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Sample records for abdominal muscle fatigue

  1. The relationship between cough-specific quality of life and abdominal muscle endurance, fatigue, and depression in patients with COPD

    Arikan H

    2015-09-01

    Full Text Available Hulya Arikan,1 Sema Savci,2 Ebru Calik-Kutukcu,1 Naciye Vardar-Yagli,1 Melda Saglam,1 Deniz Inal-Ince,1 Lutfi Coplu31Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Hacettepe University, Ankara, Turkey; 2School of Physiotherapy and Rehabilitation, Dokuz Eylul University, Izmir, Turkey; 3Department of Chest Medicine, Faculty of Medicine, Hacettepe University, Ankara, TurkeyBackground: Cough is a prevalent symptom that impacts quality of life in COPD. The aim of this study was to assess the relationship between cough-specific quality of life, abdominal muscle endurance, fatigue, and depression in stable patients with COPD.Methods: Twenty-eight patients with COPD (mean age 60.6±8.7 years referred for pulmonary rehabilitation participated in this cross-sectional study. Sit-ups test was used for assessing abdominal muscle endurance. Leicester Cough Questionnare (LCQ was used to evaluate symptom-specific quality of life. Fatigue perception was evaluated with Fatigue Impact Scale (FIS. Beck Depression Inventory (BDI was used for assessing depression level.Results: The LCQ total score was significantly associated with number of sit-ups; BDI score; FIS total; physical, cognitive, and psychosocial scores (P<0.05. Scores of the LCQ physical, social, and psychological domains were also significantly related with number of sit-ups, FIS total score, and BDI score (P<0.05. FIS total score and number of sit-ups explained 58% of the variance in LCQ total score (r=0.76, r2=0.577, F(2–20=12.296, P<0.001.Conclusion: Chronic cough may adversely affect performance in daily life due to its negative effect on fatigue and decrease abdominal muscle endurance in patients with COPD. Decreased cough-related quality of life is related with increased level of depression in COPD patients. Effects of increased abdominal muscle endurance and decreased fatigue in COPD patients with chronic cough need further investigation.Keywords: cough, quality of

  2. Ischemia causes muscle fatigue

    Murthy, G.; Hargens, A. R.; Lehman, S.; Rempel, D. M.

    2001-01-01

    The purpose of this investigation was to determine whether ischemia, which reduces oxygenation in the extensor carpi radialis (ECR) muscle, causes a reduction in muscle force production. In eight subjects, muscle oxygenation (TO2) of the right ECR was measured noninvasively and continuously using near infrared spectroscopy (NIRS) while muscle twitch force was elicited by transcutaneous electrical stimulation (1 Hz, 0.1 ms). Baseline measurements of blood volume, muscle oxygenation and twitch force were recorded continuously, then a tourniquet on the upper arm was inflated to one of five different pressure levels: 20, 40, 60 mm Hg (randomized order) and diastolic (69 +/- 9.8 mm Hg) and systolic (106 +/- 12.8 mm Hg) blood pressures. Each pressure level was maintained for 3-5 min, and was followed by a recovery period sufficient to allow measurements to return to baseline. For each respective tourniquet pressure level, mean TO2 decreased from resting baseline (100% TO2) to 99 +/- 1.2% (SEM), 96 +/- 1.9%, 93 +/- 2.8%, 90 +/- 2.5%, and 86 +/- 2.7%, and mean twitch force decreased from resting baseline (100% force) to 99 +/- 0.7% (SEM), 96 +/- 2.7%, 93 +/- 3.1%, 88 +/- 3.2%, and 86 +/- 2.6%. Muscle oxygenation and twitch force at 60 mm Hg tourniquet compression and above were significantly lower (P forearm extensor muscle. Thus, ischemia associated with a modest decline in TO2 causes muscle fatigue.

  3. Ischemia causes muscle fatigue

    Murthy, G.; Hargens, A. R.; Lehman, S.; Rempel, D. M.

    2001-01-01

    The purpose of this investigation was to determine whether ischemia, which reduces oxygenation in the extensor carpi radialis (ECR) muscle, causes a reduction in muscle force production. In eight subjects, muscle oxygenation (TO2) of the right ECR was measured noninvasively and continuously using near infrared spectroscopy (NIRS) while muscle twitch force was elicited by transcutaneous electrical stimulation (1 Hz, 0.1 ms). Baseline measurements of blood volume, muscle oxygenation and twitch force were recorded continuously, then a tourniquet on the upper arm was inflated to one of five different pressure levels: 20, 40, 60 mm Hg (randomized order) and diastolic (69 +/- 9.8 mm Hg) and systolic (106 +/- 12.8 mm Hg) blood pressures. Each pressure level was maintained for 3-5 min, and was followed by a recovery period sufficient to allow measurements to return to baseline. For each respective tourniquet pressure level, mean TO2 decreased from resting baseline (100% TO2) to 99 +/- 1.2% (SEM), 96 +/- 1.9%, 93 +/- 2.8%, 90 +/- 2.5%, and 86 +/- 2.7%, and mean twitch force decreased from resting baseline (100% force) to 99 +/- 0.7% (SEM), 96 +/- 2.7%, 93 +/- 3.1%, 88 +/- 3.2%, and 86 +/- 2.6%. Muscle oxygenation and twitch force at 60 mm Hg tourniquet compression and above were significantly lower (P ischemia leading to a 7% or greater reduction in muscle oxygenation causes decreased muscle force production in the forearm extensor muscle. Thus, ischemia associated with a modest decline in TO2 causes muscle fatigue.

  4. Abdominal muscle training in sport.

    Norris, C M

    1993-01-01

    This paper evaluates several abdominal exercises, and highlights factors which are important for their safe prescription and effective use. The function of the abdominal muscles and hip flexors is considered, and the importance of the infra-umbilical portion of the rectus abdominis is emphasized. The effects of flexion on the lumbar spine are outlined. The trunk curl, sit-up, and straight leg raise are analysed, together with modifications of these exercises. The effect of foot fixation and h...

  5. DIMINISHED FATIGUE AT REDUCED MUSCLE LENGTH IN HUMAN SKELETAL MUSCLE

    Lee, Samuel C. K.; Braim, Anthony; Becker, Cara N.; Prosser, Laura A.; Tokay, Ann M.; Binder-Macleod, Stuart A.

    2007-01-01

    Understanding muscle fatigue properties at different muscle lengths is essential to improve electrical stimulation applications in which impaired muscle is activated to produce function or to serve as an orthotic assist. This study examined the effects of muscle length on fatigue in human quadriceps muscle. Twelve healthy subjects were tested at short and long muscle lengths (15° and 90° of knee flexion, respectively) before and after a fatigue-producing protocol using low-, high-, and variab...

  6. Exercise-induced respiratory muscle fatigue: implications for performance

    Romer, LM; Polkey, MI

    2008-01-01

    It is commonly held that the respiratory system has ample capacity relative to the demand for maximal O-2 and CO2 transport in healthy humans exercising near sea level. However, this situation may not apply during heavy-intensity, sustained exercise where exercise may encroach on the capacity of the respiratory system. Nerve stimulation techniques have provided objective evidence that the diaphragm and abdominal muscles are susceptible to fatigue with heavy, sustained exercise. The fatigue ap...

  7. Muscle glycogen stores and fatigue

    Ørtenblad, Niels; Westerblad, Håkan; Nielsen, Joachim

    2013-01-01

      Studies performed at the beginning of the last century revealed the importance of carbohydrate as a fuel during exercise, and the importance of muscle glycogen on performance has subsequently been confirmed in numerous studies. However, the link between glycogen depletion and impaired muscle...... function during fatigue is not well understood and a direct cause-and-effect relationship between glycogen and muscle function remains to be established. The use of electron microscopy has revealed that glycogen is not homogeneously distributed in skeletal muscle fibres, but rather localized in distinct...... pools. Furthermore, each glycogen granule has its own metabolic machinery with glycolytic enzymes and regulating proteins. One pool of such glycogenolytic complexes is localized within the myofibrils in close contact with key proteins involved in the excitation-contraction coupling and Ca2+ release from...

