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Progress in Biophysics and Molecular... Jul 2022The article by Andrew Huxley in this journal in 1957, "Muscle Structure and theories of Contraction" is much more than a standard review of a field. It is itself a major...
The article by Andrew Huxley in this journal in 1957, "Muscle Structure and theories of Contraction" is much more than a standard review of a field. It is itself a major theoretical modelling achievement: the first mathematical model of the contractile process in skeletal muscle. That model was based on careful microscopic analysis of the striation patterns in skeletal muscles. Cited 4456 times, it holds the record for this journal.
Topics: Biophysical Phenomena; Biophysics; Models, Biological; Models, Theoretical; Muscle Contraction; Muscle, Skeletal
PubMed: 35381233
DOI: 10.1016/j.pbiomolbio.2022.03.007 -
Canadian Journal of Physiology and... Aug 2003Over the last decade, we have attempted to determine if mammalian skeletal muscle's steady-level force development as established by mechanical and stimulation... (Review)
Review
Over the last decade, we have attempted to determine if mammalian skeletal muscle's steady-level force development as established by mechanical and stimulation parameters can be increased or decreased by physiological signals. In these experiments, nitric oxide (NO), endothelin-1 (ET-1), adenosine (Ado), and beta-adrenergic agonists (beta) modified force production in the soleus and (or) the extensor digitorum longus (EDL) of the mouse. NO and beta increased the force produced by 0.5-s tetanic contractions at 0.6 contractions/min in both muscles. While EDL did not respond to either Ado or ET-1, the developed force of the soleus was amplified by Ado but attenuated by ET-1. Increased cAMP analogue concentrations amplified developed force in both muscles, but a cGMP analogue had no effect on either muscle. Following an increase in the contraction frequency of the soleus, the increased force in response to NO disappeared, as did the decreased force to ET-1. The increase in force due to a cAMP analogue disappeared during fatigue but reappeared quickly during recovery. Thus, steady-level developed force can be modified by a number of substances that can be released from locations in the body or muscle. The response to a given compound is determined by a complex interaction of metabolic and intracellular signals on the force-generating cascade.
Topics: Adrenergic beta-Agonists; Animals; Humans; Muscle Contraction; Muscle, Skeletal; Nitric Oxide
PubMed: 12897803
DOI: 10.1139/y03-031 -
Asian Journal of Surgery Feb 2023
Topics: Humans; Muscle Contraction; Hand; Foot; Lower Extremity; Muscle, Skeletal
PubMed: 35953369
DOI: 10.1016/j.asjsur.2022.07.048 -
Japanese Journal of Pharmacology 1992
Review
Topics: Animals; Muscle Contraction; Muscle, Smooth, Vascular; Receptors, Adrenergic, alpha; Signal Transduction
PubMed: 1324334
DOI: No ID Found -
Journal of Strength and Conditioning... Apr 2022
Topics: Humans; Isometric Contraction; Knee; Knee Joint; Muscle Contraction; Muscle Fatigue; Muscle, Skeletal; Muscles
PubMed: 32168176
DOI: 10.1519/JSC.0000000000003562 -
Experimental Physiology Sep 1994
Review
Topics: Animals; Isometric Contraction; Muscle Contraction; Muscle, Skeletal; Sarcomeres
PubMed: 7818869
DOI: 10.1113/expphysiol.1994.sp003811 -
Sensors (Basel, Switzerland) Sep 2014Skeletal muscle is the largest tissue structure in our body and plays an essential role for producing motion through integrated action with bones, tendons, ligaments and...
Skeletal muscle is the largest tissue structure in our body and plays an essential role for producing motion through integrated action with bones, tendons, ligaments and joints, for stabilizing body position, for generation of heat through cell respiration and for blood glucose disposal. A key function of skeletal muscle is force generation. Non-invasive and selective measurement of muscle contraction force in the field and in clinical settings has always been challenging. The aim of our work has been to develop a sensor that can overcome these difficulties and therefore enable measurement of muscle force during different contraction conditions. In this study, we tested the mechanical properties of a "Muscle Contraction" (MC) sensor during isometric muscle contraction in different length/tension conditions. The MC sensor is attached so that it indents the skin overlying a muscle group and detects varying degrees of tension during muscular contraction. We compared MC sensor readings over the biceps brachii (BB) muscle to dynamometric measurements of force of elbow flexion, together with recordings of surface EMG signal of BB during isometric contractions at 15° and 90° of elbow flexion. Statistical correlation between MC signal and force was very high at 15° (r = 0.976) and 90° (r = 0.966) across the complete time domain. Normalized SD or σN = σ/max(FMC) was used as a measure of linearity of MC signal and elbow flexion force in dynamic conditions. The average was 8.24% for an elbow angle of 90° and 10.01% for an elbow of angle 15°, which indicates high linearity and good dynamic properties of MC sensor signal when compared to elbow flexion force. The next step of testing MC sensor potential will be to measure tension of muscle-tendon complex in conditions when length and tension change simultaneously during human motion.
