DOCSLIB.ORG

Muscle Fatigue R. H. T. EDWARDS B.Sc., Ph.D., M.B., M.R.C.P

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Muscle Fatigue R. H. T. EDWARDS B.Sc., Ph.D., M.B., M.R.C.P Postgrad Med J: first published as 10.1136/pgmj.51.593.137 on 1 March 1975. Downloaded from Postgraduate Medical Journal (March 1975) 51, 137-143. Muscle fatigue R. H. T. EDWARDS B.Sc., Ph.D., M.B., M.R.C.P. Royal Postgraduate Medical School, Hammersmith Hospital, Du Cane Road, London Summary Muscle fatigue is a common symptom but there are no universally accepted methods for quantitating the function of voluntary muscle. This paper describes three main methods ofassessment: simple clinical tests of muscle function; thermal probe measurements of metabolic heat production during muscular contrac- tion; needle biopsy studies of muscle structure and chemistry. These methods, though at a relatively early stage of development, have given promising results which suggest that they could be useful in assessing pos- sible new forms of treatment in patients with neuro- muscular disorders. Protected by copyright. A SKELETAL muscle is said to be fatigued when it fails FIG. 1. Simple diagram of physiological and psycho- to sustain the required force. The mechanisms con- physical feedback mechanisms controlling muscular trolling the force of contraction in man involve contraction. several interrelated physiological and psychophysical feedback control mechanisms (Fig. 1). The system comparisons to be made on separate occasions by of weakness and fatigue would seem likely in some the same observer or by different observers. A simple way to stem from disturbances in these complex quantitative test, which might be included in the mechanisms. The physiology of fatigue has been clinical examination,- is to time how long the patient studied at various levels of organization in animal when lying supine can hold one leg at 450 above the muscle preparations (reviewed in Simonson, 1971) couch. Normal subjects vary widely in the time they but there have been few advances which would allow can do this but the lower limits found in 150 men a systematic investigation of human weakness and and 150 women by Fessel, Taylor and Johnson (1970) fatigue. Electromyography and allied electrophysio- were 60 sec for the men and 30 sec for the women. http://pmj.bmj.com/ logical techniques play an increasingly important A similar test, studied by the same authors, is to role in the clinical diagnosis of neuromuscular dis- time how long the head can be held off the couch, orders (Desmedt, 1973) but still the evaluation is to a when the subject is lying supine. Lower normal limits large extent qualitative since quantitative EMG tech- found in the same populations were 90 sec for the niques, though potentially valuable, are still in their men and 30 sec for the women. infancy. Voluntary, muscle power can now be quantitated The assessment of weakness and fatigue by in the course of the the usual examination of the neuro- on September 23, 2021 by guest. usual clinical examination of the neuromuscular muscular system with a new hand-held clinical system is difficult unless changes are gross. The dynamometer (Edwards and McDonnell, 1974). Medical Research Council grading scale for classify- This instrument ('The Hammersmith Myometer') ing muscular contraction has been widely used since fits into the palm of the examiner's hand and registers its introduction during the Second World War the maximum force exerted on the patient's limb (Medical Research Council, 1943). This scale, though when a resisted movement is overcome. Clearly the valuable for describing large changes, does not give force recorded depends on the mechanics of the a sufficiently objective assessment to allow precise muscle and lever systems operating. The myometer has to be applied to specified anatomical sites for Based on a British Postgraduate Medical Federation measurements to 'Scientific Basis of Medicine' Lecture, 1974. be consistent. This instrument is Correspondence: Dr R. H. T. Edwards, Royal Post- potentially as useful an addition to the physicians' graduate Medical School, Hammersmith Hospital, Du Cane examination equipment as the sphygmomanometer Road, London W12 OHS. and peak flow meter. Simple quantitative tests of 138 R. H. T. Edwards Postgrad Med J: first published as 10.1136/pgmj.51.593.137 on 1 March 1975. Downloaded from muscle function are likely to become more important ankle when the knee is flexed to a right angle (Torn- in the future since there is increasing emphasis on vall, 1963). Intramuscular pressure rises and occludes physiotherapeutic methods in rehabilitation and the the muscle circulation at forces greater than 20 % of promise of effective treatment of a number of a maximum voluntary contraction (Barcroft and locomotor disorders as a result of recent advances Millen, 1939; Edwards, Hill and McDonnell, 1972). in neuropharmacology. This means that the energy for sustaining a long sub- Such simple clinical tests can never elucidate the maximal contraction must be almost entirely supplied cause