  8. Biomarkers of peripheral muscle fatigue during exercise

    Finsterer Josef

    2012-01-01

    Abstract Background Biomarkers of peripheral muscle fatigue (BPMFs) are used to offer insights into mechanisms of exhaustion during exercise in order to detect abnormal fatigue or to detect defective metabolic pathways. This review aims at describing recent advances and future perspectives concerning the most important biomarkers of muscle fatigue during exercise. Results BPMFs are classified according to the mechanism of fatigue related to adenosine-triphosphate-metabolism, acidosis, or oxid...

  9. Human Muscle Fatigue Model in Dynamic Motions

    Ma, Ruina; Chablat, Damien; Bennis, Fouad; Ma, Liang

    2012-01-01

    Human muscle fatigue is considered to be one of the main reasons for Musculoskeletal Disorder (MSD). Recent models have been introduced to define muscle fatigue for static postures. However, the main drawbacks of these models are that the dynamic effect of the human and the external load are not taken into account. In this paper, each human joint is assumed to be controlled by two muscle groups to generate motions such as push/pull. The joint torques are computed using Lagrange's formulation ...

  10. Abdominal muscle function and incisional hernia

    Jensen, K K; Kjaer, M; Jorgensen, L N

    2014-01-01

    PURPOSE: Although ventral incisional hernia (VIH) repair in patients is often evaluated in terms of hernia recurrence rate and health-related quality of life, there is no clear consensus regarding optimal operative treatment based on these parameters. It was proposed that health-related quality...... of life depends largely on abdominal muscle function (AMF), and the present review thus evaluates to what extent AMF is influenced by VIH and surgical repair. METHODS: The PubMed and EMBASE databases were searched for articles following a systematic strategy for inclusion. RESULTS: A total of seven...... studies described AMF in relation to VIH. Five studies examined AMF using objective isokinetic dynamometers to determine muscle strength, and two studies examined AMF by clinical examination-based muscle tests. CONCLUSION: Both equipment-related and functional muscle tests exist for use in patients...

  11. Human Muscle Fatigue Model in Dynamic Motions

    Ma, Ruina; Bennis, Fouad; Ma, Liang

    2012-01-01

    Human muscle fatigue is considered to be one of the main reasons for Musculoskeletal Disorder (MSD). Recent models have been introduced to define muscle fatigue for static postures. However, the main drawbacks of these models are that the dynamic effect of the human and the external load are not taken into account. In this paper, each human joint is assumed to be controlled by two muscle groups to generate motions such as push/pull. The joint torques are computed using Lagrange's formulation to evaluate the dynamic factors of the muscle fatigue model. An experiment is defined to validate this assumption and the result for one person confirms its feasibility. The evaluation of this model can predict the fatigue and MSD risk in industry production quickly.

  12. MR spectroscopy studies of human muscle fatigue

    To investigate the relationship between fatigue and metabolism, P-31 MR spectra of human muscle were obtained while simultaneously monitoring force production, before, during, and following aerobic and anaerobic exercise. Changes of PCr and Pi showed a nonlinear relationship to fatigue

  13. Abdominal muscle paralysis associated with herpes zoster.

    Gottschau, P; Trojaborg, W

    1991-10-01

    We describe a 77-year-old women with cutaneous herpes zoster in the area of the right T9-T11 dermatomes complicated by abdominal muscle paralysis. Four months after onset of paralysis, stimulation of appropriate intercostal nerves failed to evoke responses from the corresponding segments of the rectus abdominis muscle. Three months later EMG of these muscle segments revealed profuse denervation activity and spontaneous long-lasting burst of high frequency discharges. Magnetic stimulation applied transcranially and peripherally at T10 evoked responses from the left, but not from the right paralytic rectus abdominis muscle. Electric stimulation of right T10 elicited a markedly delayed, prolonged and polyphasic response in the transverse abdominis muscle and EMG revealed polyphasia and increased motor unit potential duration in muscle segments underlying herpes zoster eruption. One and a half years after onset, the paralysis of the rectus abdominis muscle was still present. A survey of the literature concerning this rare type of zoster paralysis is presented. PMID:1837649

  14. Mechanisms of exertional fatigue in muscle glycogenoses

    Vissing, John; Haller, Ronald G

    2012-01-01

    relates directly to the metabolic defect, but also to substrate-limited energy deficiency, as exemplified by the "second wind" phenomenon in McArdle disease. A number of secondary events may also play a role in inducing premature fatigue in glycogenoses, including (1) absent or blunted muscle acidosis...... concentrations of extracellular potassium in exercising muscle and (3) exaggerated accumulation of ADP during exercise that may inhibit sodium-potassium and calcium-ATPases. Disorders of muscle glycogenolysis and glycolysis reveal the crucial role of these metabolic processes for supplying both anaerobic and...... aerobic energy for muscle contraction; and the pathological fatigue that occurs when glycogenolysis and/or glycolysis is blocked imply an important role for theses metabolic pathways in normal muscle fatigue....

  15. Understanding Muscle Dysfunction in Chronic Fatigue Syndrome

    Gina Rutherford

    2016-01-01

    Full Text Available Introduction. Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME is a debilitating disorder of unknown aetiology, characterised by severe disabling fatigue in the absence of alternative diagnosis. Historically, there has been a tendency to draw psychological explanations for the origin of fatigue; however, this model is at odds with findings that fatigue and accompanying symptoms may be explained by central and peripheral pathophysiological mechanisms, including effects of the immune, oxidative, mitochondrial, and neuronal pathways. For example, patient descriptions of their fatigue regularly cite difficulty in maintaining muscle activity due to perceived lack of energy. This narrative review examined the literature for evidence of biochemical dysfunction in CFS/ME at the skeletal muscle level. Methods. Literature was examined following searches of PUB MED, MEDLINE, and Google Scholar, using key words such as CFS/ME, immune, autoimmune, mitochondria, muscle, and acidosis. Results. Studies show evidence for skeletal muscle biochemical abnormality in CFS/ME patients, particularly in relation to bioenergetic dysfunction. Discussion. Bioenergetic muscle dysfunction is evident in CFS/ME, with a tendency towards an overutilisation of the lactate dehydrogenase pathway following low-level exercise, in addition to slowed acid clearance after exercise. Potentially, these abnormalities may lead to the perception of severe fatigue in CFS/ME.

  16. Understanding Muscle Dysfunction in Chronic Fatigue Syndrome.

    Rutherford, Gina; Manning, Philip; Newton, Julia L

    2016-01-01

    Introduction. Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a debilitating disorder of unknown aetiology, characterised by severe disabling fatigue in the absence of alternative diagnosis. Historically, there has been a tendency to draw psychological explanations for the origin of fatigue; however, this model is at odds with findings that fatigue and accompanying symptoms may be explained by central and peripheral pathophysiological mechanisms, including effects of the immune, oxidative, mitochondrial, and neuronal pathways. For example, patient descriptions of their fatigue regularly cite difficulty in maintaining muscle activity due to perceived lack of energy. This narrative review examined the literature for evidence of biochemical dysfunction in CFS/ME at the skeletal muscle level. Methods. Literature was examined following searches of PUB MED, MEDLINE, and Google Scholar, using key words such as CFS/ME, immune, autoimmune, mitochondria, muscle, and acidosis. Results. Studies show evidence for skeletal muscle biochemical abnormality in CFS/ME patients, particularly in relation to bioenergetic dysfunction. Discussion. Bioenergetic muscle dysfunction is evident in CFS/ME, with a tendency towards an overutilisation of the lactate dehydrogenase pathway following low-level exercise, in addition to slowed acid clearance after exercise. Potentially, these abnormalities may lead to the perception of severe fatigue in CFS/ME. PMID:26998359

