles activated during cycling.
Topics: Humans; Oxygen; Muscle, Skeletal; Muscle Fatigue; Energy Metabolism; Lactates; Oxygen Consumption
PubMed: 36648072
DOI: 10.1113/EP090444 -
International Journal of Environmental... Jun 2022Purpose: To evaluate the long-term effect of vibration therapy with holistic and local intervention in treating muscle fatigue in elite athletes during their intensive...
Purpose: To evaluate the long-term effect of vibration therapy with holistic and local intervention in treating muscle fatigue in elite athletes during their intensive training season. Methods: Study participants included five male athletes from a provincial Greco-Roman wrestling team who were qualified for the finals of China’s national games. During the study, conventional therapeutic intervention was applied during the initial three weeks of the study, and an instrument intervention was adopted in the following three weeks. A surface electromyography (sEMG) was used to measure muscle fatigue of latissimus dorsi, both before and after each intervention session. Specifically, the pre-intervention measurement was conducted right after the daily training completion; and the post-intervention measurement occurred in the following morning. The data analyses were to compare the differences in the muscle fatigue data between the two modes of interventions, conventional and instrument therapy. Results: The conventional intervention showed no significant difference in the sEMG indexes before and after the intervention; while for the instrument intervention, the pre- and post- intervention sEMG indexes differed significantly (p < 0.05). Conclusion: The long-term effects of instrument vibration therapy on muscle fatigue recovery were studied based on observational data from elite athletes. The results indicate that the vibration therapy with holistic and local consideration demonstrated an effective reduction of muscle fatigue and/or fatigue accumulation in elite athletes during their intensive training season.
Topics: Athletes; Electromyography; Humans; Male; Muscle Fatigue; Vibration; Wrestling
PubMed: 35742794
DOI: 10.3390/ijerph19127531 -
Medical Engineering & Physics Dec 2017We propose a force estimation method in fatigue condition using a muscle-twitch model and surface electromyography (sEMG). The twitch model, which is an estimate of...
We propose a force estimation method in fatigue condition using a muscle-twitch model and surface electromyography (sEMG). The twitch model, which is an estimate of force by a single spike, was obtained from sEMG features and measured forces. Nine healthy subjects performed isometric index finger abduction until exhaustion for a series of dynamic contractions (0-20% MVC) to characterize the twitch model and static contractions (50% MVC) to induce muscle fatigue. Muscle fatigue was identified based on the changes of twitch model; the twitch peak decreased and the contraction time increased as muscle fatigue developed. Force estimation performance in non-fatigue and fatigue conditions was evaluated and its results were compared with that of a conventional method using the mean absolute value (MAV). In non-fatigue conditions, the performance of the proposed method (0.90 ± 0.05) and the MAV method (0.88 ± 0.06) were comparable. In fatigue conditions, the performance was significantly improved for the proposed method (0.87 ± 0.05) compared with the MAV (0.78 ± 0.09).
Topics: Adult; Biomechanical Phenomena; Female; Fingers; Healthy Volunteers; Humans; Isometric Contraction; Male; Mechanical Phenomena; Models, Biological; Muscle Fatigue
PubMed: 29054339
DOI: 10.1016/j.medengphy.2017.10.002 -
Biomechanics and Modeling in... Apr 2017A novel technique is proposed to predict force reduction in skeletal muscle due to fatigue under the influence of electrical stimulus parameters and muscle physiological...
A novel technique is proposed to predict force reduction in skeletal muscle due to fatigue under the influence of electrical stimulus parameters and muscle physiological characteristics. Twelve New Zealand white rabbits were divided in four groups ([Formula: see text]) to obtain the active force evolution of in vitro Extensor Digitorum Longus muscles for an hour of repeated contractions under different electrical stimulation patterns. Left and right muscles were tested, and a total of 24 samples were used to construct a response surface based in the proper generalized decomposition. After the response surface development, one additional rabbit was used to check the predictive potential of the technique. This multidimensional surface takes into account not only the decay of the maximum repeated peak force, but also the shape evolution of each contraction, muscle weight, electrical input signal and stimulation protocol. This new approach of the fatigue simulation challenge allows to predict, inside the multispace surface generated, the muscle response considering other stimulation patterns, different tissue weight, etc.