of fatigue. Moreover the measurement of from anaerobic sources (Table 1). Since no external voluntary contractions depends on the co-operation work is done in this type of contraction, all the of the patient. The new approaches that I havesought chemically stored energy which is exchanged during to develop with my colleagues Dr D. K. Hill, F.R.S., muscular activity has to appear as heat, which in the Dr D. A. Jones and Mrs Caroline Maunder at the absence ofblood flow is largely retained in the muscle. Royal Postgraduate Medical School are designed to The quadriceps muscle thus behaves as a 'closed overcome these problems and to break into the system' when it contracts isometrically and this pro- complex ofinterrelated servo-controls by establishing vides a valuable experimental model for studying objective measurements of the metabolic activity of muscular contraction in man. Force is measured the contracting muscle. Fortunately fatigue is a with a strain gauge, metabolic heat production is symptom (unlike angina) which can be experienced measured with a thermal probe (Edwards, McDon- under experimental conditions by healthy individuals nell and Hill, 1974b) and changes in muscle meta- (e.g. after muscular exercise). It has, therefore, been bolism are followed by chemical analysis of repeated possible to develop the approach by studies in healthy needle biopsy samples (Hultman, 1967; Karlsson, volunteers before seeking possible application for 1971; Edwards et al., 1972a; Ahlborg et al., 1972). the of with It study patients myopathies. is well known that the time an isometric contrac- Protected by copyright. First a suitable muscle must be chosen for the tion can be sustained depends on the force exerted. experimental studies. No muscle is ideal for this From a large number of observations in several purpose but the quadriceps has the advantages that muscles, Rohmert (1960) defined a curved relation it is an important muscle for physical activities in between endurance time and force (Fig. 2). Our everyday life, and it is affected to a greater or lesser results generally agree with Rohmert's, however, extent in many myopathies. Further advantages are some of our athletes had a greater capacity to sustain that the muscle (the vastus lateralis fraction of the contractions than our sedentary subjects, possibly quadriceps) is large enough and free of important because of superior motivation or because of meta- blood vessels and nerves to allow probes to be in- bolic adaptations in their muscles (Gollnick et al., serted and for small samples of muscle to be safely 1972). The subject's full co-operation is needed in taken by a needle biopsy technique (Bergstrom, establishing the correct value for the force of a 1962). maximal voluntary contraction (MVC), the standard In normal life a muscle may shorten, lengthen or by which all submaximal force measurements are may remain at constant length during contraction. compared. In well motivated normal subjects the http://pmj.bmj.com/ The first two forms of contraction are involved in MVC force is proportional to the body weight (Fig. rhythmic. ('dynamic') exercise, such as walking or 3). (Body weight was chosen as a standard not only cycling whereas the last ('isometric') form is impor- because muscular strength obviously varies with body tant in gripping or holding tasks. An isometric con- size but because thequadricepsmuscleplaysan impor- traction of the quadriceps is studied with the subject tant role in supporting a large part of the bodyweight seated in an adjustable chair. The pelvic girdle is ineverydaylifeactivities.) In patients there is likely to stabilized with a seat belt and the force of contrac- be uncertainty as to the validity of MVC measure- tion measured with a strain gauge attached to the ments and whether or not contractions have been on September 23, 2021 by guest. TABLE 1. Energy sources for muscular activity Short term (anaerobic) sources 1. Adenosine triphosphate (ATP) - adenosine diphosphate (ADP) + inorganic phosphate (Pi) + energy 2. Phosphorylcreatine + ADP creatine + ATP 3. Glycogen/glucose + Pi + ADP lactate + ATP Long term (aerobic) sources 1. Glycogen/glucose + ADP Pi+ -t02 H20 + CO2 + ATP 2. Free fatty acids + ADP + P, + 02 --- H20 + CO2 + ATP Muscle fatigue 139 Postgrad Med J: first published as 10.1136/pgmj.51.593.137 on 1 March 1975. Downloaded from I( 0 ._ cx f c c Refererence (all subjects) 20 40 60 80 Force as 0/0 maximum voluntary contraction 2. between force ofcontraction and endurance time FIG. Relationship Protected by copyright. for isometric contractions of the quadriceps muscle, sustained to fatigue. Symbols indicate results in individual subjects studied at Hammersmith. The curve, redrawn from Rohmert (1960) is based on measurements in thirteen different muscle groups, including the quadri- ceps. Sedentary males, 0 (n = 10); female subjects, * (n = 5); male athletes, 0 (n = 5); female athletes, A (n = 11). /+2s.d. 80 I/. 0% http://pmj.bmj.com/ Z 70 / 0 ,o0 0 u 60)F ~- 2 s.d. / 0 / 0 0 ' 50)- o0 / 0 OX : 40 0 / on September 23, 2021 by guest.