  17. Biomarkers of peripheral muscle fatigue during exercise

    Finsterer Josef

    2012-11-01

    Full Text Available Abstract Background Biomarkers of peripheral muscle fatigue (BPMFs are used to offer insights into mechanisms of exhaustion during exercise in order to detect abnormal fatigue or to detect defective metabolic pathways. This review aims at describing recent advances and future perspectives concerning the most important biomarkers of muscle fatigue during exercise. Results BPMFs are classified according to the mechanism of fatigue related to adenosine-triphosphate-metabolism, acidosis, or oxidative-metabolism. Muscle fatigue is also related to an immunological response. impaired calcium handling, disturbances in bioenergetic pathways, and genetic responses. The immunological and genetic response may make the muscle susceptible to fatigue but may not directly cause muscle fatigue. Production of BPMFs is predominantly dependent on the type of exercise. BPMFs need to change as a function of the process being monitored, be stable without appreciable diurnal variations, correlate well with exercise intensity, and be present in detectable amounts in easily accessible biological fluids. The most well-known BPMFs are serum lactate and interleukin-6. The most widely applied clinical application is screening for defective oxidative metabolism in mitochondrial disorders by means of the lactate stress test. The clinical relevance of most other BPMFs, however, is under debate, since they often depend on age, gender, physical fitness, the energy supply during exercise, the type of exercise needed to produce the BPMF, and whether healthy or diseased subjects are investigated. Conclusions Though the role of BPMFs during fatigue is poorly understood, measuring BPMFs under specific, standardised conditions appears to be helpful for assessing biological states or processes during exercise and fatigue.

  18. Reduced Muscle Glycogen Differentially Affects Exercise Performance and Muscle Fatigue

    Simon Lees; Williams, Jay H; Batts, Timothy W.

    2013-01-01

    This investigation examined the effects of reduced muscle glycogen on exercise performance and muscle fatigue. Male rats were assigned to a low glycogen group (LG) that participated in a protocol of exercise and fasting, a high glycogen group (HG) that exercised but were allowed free access to food, or control group (CON) that did not exercise but were allowed free access to food. Following the protocol, muscle glycogen content of the LG animals was reduced by 45%. The LG animals also perform...

  19. Effects of Local and Widespread Muscle Fatigue on Movement Timing

    Cowley, Jeffrey C.; Dingwell, Jonathan B.; Gates, Deanna H.

    2014-01-01

    Repetitive movements can cause muscle fatigue, leading to motor reorganization, performance deficits, and/or possible injury. The effects of fatigue may depend on the type of fatigue task employed, however. The purpose of this study was to determine how local fatigue of a specific muscle group versus widespread fatigue of various muscle groups affected the control of movement timing. Twenty healthy subjects performed an upper-extremity low-load work task similar to sawing for 5 continuous min...

  20. Experimental Validation of a New Dynamic Muscle Fatigue Model

    Seth, Deep; Chablat, Damien; Sakka, Sophie; Bennis, Fouad

    2016-01-01

    Muscle fatigue is considered as one of the major risk factor causing Musculo-Skeletal Disorder (MSD). To avoid MSD the study of muscle fatigue is very important. For the study of muscle fatigue a new model is developed by modifying the Ruina Ma's dynamic muscle fatigue model and introducing the muscle co-contraction factor 'n' in this model.The aim of this paper is to experimentally validate a dynamic muscle fatigue model using Electromyography (EMG) and Maximum Voluntary Contraction (MVC) da...

  1. Determination of subject-specific muscle fatigue rates under static fatiguing operations

    Ma, Liang; Zhang, Wei; Hu, Bo; Chablat, Damien; Bennis, Fouad; Guillaume, François

    2013-01-01

    Cumulative local muscle fatigue may lead to potential musculoskeletal disorder (MSD) risks {\\color{red}, and subject-specific muscle fatigability needs to be considered to reduce potential MSD risks.} This study was conducted to determine local muscle fatigue rate at shoulder joint level based on an exponential function derived from a muscle fatigue model. Forty male subjects participated in a fatiguing operation under a static posture with a range of relative force levels (14\\% - 33\\%). Rema...

  2. Muscle Fatigue Increases the Probability of Developing Hyperalgesia in Mice

    Yokoyama, Takeshi; Lisi, Tammy L.; Moore, Steven A.; Sluka, Kathleen A.

    2007-01-01

    Chronic muscle pain is a major clinical problem that is often associated with fatigue. Conversely, chronic fatigue conditions are commonly associated with muscle pain. We tested the hypothesis that muscle fatigue enhances hyperalgesia associated with injection of acidic saline into muscle. We evaluated mechanical sensitivity of the paw (von Frey) in mice after 2 intramuscular injections of saline (20 µL; pH 4, pH 5, pH 6, pH 7.2) in a fatigue and a control group. To induce fatigue, mice were ...

  3. The effect of muscle fatigue on the behavior of single muscle fibre

    Číhalová L.

    2007-01-01

    The aim of this study is to integrate the effect of muscle fatigue into skeletal muscle fibre model. The base of the skeletal muscle model previously developed in our laboratory is the sliding cross bridge theory of contraction. The calcium activation, which is the base stone for the contraction, is integrated. The muscle fatigue is often described as a decline in the muscle ability to generate force. It is the result of the sustained contraction of long duration. Generally, muscle fatigue is...

  4. Experimental studies of spinal mechanisms associated with muscle fatigue

    Kalezic, Ivana

    2004-01-01

    Muscle fatigue is ubiquitous in every day life.Muscle fatigue might be considered as an altered state of motor behaviour, which impairs motor performance. By contrast, muscle fatigue could also be considered a positive phenomenon, which protects muscle tissue from damage that might be incurred to it by overuse. The principal aim of the thesis was to explore some of the mechanisms of muscle fatigue at the spinal level in animal models.The activation of multiple motor units of a single calf mus...

  5. Effects of Local and Widespread Muscle Fatigue on Movement Timing

    Cowley, Jeffrey C.; Dingwell, Jonathan B.; Gates, Deanna H.

    2014-01-01

    Repetitive movements can cause muscle fatigue, leading to motor reorganization, performance deficits, and/or possible injury. The effects of fatigue may depend on the type of fatigue task employed, however. The purpose of this study was to determine how local fatigue of a specific muscle group versus widespread fatigue of various muscle groups affected the control of movement timing. Twenty healthy subjects performed an upper-extremity low-load work task similar to sawing for 5 continuous minutes both before and after completing a protocol that either fatigued all the muscles used in the task (widespread fatigue) or a protocol that selectively fatigued the primary muscles used to execute the pushing stroke of the sawing task (localized fatigue). Subjects were instructed to time their movements with a metronome. Timing error, movement distance, and speed were calculated for each movement. Data were then analyzed using a goal-equivalent manifold (GEM) approach to quantify changes in goal-relevant and non-goal-relevant variability. We applied detrended fluctuation analysis to each time series to quantify changes in fluctuation dynamics that reflected changes in the control strategies used. After localized fatigue, subjects made shorter, slower movements and exerted greater control over non-goal-relevant variability. After widespread fatigue, subjects exerted less control over non-goal-relevant variability and did not change movement patterns. Thus, localized and widespread muscle fatigue affected movement differently. Local fatigue may reduce the available motor solutions and therefore cause greater movement reorganization than widespread muscle fatigue. Subjects altered their control strategies but continued to achieve the timing goal after both fatigue tasks. PMID:25183157

  6. Muscle fatigue in fibromyalgia is in the brain, not in the muscles

    Bandak, Elisabeth; Amris, Kirstine; Bliddal, Henning;

    2013-01-01

    To investigate relationships between perceived and objectively measured muscle fatigue during exhausting muscle contractions in women with fibromyalgia (FM) compared with healthy controls (HC).......To investigate relationships between perceived and objectively measured muscle fatigue during exhausting muscle contractions in women with fibromyalgia (FM) compared with healthy controls (HC)....