Topics: Animals; Electric Stimulation; Models, Biological; Muscle Contraction; Muscle Fatigue; Muscle, Skeletal; Rabbits; Time Factors
PubMed: 27714474
DOI: 10.1007/s10237-016-0841-y -
IEEE Transactions on Neural Networks... Aug 2023Muscle fatigue detection is of great significance to human physiological activities, but many complex factors increase the difficulty of this task. In this article, we...
Muscle fatigue detection is of great significance to human physiological activities, but many complex factors increase the difficulty of this task. In this article, we integrate several effective techniques to distinguish muscle states under fatigue and nonfatigue conditions via surface electromyography (sEMG) signals. First, we perform an isometric contraction experiment of biceps brachii to collect sEMG signals. Second, we propose a neural architecture search (NAS) framework based on reinforcement learning to autogenerate neural networks. Finally, we present an effective two-step training strategy to improve the performance by combining CNN with three types of commonly used statistical algorithms. Meanwhile, we propose a data enhancement algorithm based on empirical mode decomposition (EMD) to generate time-series data for expanding the dataset. The results show that this search algorithm can hunt for high-performing networks, and the accuracy of the best-selected model combined with support vector machine (SVM) for the group is 96.5%. With the same architecture, the average accuracy in individual models is 97.8%. The proposed data enhancement technique can effectively improve the fatigue detection performance, which allows further implementations in the human-exoskeleton interaction systems.
Topics: Humans; Muscle Fatigue; Electromyography; Neural Networks, Computer; Muscle, Skeletal; Isometric Contraction; Algorithms
PubMed: 34752412
DOI: 10.1109/TNNLS.2021.3124330 -
Biomedizinische Technik. Biomedical... Aug 2019Repetitive electrically-evoked muscle contraction leads to accelerated muscle fatigue. This study assessed electrically-evoked fatiguing muscle with changes to...
Repetitive electrically-evoked muscle contraction leads to accelerated muscle fatigue. This study assessed electrically-evoked fatiguing muscle with changes to mechanomyography root mean square percentage (%RMS-MMG) and tissue saturation index (%TSI) in extensor carpi radialis. Forty healthy volunteers (n=40) performed repetitive electrical-evoked wrist extension to fatigue and results were analyzed pre- and post-fatigue, i.e. 50% power output (%PO) drop. Responses of %PO, %TSI and %RMS-MMG were correlated while the relationships between %RMS-MMG and %TSI were investigated using linear regression. The %TSI for both groups were negatively correlated with declining %PO as the ability of the muscle to take up oxygen became limited due to fatigued muscle. The %RMS-MMG behaved in two different patterns post-fatigue against declining %PO whereby; (i) group A showed positive correlation (%RMS-MMG decreased) throughout the session and (ii) group B demonstrated negative correlation (%RMS-MMG increased) with declining %PO until the end of the session. Regression analysis showed %TSI was inversely proportional to %RMS-MMG during post-fatigue in group A. Small gradients in both groups suggested that %TSI was not sensitive to the changes in %RMS-MMG and they were mutually exclusive. Most correlation and regression changed significantly post-fatigue indicating that after fatigue, the condition of muscle had changed mechanically and physiologically.
Topics: Humans; Motion; Muscle Contraction; Muscle Fatigue; Muscle, Skeletal; Spectroscopy, Near-Infrared; Wrist Joint
PubMed: 30231006
DOI: 10.1515/bmt-2018-0058 -
Advances in Experimental Medicine and... 1995The following is a brief review of the intrinsic properties of motoneurons that contribute to their recruitment and rate modulation. Our emphasis is on properties that... (Review)
Review
The following is a brief review of the intrinsic properties of motoneurons that contribute to their recruitment and rate modulation. Our emphasis is on properties that may either accelerate or delay the onset of muscular fatigue. In general, intrinsic motoneuron properties are regulated in a way that minimizes energy expenditure. The correlation of recruitment threshold with motoneuron type ensures that the most fatigable motor units are reserved for the most forceful contractions. The variation in minimum firing rates arising from variations in AHP characteristics ensures that motoneurons begin to fire at rates that are matched to the force producing characteristics of their muscle units. Further, it is possible that spike-frequency adaptation contributes to optimization of the tension (force)-firing frequency (T-f) transform of individual motor units.
Topics: Animals; Membrane Potentials; Motor Neurons; Muscle Fatigue
PubMed: 8585445
DOI: No ID Found