Load more

Recommended publications
  • Cellular Mechanisms of Muscle Fatigue
    PHYSIOLOGICAL REVIEWS Vol. ‘74, No. 1, January 1994 Printed in U.S.A. Cellular Mechanisms of Muscle Fatigue R. H. FITTS Department of Biology, Marquette University, Milwaukee, Wisconsin I. Introduction ......................................................................................... 49 A. Definition and current theories of fatigue ....................................................... 49 B. Muscle fiber type composition ................................................................... 50 C. Exercise intensity and environmental conditions ............................................... 51 II. Mechanical Properties ................................................................. .............. 51 A. Isometric contractile properties ................................................................. 52 B. Maximal shortening speed and peak power ..................................................... 55 III. Excitation-Contraction Coupling .................................................................... 55 A. Sarcolemma resting potential ................................................................... 55 B. Sarcolemma action potential .................................................................... 57 C. T tubular system ................................................................................. 58 D. T tubule-sarcoplasmic reticulum junction and calcium release from terminal cisternae ...... 60 IV. Lactic Acid, Intracellular pH, and Fatigue ......................................................... 62 A. Historical
    [Show full text]
  • Age-Specific Modulation of Intermuscular Beta Coherence
    www.nature.com/scientificreports OPEN Age‑specifc modulation of intermuscular beta coherence during gait before and after experimentally induced fatigue Paulo Cezar Rocha dos Santos1,2,5*, Claudine J. C. Lamoth1, Fabio Augusto Barbieri3, Inge Zijdewind4, Lilian Teresa Bucken Gobbi2 & Tibor Hortobágyi1 We examined the efects of age on intermuscular beta‑band (15–35 Hz) coherence during treadmill walking before and after experimentally induced fatigue. Older (n = 12) and younger (n = 12) adults walked on a treadmill at 1.2 m/s for 3 min before and after repetitive sit‑to‑stand, rSTS, to induce muscle fatigability. We measured stride outcomes and coherence from 100 steps in the dominant leg for the synergistic (biceps femoris (BF)‑semitendinosus, rectus femoris (RF)‑vastus lateralis (VL), gastrocnemius lateralis (GL)‑Soleus (SL), tibialis anterior (TA)‑peroneus longus (PL)) and for the antagonistic (RF‑BF and TA‑GL) muscle pairs at late swing and early stance. Older vs. younger adults had 43–62% lower GL‑SL, RF‑VL coherence in swing and TA‑PL and RF‑VL coherence in stance. After rSTS, RF‑BF coherence in late swing decreased by ~ 20% and TA‑PL increased by 16% independent of age (p = 0.02). Also, GL‑SL coherence decreased by ~ 23% and increased by ~ 23% in younger and older, respectively. Age afects the oscillatory coupling between synergistic muscle pairs, delivered presumably via corticospinal tracts, during treadmill walking. Muscle fatigability elicits age‑specifc changes in the common fuctuations in muscle activity, which could be interpreted as a compensation for muscle fatigability to maintain gait performance. Healthy aging modifes the integrated and coordinated neural control of gait1,2.