  7. Degree of muscle fatigue in children with chronic juvenile arthritis

    Sekulić Aleksandra; Stevanović Srbislav; Milićević Saša; Gicić-Skenderi Suada

    2011-01-01

    The aim of our work was to identify gradient of the muscle fatigue of some muscle groups, among children with chronic juvenile arthritis, which are restricted in function by existing limitation in range of motions. Four patients in age of 9,5, with mentioned diagnosis were examined. Healthy subjects, with same ages were control group. Manuel muscle test, range of motion test and EMG examination were performed. Results shown significance difference in degree of muscle fatigue among observed pa...

  8. Muscle fatigue degrades force sense at the ankle joint.

    Vuillerme, Nicolas; Boisgontier, Matthieu

    2008-01-01

    To investigate the effects of muscle fatigue on force sense at the ankle joint, 10 young healthy adults were asked to perform an isometric contra-lateral force ankle-matching task in two experimental conditions of: (1) no-fatigue and (2) fatigue of the plantar-flexor muscles. Measures of the overall accuracy and the variability of the force matching performances were determined using the absolute error and the variable error, respectively. Results showed less accurate and less consistent forc...

  9. Degree of muscle fatigue in children with chronic juvenile arthritis

    Sekulić Aleksandra

    2011-01-01

    Full Text Available The aim of our work was to identify gradient of the muscle fatigue of some muscle groups, among children with chronic juvenile arthritis, which are restricted in function by existing limitation in range of motions. Four patients in age of 9,5, with mentioned diagnosis were examined. Healthy subjects, with same ages were control group. Manuel muscle test, range of motion test and EMG examination were performed. Results shown significance difference in degree of muscle fatigue among observed patients, which explain decrease of muscle efficiency and must be taken when intensity of kinesitherapic treatment has to be done. It is concluded that structural changes on locomotory system induce secondary hypertrophy or atrophy of the muscle system and increase of muscle fatigue when activity of certain muscles is performed.

  10. Correlation between Peak Expiratory Flow and Abdominal Muscle Thickness

    Ishida, Hiroshi; Kobara, Kenichi; Osaka, Hiroshi; Suehiro, Tadanobu; Ito, Tomotaka; Kurozumi, Chiharu; Watanabe, Susumu

    2014-01-01

    [Purpose] The purpose of this study was to determine whether forced expiration is correlated with abdominal muscle thickness. [Subjects] Twenty-three healthy male volunteers participated in this study. [Methods] The peak expiratory flow (PEF) was obtained using a peak flow meter with subjects in the sitting position. The thicknesses of the right rectus abdominis, external oblique, internal oblique, and transverse abdominis muscles were measured using B-mode ultrasonography at the end of a rel...

  11. Severity of Giardia infection associated with post-infectious fatigue and abdominal symptoms two years after

    Rortveit Guri; Hanevik Kurt; Mørch Kristine; Wensaas Knut-Arne; Eide Geir; Hausken Trygve; Langeland Nina

    2009-01-01

    Abstract Background A high rate of post-infectious fatigue and abdominal symptoms two years after a waterborne outbreak of giardiasis in Bergen, Norway in 2004 has previously been reported. The aim of this report was to identify risk factors associated with such manifestations. Methods All laboratory confirmed cases of giardiasis (n = 1262) during the outbreak in Bergen in 2004 received a postal questionnaire two years after. Degree of post-infectious abdominal symptoms and fatigue, as well a...

  12. MUSCLE METABOLISM WITH BLOOD FLOW RESTRICTION IN CHRONIC FATIGUE SYNDROME

    McCully, Kevin K; Smith, Sinclair; Rajaei, Sheeva; Leigh, John S.; Natelson, Benjamin H

    2003-01-01

    The purpose of this study was to determine if chronic fatigue syndrome (CFS) is associated with reduced blood flow and muscle oxidative metabolism. Patients with CFS according to CDC criteria (n=19) were compared to normal sedentary subjects (n = 11). Muscle blood flow was measured in the femoral artery with Doppler ultrasound after exercise. Muscle metabolism was measured in the medial gastrocnemius muscle using 31P magnetic resonance spectroscopy (MRS). Muscle oxygen saturation and blood vo...

  13. Skeletal Muscle Fatigue in Old Age: Whose Advantage?

    Kent-Braun, Jane A.

    2009-01-01

    The results of recent studies indicate that, in healthy men and women beyond ~65 years of age, the energy-producing pathways in skeletal muscle may combine with changes in motor unit behavior and muscle contractile properties to provide a unique environment for resisting muscle fatigue.

  14. SHIFTING OF ACTIVATION CENTER IN THE BRAIN DURING MUSCLE FATIGUE: AN EXPLANATION OF MINIMAL CENTRAL FATIGUE?

    Liu, Jing Z; Lewandowski, Beth; Karakasis, Chris; Yao, Bing; Siemionow, Vlodek; Sahgal, Vinod; Yue, Guang H

    2007-01-01

    Accumulating evidence suggests that the overall level of cortical activation controlling a voluntary motor task that leads to significant muscle fatigue does not decrease as much as the activation level of the motoneuron pool projecting to the muscle. One possible explanation for this “muscle fatigue>cortical fatigue” phenomenon is that the brain is an organ with built-in redundancies: it has multiple motor centers and parallel pathways, and the center of activation may shift from one locatio...

  15. Indoor mobility-related fatigue and muscle strength in nonagenarians

    Mänty, Minna; Ekmann, Anette; Thinggaard, Mikael;

    2014-01-01

    strength decline in nonagenarians. METHODS: The study is based on a prospective longitudinal study of all Danes born in 1905 and assessed in 1998, 2000 and 2003, and includes 92- to 93-year-old persons who were independent of help in basic indoor mobility at baseline (n = 1,353). Fatigue was assessed at...... baseline and defined as a subjective feeling of fatigue when transferring or walking indoors. The outcome measure, maximum grip strength, was measured at each measurement point. RESULTS: Grip strength declined throughout the study in participants with and without fatigue, but those reporting fatigue had...... significantly (P < .001) lower muscle strength during the entire study period. Longitudinal analyses indicated slightly slower decline in muscle strength among participants with fatigue compared to those without; however, observed selective dropout of participants with fatigue and poor performance at baseline...

  16. Increased fatigue resistance of respiratory muscles during exercise after respiratory muscle endurance training

    Verges, S; Lenherr, O; Haner, A C; Schulz, C.; Spengler, C M

    2007-01-01

    Respiratory muscle fatigue develops during exhaustive exercise and can limit exercise performance. Respiratory muscle training, in turn, can increase exercise performance. We investigated whether respiratory muscle endurance training (RMT) reduces exercise-induced inspiratory and expiratory muscle fatigue. Twenty-one healthy, male volunteers performed twenty 30-min sessions of either normocapnic hyperpnoea (n = 13) or sham training (CON, n = 8) over 4-5 wk. Before and after training, subjects...

  17. The effect of massage on localized lumbar muscle fatigue

    Leisman Gerry; Tanaka Tim; Mori Hidetoshi; Nishijo Kazushi

    2002-01-01

    Abstract Background There is not enough evidence to support the efficacy of massage for muscle fatigue despite wide utilization of the modality in various clinical settings. This study investigated the influence of massage application on localized back muscle fatigue. Methods Twenty-nine healthy subjects participated in two experimental sessions (massage and rest conditions). On each test day, subjects were asked to lie in the prone position on a treatment table and perform sustained back ext...