Topics: Biosensing Techniques; Humans; Isometric Contraction; Muscle Contraction; Muscle Tonus
PubMed: 25256114
DOI: 10.3390/s140917848 -
Biomedical Engineering Online Jul 2022Advances in sports medicine, rehabilitation applications and diagnostics of neuromuscular disorders are based on the analysis of skeletal muscle contractions. Recently,...
BACKGROUND
Advances in sports medicine, rehabilitation applications and diagnostics of neuromuscular disorders are based on the analysis of skeletal muscle contractions. Recently, medical imaging techniques have transformed the study of muscle contractions, by allowing identification of individual motor units' activity, within the whole studied muscle. However, appropriate image-based simulation models, which would assist the continued development of these new imaging methods are missing. This is mainly due to a lack of models that describe the complex interaction between tissues within a muscle and its surroundings, e.g., muscle fibres, fascia, vasculature, bone, skin, and subcutaneous fat. Herein, we propose a new approach to overcome this limitation.
METHODS
In this work, we propose to use deep learning to model the authentic intra-muscular skeletal muscle contraction pattern using domain-to-domain translation between in silico (simulated) and in vivo (experimental) image sequences of skeletal muscle contraction dynamics. For this purpose, the 3D cycle generative adversarial network (cycleGAN) models were evaluated on several hyperparameter settings and modifications. The results show that there were large differences between the spatial features of in silico and in vivo data, and that a model could be trained to generate authentic spatio-temporal features similar to those obtained from in vivo experimental data. In addition, we used difference maps between input and output of the trained model generator to study the translated characteristics of in vivo data.
RESULTS
This work provides a model to generate authentic intra-muscular skeletal muscle contraction dynamics that could be used to gain further and much needed physiological and pathological insights and assess and overcome limitations within the newly developed research field of neuromuscular imaging.
Topics: Computer Simulation; Image Processing, Computer-Assisted; Muscle Contraction
PubMed: 35804415
DOI: 10.1186/s12938-022-01016-4 -
Basic Research in Cardiology 1991Recent development of an experimental protocol to determine kinetics of active cross-bridge turnover is muscle allows analysis of possible Ca+(+)-effects on cross-bridge... (Comparative Study)
Comparative Study Review
A new concept for the mechanism of Ca+(+)-regulation of muscle contraction. Implications for physiological and pharmacological approaches to modulate contractile function of myocardium.
Recent development of an experimental protocol to determine kinetics of active cross-bridge turnover is muscle allows analysis of possible Ca+(+)-effects on cross-bridge turnover kinetics. This analysis enabled us to distinguish the two main hypotheses about the mechanism of regulation of muscle contraction. In the first hypothesis, the number of actively turning over cross-bridges is changed, while cross-bridge turnover kinetics are unaffected by Ca++ (regulation by "cross-bridge recruitment"). In the other hypotheses, cross-bridge turnover kinetics are controlled by Ca++, while the number of actively turning over cross-bridges is essentially unaffected (regulation by "rate modulation"). It is found that the major mechanism of regulation of muscle contraction is by a change in the rate constant (fapp) that determines the transition of a cross-bridge from the weak-binding (non-force generating) configuration to its strong-binding (force generating) configuration. It is demonstrated that the concept of "rate modulation" requires reinterpretation of force-pCa relations and of the mechanisms of physiological and pharmacological modulation of force-pCa relations. On this basis, an additional mechanism for positive inotropic interventions is demonstrated which may have advantages over the previously established mechanisms.
Topics: Animals; Calcium; Muscle Contraction; Muscles; Myocardial Contraction; Rabbits; Ranidae
PubMed: 1781769
DOI: 10.1007/978-3-662-30769-4_8 -
Pain Aug 1991
Topics: Headache; Humans; Muscle Contraction
PubMed: 1749635
DOI: 10.1016/0304-3959(91)90065-6