    [Show full text]
  • Muscle Physiology Dr
    Muscle Physiology Dr. Ebneshahidi Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Skeletal Muscle Figure 9.2 (a) Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Functions of the muscular system . 1. Locomotion . 2. Vasoconstriction and vasodilatation- constriction and dilation of blood vessel Walls are the results of smooth muscle contraction. 3. Peristalsis – wavelike motion along the digestive tract is produced by the Smooth muscle. 4. Cardiac motion . 5. Posture maintenance- contraction of skeletal muscles maintains body posture and muscle tone. 6. Heat generation – about 75% of ATP energy used in muscle contraction is released as heat. Copyright. © 2004 Pearson Education, Inc., publishing as Benjamin Cummings . Striation: only present in skeletal and cardiac muscles. Absent in smooth muscle. Nucleus: smooth and cardiac muscles are uninculcated (one nucleus per cell), skeletal muscle is multinucleated (several nuclei per cell ). Transverse tubule ( T tubule ): well developed in skeletal and cardiac muscles to transport calcium. Absent in smooth muscle. Intercalated disk: specialized intercellular junction that only occurs in cardiac muscle. Control: skeletal muscle is always under voluntary control‚ with some exceptions ( the tongue and pili arrector muscles in the dermis). smooth and cardiac muscles are under involuntary control. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Innervation: motor unit . a) a motor nerve and a myofibril from a neuromuscular junction where gap (called synapse) occurs between the two structures. at the end of motor nerve‚ neurotransmitter (i.e. acetylcholine) is stored in synaptic vesicles which will release the neurotransmitter using exocytosis upon the stimulation of a nerve impulse. Across the synapse the surface the of myofibril contains receptors that can bind with the neurotransmitter.
    [Show full text]
  • Age-Related Differences in Muscle Synergy Organization During Step
    applied sciences Article Age-Related Differences in Muscle Synergy Organization during Step Ascent at Different Heights and Directions Remco J. Baggen 1,2 , Jaap H. van Dieën 2 , Evelien Van Roie 1 , Sabine M. Verschueren 3, Georgios Giarmatzis 4, Christophe Delecluse 1 and Nadia Dominici 2,* 1 Department of Movement Sciences, Physical Activity, Sports and Health Research Group, KU Leuven, 3001 Leuven, Belgium 2 Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Institute for Brain and Behavior Amsterdam & Amsterdam Movement Sciences, 1081 BT Amsterdam, The Netherlands 3 Department of Rehabilitation Sciences, Research Group for Musculoskeletal Rehabilitation, KU Leuven, 3001 Leuven, Belgium 4 Department of Electrical and Computer Engineering, Visualization & Virtual Reality Group, University of Patras, 26504 Rio Achaia, Greece * Correspondence: [email protected]; Tel.: +31-20-59-88-591 Received: 30 January 2020; Accepted: 5 March 2020; Published: 14 March 2020 Abstract: The aim of this study was to explore the underlying age-related differences in dynamic motor control during different step ascent conditions using muscle synergy analysis. Eleven older women (67.0 y 2.5) and ten young women (22.5 y 1.6) performed stepping in forward and lateral directions ± ± at step heights of 10, 20 and 30 cm. Surface electromyography was obtained from 10 lower limb and torso muscles. Non-negative matrix factorization was used to identify sets of (n) synergies across age groups and stepping conditions. In addition, variance accounted for (VAF) by the detected number of synergies was compared to assess complexity of motor control. Finally, correlation coefficients of muscle weightings and between-subject variability of the temporal activation patterns were calculated and compared between age groups and stepping conditions.
    [Show full text]
  • A Comparative Study of Skeletal Muscle Fatigue in Diabetic and Non-Diabetic Human Beings
    National Journal of Physiology, Pharmacy and Pharmacology RESEARCH ARTICLE A comparative study of skeletal muscle fatigue in diabetic and non-diabetic human beings Yamini Devulapally1, Devender Singh Negi2, Kasturi Bai Pasula2 1Department of Physiology, SVS Medical College, Mahabubnagar, Telangana, India, 2Department of Physiology, MediCiti Institute of Medical Sciences, Medchal, Telangana, India Correspondence to: Yamini Devulapally, E-mail: [email protected] Received: July 13, 2018; Accepted: August 22, 2018 ABSTRACT Background: Diabetes mellitus has now emerged as a global cause of concern. Fatigue is a widespread and persistent complaint among diabetics. It is associated with a decreased ability to manage day to day activities. Muscles that are used intensively are more likely to get fatigued. Since the flexors of the fingers are used intensively even in an otherwise sedentary lifestyle, this group of muscles are assessed in this study. Aims and Objectives: The study was done to compare the skeletal muscle fatigue in non-diabetics and controlled diabetics. Materials and Methods: The study population consists of two groups of male participants in the age group of 30–40 years. The control group consists of 50 healthy volunteers. The test group consists of 50 controlled diabetics. Mosso’s ergography was done to assess the performance of flexors of the fingers of the non-dominant hand. Duration of onset of fatigue was noted. Work done was calculated. Windostat version 9.2 software was used for all statistical analysis. Comparison of variables between the two study groups was done using ANOVA. Results: The duration of onset of fatigue and work done was significantly higher (P < 0.005) in non-diabetics than diabetics.