  18. Understanding Muscle Dysfunction in Chronic Fatigue Syndrome

    Gina Rutherford; Philip Manning; Newton, Julia L

    2016-01-01

    Introduction. Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a debilitating disorder of unknown aetiology, characterised by severe disabling fatigue in the absence of alternative diagnosis. Historically, there has been a tendency to draw psychological explanations for the origin of fatigue; however, this model is at odds with findings that fatigue and accompanying symptoms may be explained by central and peripheral pathophysiological mechanisms, including effects of the immune...

  19. Effect of acute hypoxia on respiratory muscle fatigue in healthy humans

    Verges Samuel

    2010-08-01

    Full Text Available Abstract Background Greater diaphragm fatigue has been reported after hypoxic versus normoxic exercise, but whether this is due to increased ventilation and therefore work of breathing or reduced blood oxygenation per se remains unclear. Hence, we assessed the effect of different blood oxygenation level on isolated hyperpnoea-induced inspiratory and expiratory muscle fatigue. Methods Twelve healthy males performed three 15-min isocapnic hyperpnoea tests (85% of maximum voluntary ventilation with controlled breathing pattern in normoxic, hypoxic (SpO2 = 80% and hyperoxic (FiO2 = 0.60 conditions, in a random order. Before, immediately after and 30 min after hyperpnoea, transdiaphragmatic pressure (Pdi,tw was measured during cervical magnetic stimulation to assess diaphragm contractility, and gastric pressure (Pga,tw was measured during thoracic magnetic stimulation to assess abdominal muscle contractility. Two-way analysis of variance (time x condition was used to compare hyperpnoea-induced respiratory muscle fatigue between conditions. Results Hypoxia enhanced hyperpnoea-induced Pdi,tw and Pga,tw reductions both immediately after hyperpnoea (Pdi,tw : normoxia -22 ± 7% vs hypoxia -34 ± 8% vs hyperoxia -21 ± 8%; Pga,tw : normoxia -17 ± 7% vs hypoxia -26 ± 10% vs hyperoxia -16 ± 11%; all P di,tw : normoxia -10 ± 7% vs hypoxia -16 ± 8% vs hyperoxia -8 ± 7%; Pga,tw : normoxia -13 ± 6% vs hypoxia -21 ± 9% vs hyperoxia -12 ± 12%; all P di,tw or Pga,tw reductions was observed between normoxic and hyperoxic conditions. Also, heart rate and blood lactate concentration during hyperpnoea were higher in hypoxia compared to normoxia and hyperoxia. Conclusions These results demonstrate that hypoxia exacerbates both diaphragm and abdominal muscle fatigability. These results emphasize the potential role of respiratory muscle fatigue in exercise performance limitation under conditions coupling increased work of breathing and reduced O2 transport as

  20. Abdominal perforator vs. muscle sparing flaps for breast reconstruction.

    Butler, Paris D; Wu, Liza C

    2015-06-01

    Abdominally based free flaps have become the mainstay for women that desire to use their own tissue as a means of breast reconstruction after mastectomy. As the techniques have evolved, significant effort has been invested in finding the best means of minimizing morbidity to the abdominal donor site while ensuring a viable reconstructed breast that is aesthetically pleasing. This manuscript reviews and compares the muscle sparing free transverse rectus abdominis myocutaneous (MsfTRAM), the deep inferior epigastric artery perforator (DIEP), and the superficial inferior epigastric artery (SIEA) flaps, regarding flap success rate, operative times, abdominal donor site morbidity and residual functionality, hospital lengths of stay and associated costs, impact of co-morbid conditions, and resilience after adjuvant radiation treatment. PMID:26161306

  1. The Pilates Method increases respiratory muscle strength and performance as well as abdominal muscle thickness.

    Giacomini, Mateus Beltrame; da Silva, Antônio Marcos Vargas; Weber, Laura Menezes; Monteiro, Mariane Borba

    2016-04-01

    The aim of this study was to verify the effects of the Pilates Method (PM) training program on the thickness of the abdominal wall muscles, respiratory muscle strength and performance, and lung function. This uncontrolled clinical trial involved 16 sedentary women who were assessed before and after eight weeks of PM training. The thickness of the transversus abdominis (TrA), internal oblique (IO) and external oblique (EO) muscles was assessed. The respiratory muscle strength was assessed by measuring the maximum inspiratory (MIP) and expiratory (MEP) pressure. The lung function and respiratory muscle performance were assessed by spirometry. An increase was found in MIP (p = 0.001), MEP (p = 0.031), maximum voluntary ventilation (p = 0.020) and the TrA (p < 0.001), IO (p = 0.002) and EO (p < 0.001) thickness after the PM program. No alterations in lung function were found. These findings suggest that the PM program promotes abdominal wall muscle hypertrophy and an increase in respiratory muscle strength and performance, preventing weakness in abdominal muscles and dysfunction in ventilatory mechanics, which could favor the appearance of illnesses. PMID:27210841

  2. Severity of Giardia infection associated with post-infectious fatigue and abdominal symptoms two years after

    Rortveit Guri

    2009-12-01

    Full Text Available Abstract Background A high rate of post-infectious fatigue and abdominal symptoms two years after a waterborne outbreak of giardiasis in Bergen, Norway in 2004 has previously been reported. The aim of this report was to identify risk factors associated with such manifestations. Methods All laboratory confirmed cases of giardiasis (n = 1262 during the outbreak in Bergen in 2004 received a postal questionnaire two years after. Degree of post-infectious abdominal symptoms and fatigue, as well as previous abdominal problems, was recorded. In the statistical analyses number of treatment courses, treatment refractory infection, delayed education and sick leave were used as indices of protracted and severe Giardia infection. Age, gender, previous abdominal problems and symptoms during infection were also analysed as possible risk factors. Simple and multiple ordinal logistic regression models were used for the analyses. Results The response rate was 81% (1017/1262, 64% were women and median age was 31 years (range 3-93, compared to 61% women and 30 years (range 2-93 among all 1262 cases. Factors in multiple regression analysis significantly associated with abdominal symptoms two years after infection were: More than one treatment course, treatment refractory infection, delayed education, bloating and female gender. Abdominal problems prior to Giardia infection were not associated with post-infectious abdominal symptoms. More than one treatment course, delayed education, sick leave more than 2 weeks, and malaise at the time of infection, were significantly associated with fatigue in the multiple regression analysis, as were increasing age and previous abdominal problems. Conclusion Protracted and severe giardiasis seemed to be a risk factor for post-infectious fatigue and abdominal symptoms two years after clearing the Giardia infection.

  3. Clinical Observation on the Effects of Bo's Abdominal Acupuncture in 40 Cases of Chronic Fatigue Syndrome

    HUANG Yong; LIAO Xiao-ming; LI xiao-xi; SONG Yuan-bin

    2008-01-01

    objective;To observe the curative effect of Bo's abdominal acupuncture on chronic fatigue syndrome(CFS).Methods;Forty cases with CFS were treated by Bo's abdominal acupuncture at me points for conducting qi back to its origin and 4 points on the abdomen once a dav for 2 weeks.Scores for symptoms and scores for fatigue questionnaires were compared before and after treatment.Results;After treatment,the clinical symptoms of patients were differently alleviated,and scores for symptoms,mental condition and neural feeling in questionnaires on fatigue were obviously reduced(P<0.01-0.05).Conclusion;Bo's abdominal acupuncture has a good curative effect on general disease with complex symptoms,especially on lassitude,anorlexia,insomnia,amnesia,diarrhea,and general pain.

  4. Framework for Dynamic Evaluation of Muscle Fatigue in Manual Handling Work

    Ma, Liang; Chablat, Damien; Zhang, Wei

    2008-01-01

    Muscle fatigue is defined as the point at which the muscle is no longer able to sustain the required force or work output level. The overexertion of muscle force and muscle fatigue can induce acute pain and chronic pain in human body. When muscle fatigue is accumulated, the functional disability can be resulted as musculoskeletal disorders (MSD). There are several posture exposure analysis methods useful for rating the MSD risks, but they are mainly based on static postures. Even in some fatigue evaluation methods, muscle fatigue evaluation is only available for static postures, but not suitable for dynamic working process. Meanwhile, some existing muscle fatigue models based on physiological models cannot be easily used in industrial ergonomic evaluations. The external dynamic load is definitely the most important factor resulting muscle fatigue, thus we propose a new fatigue model under a framework for evaluating fatigue in dynamic working processes. Under this framework, virtual reality system is taken to ...

  5. Effect of muscle acidity on muscle metabolism and fatigue during intense exercise in man

    Bangsbo, Jens; Madsen, K.; Kiens, Bente;

    1996-01-01

    (kg wet weight)-1 min-1). The rate of muscle glycogen breakdown was the same in C and HL (8.1 +/- 1.2 vs. 8.2 +/- 1.0 mmol (kg wet weight)-1 min-1). 5. The present data suggest that elevated muscle acidity does not reduce muscle glycogenolysis/glycolysis and is not the only cause of fatigue during...

  6. Coexistence of potentiation and fatigue in skeletal muscle

    D.E. Rassier; B.R. MacIntosh

    2000-01-01

    Twitch potentiation and fatigue in skeletal muscle are two conditions in which force production is affected by the stimulation history. Twitch potentiation is the increase in the twitch active force observed after a tetanic contraction or during and following low-frequency stimulation. There is evidence that the mechanism responsible for potentiation is phosphorylation of the regulatory light chains of myosin, a Ca2+-dependent process. Fatigue is the force decrease observed after a period of ...

  7. CORRELATIONS BETWEEN MUSCLE MASS, MUSCLE STRENGTH, PHYSICAL PERFORMANCE, AND MUSCLE FATIGUE RESISTANCE IN COMMUNITY-DWELLING ELDERLY SUBJECTS

    Elizabeth

    2016-03-01

    Full Text Available Objective: To determine the correlations between muscle mass, muscle strength, physical performance, and muscle fatigue resistance in community-dwelling elderly people in order to elucidate factors which contribute to elderly’s performance of daily activities. Methods: A cross-sectional study was conducted on community-dwelling elderly in Bandung from September to December 2014. One hundred and thirty elderly, 60 years old or above, were evaluated using bioelectrical impedance analysis to measure muscle mass; grip strength to measure muscle strength and muscle fatigue resistance; habitual gait speed to measure physical performance; and Global Physical Activity Questionnaire (GPAQ to assess physical activity. Results: There were significant positive correlations between muscle mass (r=0,27, p=0,0019, muscle strength (r=0,26, p=0,0024, and physical performance (r=0,32, p=0,0002 with muscle fatigue resistance. Physical performance has the highest correlation based on multiple regression test (p=0,0025. In association with muscle mass, the physical activity showed a significant positive correlation (r=0,42, p=0,0000. Sarcopenia was identified in 19 (14.61% of 130 subjects. Conclusions: It is suggested that muscle mass, muscle strength, and physical performance influence muscle fatigue resistance.

  8. Muscle fatigue does not lead to increased instability of upper extremity repetitive movements

    Gates, Deanna H.; Dingwell, Jonathan B.

    2009-01-01

    Muscle fatigue alters neuromuscular responses. This may lead to increased sensitivity to perturbations and possibly to subsequent injury risk. We studied the effects of muscle fatigue on movement stability during a repetitive upper extremity task. Twenty healthy young subjects performed a repetitive work task, similar to sawing, synchronized with a metronome before and after performing each of two fatiguing tasks. The first fatigue task (“LIFT”) primarily fatigued the shoulder flexor muscles,...

  9. How different modes of child delivery influence abdominal muscle activities in the active straight leg raise.

    Kwon, Yu-Jeong; Hyung, Eun-Ju; Yang, Kyung-Hye; Lee, Hyun-Ok

    2014-08-01

    [Purpose] The purpose of this study was to examine the activities of the abdominal muscles of women who had experienced vaginal delivery in comparison with those who had experienced Cesarean childbirth. [Subjects and Methods] A total of 14 subjects (7 vaginal delivery, 7 Cesarean section) performed an active straight leg raise to 20 cm above the ground, and we measured the activities of the internal oblique abdominal muscle, the external oblique abdominal muscle, and the rectus abdominal muscle on both sides using electromyography. The effort required to raise the leg was scored on a Likert scale. Then, the subjects conducted maximum isometric contraction for hip joint flexion with the leg raised at 20 cm, and maximum torque and abdominal muscle activities were measured using electromyography. [Results] During the active straight leg raise, abdominal muscle activities were higher in the Cesarean section subjects. The Likert scale did not show a significant difference. The activities of the abdominal muscles and the maximum torque of the hip joint flexion at maximum isometric contraction were higher in the vaginal delivery subjects. [Conclusion] The abdominal muscles of Cesarean section subjects showed greater recruitment for maintaining pelvic stability during the active straight leg raising, but were relatively weaker when powerful force was required. Therefore, we consider that more abdominal muscle training is necessary for maintaining pelvic stability of Cesarean section subjects. PMID:25202194

  10. Muscle damage and its relationship with muscle fatigue during a half-iron triathlon.

    Juan Del Coso

    Full Text Available BACKGROUND: To investigate the cause/s of muscle fatigue experienced during a half-iron distance triathlon. METHODOLOGY/PRINCIPAL FINDINGS: We recruited 25 trained triathletes (36±7 yr; 75.1±9.8 kg for the study. Before and just after the race, jump height and leg muscle power output were measured during a countermovement jump on a force platform to determine leg muscle fatigue. Body weight, handgrip maximal force and blood and urine samples were also obtained before and after the race. Blood myoglobin and creatine kinase concentrations were determined as markers of muscle damage. RESULTS: Jump height (from 30.3±5.0 to 23.4±6.4 cm; P0.05 but significantly correlated with myoglobin concentration (r = 0.65; P<0.001 and creatine kinase concentration (r = 0.54; P<0.001. CONCLUSIONS/SIGNIFICANCE: During a half-iron distance triathlon, the capacity of leg muscles to produce force was notably diminished while arm muscle force output remained unaffected. Leg muscle fatigue was correlated with blood markers of muscle damage suggesting that muscle breakdown is one of the most relevant sources of muscle fatigue during a triathlon.

  11. Effects of physical activity and inactivity on muscle fatigue

    GregoryC.Bogdanis

    2012-01-01

    The aim of this review was to examine the mechanisms by which physical activity and inactivity modify muscle fatigue. It is well known that acute or chronic increases in physical activity result in structural, metabolic, hormonal, neural and molecular adaptations that increase the level of force or power that can be sustained by a muscle. These adaptations depend on the type, intensity and volume of the exercise stimulus, but recent studies have highlighted the role of high intensity, short d...

  12. Effects of Physical Activity and Inactivity on Muscle Fatigue

    Bogdanis, Gregory C.

    2012-01-01

    The aim of this review was to examine the mechanisms by which physical activity and inactivity modify muscle fatigue. It is well known that acute or chronic increases in physical activity result in structural, metabolic, hormonal, neural, and molecular adaptations that increase the level of force or power that can be sustained by a muscle. These adaptations depend on the type, intensity, and volume of the exercise stimulus, but recent studies have highlighted the role of high intensity, short...