    [Show full text]
  • Muscle Fatigue: General Understanding and Treatment
    OPEN Experimental & Molecular Medicine (2017) 49, e384; doi:10.1038/emm.2017.194 Official journal of the Korean Society for Biochemistry and Molecular Biology www.nature.com/emm REVIEW Muscle fatigue: general understanding and treatment Jing-jing Wan2, Zhen Qin2, Peng-yuan Wang, Yang Sun and Xia Liu Muscle fatigue is a common complaint in clinical practice. In humans, muscle fatigue can be defined as exercise-induced decrease in the ability to produce force. Here, to provide a general understanding and describe potential therapies for muscle fatigue, we summarize studies on muscle fatigue, including topics such as the sequence of events observed during force production, in vivo fatigue-site evaluation techniques, diagnostic markers and non-specific but effective treatments. Experimental & Molecular Medicine (2017) 49, e384; doi:10.1038/emm.2017.194; published online 6 October 2017 INTRODUCTION muscular and cardiovascular disorders, as well as aging and Fatigue is a common non-specific symptom experienced by frailty. This review primarily focuses on muscle fatigue, many people and is associated with many health conditions. particularly during intense exercise, to provide a basic under- Often defined as an overwhelming sense of tiredness, lack of standing and potential therapies for muscle fatigue. energy and feeling of exhaustion, fatigue relates to a difficulty in performing voluntary tasks.1 Fatigue accumulation, if not FACTORS THAT AFFECT MUSCLE CONTRACTION AND resolved, leads to overwork, chronic fatigue syndrome (CFS), FATIGUE overtraining syndrome, and even endocrine disorders, immu- The production of skeletal muscle force depends on contractile nity dysfunction, organic diseases and a threat to human mechanisms, and failure at any of the sites upstream of the health.
    [Show full text]
  • Muscle Cramps During Exercise V Is It Fatigue Or Electrolyte Deficit? Michael F
    SUPPLEMENT — SODIUM BALANCE AND EXERCISE Muscle Cramps during Exercise V Is It Fatigue or Electrolyte Deficit? Michael F. Bergeron National Institute for Youth Sports & Health at Sanford, Sanford USD Medical Center, Sioux Falls, SD BERGERON, M.F. Muscle cramps during exercise V is it fatigue or electrolyte deficit? Curr. Sports Med. Rep., Vol. 7, No. 4, pp. S50YS55, 2008. Skeletal muscle cramps during exercise are a common affliction, even in highly fit athletes. And as empirical evidence grows, it is becoming increasingly clear that there are two distinct and dissimilar general categories of exercise-associated muscle cramps. Skeletal muscle overload and fatigue can prompt muscle cramping locally in the overworked muscle fibers, and these cramps can be treated effectively with passive stretching and massage or by modifying the exercise intensity and load. In contrast, extensive sweating and a consequent significant whole-body exchangeable sodium deficit caused by insufficient dietary sodium intake to offset sweat sodium losses can lead to a contracted interstitial fluid compartment and more widespread skeletal muscle cramping, even when there is minimal or no muscle overload and fatigue. Signs of hyperexcitable neuromuscular junctions may appear first as fasciculations during breaks in activity, which eventually progress to more severe and debilitating muscle spasms. Notably, affected athletes often present with normal or somewhat elevated serum electrolyte levels, even if they are Bsalty sweaters,^ because of hypotonic sweat loss and a fall in intravascular volume. However, recovery and maintenance of water and sodium balance with oral or intravenous salt solutions is the proven effective strategy for resolving and averting exercise-associated muscle cramps that are prompted by extensive sweating and a sodium deficit.