  13. SELECTIVE ACTIVATION OF THE RECTUS ABDOMINIS MUSCLE DURING LOW-INTENSITY AND FATIGUING TASKS

    Paulo H. Marchetti

    2011-06-01

    Full Text Available In order to understand the potential selective activation of the rectus abdominis muscle, we conducted two experiments. In the first, subjects performed two controlled isometric exercises: the curl up (supine trunk raise and the leg raise (supine bent leg raise at low intensity (in which only a few motor units are recruited. In the second experiment, subjects performed the same exercises, but they were required to maintain a certain force level in order to induce fatigue. We recorded the electromyographic (EMG activities of the lower and upper portions of the rectus abdominis muscle during the exercises and used spatial-temporal and frequency analyses to describe muscle activation patterns. At low-intensity contractions, the ratio between the EMG intensities of the upper and lower portions during the curl up exercise was significantly larger than during the leg raise exercise (p = 0.02. A cross-correlation analysis indicated that the signals of the abdominal portions were related to each other and this relation did not differ between the tasks (p = 0.12. In the fatiguing condition, fatigue for the upper portion was higher than for the lower portion during the curl up exercise (p = 0.008. We conclude that different exercises evoked, to a certain degree, individualized activation of each part of the rectus abdominis muscle, but different portions of the rectus abdominis muscle contributed to the same task, acting like a functional unit. These results corroborate the relevance of varying exercise to modify activation patterns of the rectus abdominis muscle

  14. Framework for Dynamic Evaluation of Muscle Fatigue in Manual Handling Work

    Ma, Liang; Bennis, Fouad; Chablat, Damien; Zhang, Wei

    2008-01-01

    Muscle fatigue is defined as the point at which the muscle is no longer able to sustain the required force or work output level. The overexertion of muscle force and muscle fatigue can induce acute pain and chronic pain in human body. When muscle fatigue is accumulated, the functional disability can be resulted as musculoskeletal disorders (MSD). There are several posture exposure analysis methods useful for rating the MSD risks, but they are mainly based on static postures. Even in some fati...

  15. Electromechanical delay of abdominal muscles is modified by low back pain prevention exercise.

    Szpala, Agnieszka; Rutkowska-Kucharska, Alicja; Drapala, Jaroslaw

    2014-01-01

    The objective of the research was to assess the effect of a 4-week-long training program on selected parameters: electromechanical delay (EMD) and amplitude of electromyographic signal (EMG). Fourteen female students of the University School of Physical Education participated in the study. Torques and surface electromyography were evaluated under static conditions. Surface electrodes were glued to both sides of the rectus abdominis (RA), external oblique (EO), and erector spinae (ES) muscles. The 4-week-long program was aimed at strengthening the abdominal muscles and resulted in increased EMD during maximum torque production by flexors of the trunk, increased amplitudes of the signals of the erector spinae ( p = 0.005), and increased EMG amplitude asymmetry of the lower ( p = 0.013) and upper part ( p = 0.006) of the rectus abdominis muscle. In a training program composed of a large number of repetitions of strength exercises, in which the training person uses their own weight as the load (like in exercises such as curl-ups), the process of recruitment of motor units is similar to that found during fatiguing exercises and plyometric training. PMID:25307027

  16. Intramuscular pressure, tissue oxygenation and EMG fatigue measured during isometric fatigue-inducing contraction of the multifidus muscle

    Kramer, M.; Dehner, C; Hartwig, E; Völker, H. U.; Sterk, J; Elbel, M.; Weikert, E.; Gerngroß, H; Kinzl, L.; Willy, C

    2005-01-01

    Simultaneous measurement of intramuscular pressure (IMP), tissue oxygen partial pressure (pO2) and EMG fatigue parameters in the multifidus muscle during a fatigue-inducing sustained muscular contraction. The study investigated the following hypotheses: (1) Increases in IMP result in tissue hypoxia; (2) Tissue hypoxia is responsible for loss of function in the musculature. The nutrient supply to muscle during muscle contraction is still not fully understood. It is assumed that muscle contract...

  17. Sildenafil increases muscle protein synthesis and reduces muscle fatigue

    SHEFFIELD-MOORE, M.; Wiktorowicz, J E; Soman, K V; Danesi, C.P.; Kinsky, M.P.; Dillon, E.L.; Randolph, K.M.; Casperson, S.L.; Gore, D.C.; Horstman, A.M.; Lynch, J. P.; Doucet, B.M.; Mettler, J.; Ryder, J W; Ploutz-Snyder, L.L.

    2013-01-01

    Reductions in skeletal muscle function occur during the course of healthy aging as well as with bedrest or diverse diseases such as cancer, muscular dystrophy, and heart failure. However, there are no accepted pharmacologic therapies to improve impaired skeletal muscle function. Nitric oxide may influence skeletal muscle function through effects on excitation-contraction coupling, myofibrillar function, perfusion, and metabolism. Here we show that augmentation of nitric oxide-cyclic guanosine...

  18. Effects of physical activity and inactivity on muscle fatigue

    Gregory C. Bogdanis

    2012-05-01

    Full Text Available The aim of this review was to examine the mechanisms by which physical activity and inactivity modify muscle fatigue. It is well known that acute or chronic increases in physical activity result in structural, metabolic, hormonal, neural and molecular adaptations that increase the level of force or power that can be sustained by a muscle. These adaptations depend on the type, intensity and volume of the exercise stimulus, but recent studies have highlighted the role of high intensity, short duration exercise as a time-efficient method to achieve both anaerobic and aerobic/endurance type adaptations. The factors that determine the fatigue profile of a muscle during intense exercise include muscle fibre composition, neuromuscular characteristics high energy metabolite stores, buffering capacity, ionic regulation, capillarization and mitochondrial density. Muscle fiber type transformation during exercise training is usually towards the intermediate type IIA at the expense of both type I and type IIx myosin heavy chain isoforms. High intensity training results in increases of both glycolyic and oxidative enzymes, muscle capilarization, improved phosphocreatine resynthesis and regulation of K+, H+ and lactate ions. Decreases of the habitual activity level due to injury or sedentary lifestyle result in partial or even compete reversal of the adaptations due to previous training, manifested by reductions in fibre cross-sectional area, decreased oxidative capacity and capillarization. Complete immobilization due to injury results in markedly decreased force output and fatigue resistance. Muscle unloading reduces electromyographic activity and causes muscle atrophy and significant decreases in capillarization and oxidative enzymes activity. The last part of the review discusses the beneficial effects of intermittent high intensity exercise training in patients with different health conditions to demonstrate the powerful effect exercise on health and well

  19. Changes in the flexion-relaxation response induced by hip extensor and erector spinae muscle fatigue

    Cantin Vincent; Lafond Danik; Descarreaux Martin

    2010-01-01

    Abstract Background The flexion-relaxation phenomenon (FRP) is defined by reduced lumbar erector spinae (ES) muscle myoelectric activity during full trunk flexion. The objectives of this study were to quantify the effect of hip and back extensor muscle fatigue on FRP parameters and lumbopelvic kinematics. Methods Twenty-seven healthy adults performed flexion-extension tasks under 4 different experimental conditions: no fatigue/no load, no fatigue/load, fatigue/no load, and fatigue/load. Total...

  20. Muscle Fatigue in the Temporal and Masseter Muscles in Patients with Temporomandibular Dysfunction

    Krzysztof Woźniak

    2015-01-01

    Full Text Available The aim of this study is to evaluate muscle fatigue in the temporal and masseter muscles in patients with temporomandibular dysfunction (TMD. Two hundred volunteers aged 19.3 to 27.8 years (mean 21.50, SD 0.97 participated in this study. Electromyographical (EMG recordings were performed using a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany. Muscle fatigue was evaluated on the basis of a maximum effort test. The test was performed during a 10-second maximum isometric contraction (MVC of the jaws. An analysis of changes in the mean power frequency of the two pairs of temporal and masseter muscles (MPF% revealed significant differences in the groups of patients with varying degrees of temporomandibular disorders according to Di (P<0.0000. The study showed an increase in the muscle fatigue of the temporal and masseter muscles correlated with the intensity of temporomandibular dysfunction symptoms in patients. The use of surface electromyography in assessing muscle fatigue is an excellent diagnostic tool for identifying patients with temporomandibular dysfunction.