    [Show full text]
  • Effect Stretching and Recovery on Delayed Onset Muscle Soreness (DOMS) After Exercise
    Journal of Physics: Conference Series PAPER • OPEN ACCESS Effect Stretching and Recovery on Delayed Onset Muscle Soreness (DOMS) After Exercise To cite this article: Zulaini et al 2021 J. Phys.: Conf. Ser. 1811 012113 View the article online for updates and enhancements. This content was downloaded from IP address 170.106.202.126 on 27/09/2021 at 08:37 ICOSTA 2020 IOP Publishing Journal of Physics: Conference Series 1811 (2021) 012113 doi:10.1088/1742-6596/1811/1/012113 Effect Stretching and Recovery on Delayed Onset Muscle Soreness (DOMS) After Exercise Zulaini1, N S Harahap1, N S Siregar1, Zulfahri1 1Department of Sports Sciences, Faculty of Sports Sciences, Universitas Negeri Medan, Medan, North Sumatra, Indonesia. *Corresponding author: [email protected] Abstract. DOMS (Delayed Onset Muscle Soreness) is pain that a person feels within 24-72 hours after doing sports activities, and recovery occurs within 4-6 days. Pain is caused by metabolic waste such as lactic acid in muscles and extracellular fluids, irritating the ends of the sensory fibers. An exercise that is not adequately controlled can cause muscle damage, inflammation, and muscle pain. Recovery should be made after each exercise that aims to eliminate lactic acid in muscles. The study aimed to see the effect of stretching and recovery on DOMS after physical activity. This research method is a quasi-experimental research design using a randomized pre and post-test group design. The subjects in this study were students of the Department of Sport Science, Medan State University, who assessed 16 people. The research subjects were randomly divided into two groups.
    [Show full text]
  • Pulmonary and Respiratory Muscle Function in Response to Marathon and Ultra-Marathon Running: a Review
    Pulmonary and respiratory muscle function in response to marathon and ultra-marathon running: a review. TILLER, Nicholas <http://orcid.org/0000-0001-8429-658X> Available from Sheffield Hallam University Research Archive (SHURA) at: http://shura.shu.ac.uk/24576/ This document is the author deposited version. You are advised to consult the publisher's version if you wish to cite from it. Published version TILLER, Nicholas (2019). Pulmonary and respiratory muscle function in response to marathon and ultra-marathon running: a review. Sports Medicine. Copyright and re-use policy See http://shura.shu.ac.uk/information.html Sheffield Hallam University Research Archive http://shura.shu.ac.uk Sports Medicine https://doi.org/10.1007/s40279-019-01105-w REVIEW ARTICLE Pulmonary and Respiratory Muscle Function in Response to Marathon and Ultra‑Marathon Running: A Review Nicholas B. Tiller1 © The Author(s) 2019 Abstract The physiological demands of marathon and ultra-marathon running are substantial, afecting multiple body systems. There have been several reviews on the physiological contraindications of participation; nevertheless, the respiratory implications have received relatively little attention. This paper provides an up-to-date review of the literature pertaining to acute pulmo- nary and respiratory muscle responses to marathon and ultra-marathon running. Pulmonary function was most commonly assessed using spirometry, with infrequent use of techniques including single-breath rebreathe and whole-body plethysmog- raphy. All studies observed statistically signifcant post-race reductions in one-or-more metrics of pulmonary function, with or without evidence of airway obstruction. Nevertheless, an independent analysis revealed that post-race values rarely fell below the lower-limit of normal and are unlikely, therefore, to be clinically signifcant.
    [Show full text]
  • Skeletal Muscle Weakness Often Occurs in Patients with Myalgic Encephalomyelitis / Chronic Fatigue Syndrome (ME/CFS)
    https://www.scientificarchives.com/journal/journal-of-experimental-neurology Journal of Experimental Neurology Commentary Skeletal Muscle Weakness Often Occurs in Patients with Myalgic Encephalomyelitis / Chronic Fatigue Syndrome (ME/CFS) Yves Jammes1,2, Frédérique Retornaz2* 1C2VN UMR Inra Inserm, Faculty of Medicine, Aix-Marseille University, France 2Department of Internal Medicine, European Hospital, Marseille, France *Correspondence should be addressed to Frédérique Retornaz; [email protected] Received date: April 16, 2020, Accepted date: May 14, 2020 Copyright: © 2020 Jammes Y, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Highlights • Altered muscle function often occurs in ME/CFS patients. • Reduced handgrip strength is proportional to lowered physical performance • Muscle fatigue could result from altered muscle excitability at work • Reduced central motor command is also documented in relation of encephalomyelitis • Subgroups of ME/CFS patients without muscle weakness are documented Abstract This commentary complements data reported in Clinical Biomechanics [1] reporting reduced maximal handgrip strength in numerous patients with myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) in proportion to their lowered maximal physical performances. The causes of muscle weakness in these patients are open to discussion. Literature data reveal a reduction of central command to skeletal muscles in some ME/CFS patients, related to encephalomyelitis. Altered muscle membrane excitability, that is “peripheral fatigue”, is also described in relation with an imbalance of the oxidant / anti-oxidant status. On the other hand, subgroups of chronically fatigued patients with clinical criteria of ME/CFS do not suffer from any muscle weakness.
    [Show full text]
  • Relationship Between Skin Temperature, Electrical
    International Journal of Environmental Research and Public Health Article Relationship between Skin Temperature, Electrical Manifestations of Muscle Fatigue, and Exercise-Induced Delayed Onset Muscle Soreness for Dynamic Contractions: A Preliminary Study Jose I. Priego-Quesada 1,2,* , Carlos De la Fuente 3,4,5 , Marcos R. Kunzler 3 , Pedro Perez-Soriano 1 , David Hervás-Marín 6 and Felipe P. Carpes 3 1 Research Group in Sport Biomechanics, Department of Physical Education and Sports, University of Valencia, 46010 Valencia, Spain; [email protected] 2 Biophysics and Medical Physics Group, Department of Physiology, University of Valencia, 46010 Valencia, Spain 3 Applied Neuromechanics Research Group, Laboratory of Neuromechanics, Federal University of Pampa, Uruguaiana RS 97500-970, Brazil; [email protected] (C.D.l.F.); [email protected] (M.R.K.); [email protected] (F.P.C.) 4 Carrera de Kinesiología, Departamento de Ciencias de la Salud, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 7820244, Chile 5 Centro de Salud Deportivo, Clínica Santa Maria, Santiago 7520380, Chile 6 Unidad de Bioestadística, Instituto de Investigación Sanitaria La Fe, 46026 Valencia, Spain; [email protected] * Correspondence: [email protected] Received: 15 August 2020; Accepted: 16 September 2020; Published: 18 September 2020 Abstract: Delayed onset muscle soreness (DOMS) indicates the presence of muscle damage and impairs force production and control. Monitorization of DOMS is useful to improving recovery intervention plans. The magnitude of DOMS may relate to muscle fatigue, which can be monitored by surface electromyography (EMG). Additionally, growing interest has been expressed in determining whether the skin temperature over a muscle group during exercise to fatigue could be a non-invasive marker for DOMS.
    [Show full text]
  • Pulmonary and Respiratory Muscle Function in Response to Marathon and Ultra‑Marathon Running: a Review
    Sports Medicine https://doi.org/10.1007/s40279-019-01105-w REVIEW ARTICLE Pulmonary and Respiratory Muscle Function in Response to Marathon and Ultra‑Marathon Running: A Review Nicholas B. Tiller1 © The Author(s) 2019 Abstract The physiological demands of marathon and ultra-marathon running are substantial, afecting multiple body systems. There have been several reviews on the physiological contraindications of participation; nevertheless, the respiratory implications have received relatively little attention. This paper provides an up-to-date review of the literature pertaining to acute pulmo- nary and respiratory muscle responses to marathon and ultra-marathon running. Pulmonary function was most commonly assessed using spirometry, with infrequent use of techniques including single-breath rebreathe and whole-body plethysmog- raphy. All studies observed statistically signifcant post-race reductions in one-or-more metrics of pulmonary function, with or without evidence of airway obstruction. Nevertheless, an independent analysis revealed that post-race values rarely fell below the lower-limit of normal and are unlikely, therefore, to be clinically signifcant. This highlights the virtue of healthy baseline parameters prior to competition and, although speculative, there may be more potent clinical manifestations in individuals with below-average baseline function, or those with pre-existing respiratory disorders (e.g., asthma). Respiratory muscle fatigue was most commonly assessed indirectly using maximal static mouth-pressure manoeuvres, and respiratory muscle endurance via maximum voluntary ventilation (MVV 12). Objective nerve-stimulation data from one study, and oth- ers documenting the time-course of recovery, implicate peripheral neuromuscular factors as the mechanism underpinning such fatigue. Evidence of respiratory muscle fatigue was more prevalent following marathon compared to ultra-marathon, and might be a factor of work rate, and thus exercise ventilation, which is tempered during longer races.
    [Show full text]