  1. The multiple roles of phosphate in muscle fatigue

    DavidGrantAllen

    2012-12-01

    Full Text Available Muscle fatigue is the decline in performance of muscles observed during periods of intense activity. ATP consumption exceeds production during intense activity and there are multiple changes in intracellular metabolites which may contribute to the changes in crossbridge activity. It is also well-established that a reduction in activation, either through action potential changes or reduction in Ca2+ release from the sarcoplasmic reticulum (SR, makes an additional contribution to fatigue. In this review we focus on the role of intracellular inorganic phosphate (Pi whose concentration can increase rapidly from around 5 mM to 30 mM during intense fatigue. Studies from skinned muscle fibres show that these changes substantially impair myofibrillar performance although the effects are strongly temperature dependent. Increased Pi can also cause reduced Ca2+ release from the SR and may therefore contribute to the reduced activation. In a recent study, we have measured both Pi and Ca2+ release in a blood-perfused mammalian preparation and the results from this preparation allows us to test the extent to which the combined effects of Pi and Ca2+ changes may contribute to fatigue.

  2. A comparison of customized strategies to manage muscle fatigue in isometric artificially elicited muscle contractions for incomplete SCI subjects

    del-Ama Antonio J.; Koutsou Aikaterini D.; Bravo-Esteban Elisabeth; Gómez-Soriano Julio; Piazza Stefano; Gil-Agudo Ángel; Pons José L; Moreno Juan C

    2013-01-01

    Muscle fatigue due to functional electrical stimulation still prevents its widespread use as a gait rehabilitation tool for spinal cord injured subjects. Although there is an active research towards optimization of pulse parameters to delay muscle fatigue, changes in stimulated muscle's performance during repeated contractions due to fatigue have not been yet determined. In this work, a study conducted in two phases with a sample of incomplete spinal cord injured patients is presented. ...

  3. Neuromuscular activation strategies of voluntary andelectrically elicited muscle fatigue: Underlying mechanisms and clinicalimplications

    Doix, Aude-Clémence

    2013-01-01

    The clinical care of muscle fatigue with exercise therapies aim at quality of life improvement and usually involve unilateral exercises or neuromuscular electrical stimulation to compensate impaired muscle function in both healthy and health-compromised people. The overall objective of this thesis was to study the effect of neuromuscular activation strategies during muscle fatigue, endurance and muscle performance after unilateral fatiguing voluntary and electrically evoked contractions (NMES...

  4. Comparisons of changes in the two-point discrimination test following muscle fatigue in healthy adults

    Han, Jintae; Park, Soojin; Jung, Seonghyun; Choi, Yeounsung; Song, Hyunjoo

    2015-01-01

    [Purpose] This study aimed to examine the effects of muscle fatigue on skin sensation by looking at changes in two-point discrimination (2PD) after inducing muscle fatigue. [Subjects] Thirty-four young and healthy adults with no pathological symptoms (17 males; 17 females) participated in this study. [Methods] Continuous isometric contraction was applied to the upper and lower extremities with an intensity of 50% of the maximal muscle strength to trigger muscle fatigue, and then the 2PD test ...

  5. CORRELATIONS BETWEEN MUSCLE MASS, MUSCLE STRENGTH, PHYSICAL PERFORMANCE, AND MUSCLE FATIGUE RESISTANCE IN COMMUNITY-DWELLING ELDERLY SUBJECTS

    Dell, Elizabeth; Vitriana; Irma Ruslina Defi

    2016-01-01

    Objective: To determine the correlations between muscle mass, muscle strength, physical performance, and muscle fatigue resistance in community-dwelling elderly people in order to elucidate factors which contribute to elderly’s performance of daily activities. Methods: A cross-sectional study was conducted on community-dwelling elderly in Bandung from September to December 2014. One hundred and thirty elderly, 60 years old or above, were evaluated using bioelectrical impedance analysis to...

  6. Dynamic Muscle Fatigue Evaluation in Virtual Working Environment

    Ma, Liang; Chablat, Damien; Bennis, Fouad; Zhang, Wei

    2009-01-01

    Musculoskeletal disorder (MSD) is one of the major health problems in mechanical work especially in manual handling jobs. Muscle fatigue is believed to be the main reason for MSD. Posture analysis techniques have been used to expose MSD risks of the work, but most of the conventional methods are only suitable for static posture analysis. Meanwhile the subjective influences from the inspectors can result differences in the risk assessment. Another disadvantage is that the evaluation has to be ...

  7. Is Abdominal Muscle Activity Different from Lumbar Muscle Activity during Four-Point Kneeling?

    Soraya Pirouzi

    2013-12-01

    Full Text Available Background: Stabilization exercises can improve the performance of trunk and back muscles, which are effective in the prevention and treatment of low back pain. The four-point kneeling exercise is one of the most common types of stabilization exercises. This quasi-experimental study aimed to evaluate and compare the level of activation between abdominal and lumbar muscles in the different stages of the four-point kneeling exercise. Methods: The present study was conducted on 30 healthy women between 20 and 30 years old. Muscle activity was recorded bilaterally from transversus abdominis, internal oblique, and multifidus muscles with an electromyography (EMG device during the different stages of the four-point kneeling exercise. All the collected EMG data were normalized to the percentage of maximum voluntary isometric contraction. The repeated measures ANOVA and paired t-test were used for the statistical analysis of the data. Results: A comparison between mean muscle activation in right arm extension and left leg extension showed that left internal oblique and left transverse abdominis muscles produced greater activation during left leg extension (P<0.05. The comparison of mean muscle activation between right arm extension and the bird-dog position showed that, except for the right internal oblique, all the muscles produced higher activation in the bird-dog stage (P<0.05. In comparison to the bird-dog stage, the left multifidus showed high activation during left leg extension (P<0.05. Conclusion: The results of this study showed that the activity of all the above-mentioned muscles during quadruped exercise can provide stability, coordination, and smoothness of movements.

  8. POSTOPERATIVE RECOVERY OF MUSCLE FORCE THROUGH MUSCLE TONING IN ABDOMINAL PARIETAL DEFECTS

    Gabriela Monica Moacă

    2015-10-01

    Full Text Available The present paper’s aim is to elaborate a program of postoperative recovery for patients suffering from abdominal parietal defects, and to indicate the beneficial implications, both of the preoperative preparations and of the postoperative physiotherapist actions. The programs of functional postoperative recovery have been elaborated individually for the 254 patients under study – of which 139 belong to lot A (operated under a scheduled regime, after the preoperative preparation and 115 belong to lot B (operated in an emergency regime, in the General Surgery Clinic III of the University Emergency Hospital of Bucharest, between 1998 and 2009. The postoperative recovery program has been individualized for each patient, depending on his / her pathology and co-morbidities, and the physiotherapist has trained and took care that the patients should execute exercises of respiratory re-education, active mobilization of their limbs, coordinated with the breath, isometric exercises for the toning of their arms and legs and of the abdomen muscles. They started the muscle toning exercises slowly and increased them progressively in duration and intensity. The recovery started with isometric-type exercises and continued with the isotonic-type ones. Though mainly the abdominal muscles are aimed at, respectively the flexor muscles of the torso, the physiotherapy program shall comprise the toning of the other muscle groups of the torso, as well. It has been noticed - for the patients in lot A, compared to those of lot B - an obvious net favorable postoperative evolution, characterized through: a reduction of the respiratory, cardiac and thromboembolic complications, a quick postoperative recovery and the immediate social reintegration. An overview of the two lots proves the importance of the cardio-respiratory and locomotive preparation of the patients suffering from big abdominal parietal defects. The simple gestures of respiratory re-education, of

  9. Intercostal and forearm muscle deoxygenation during respiratory fatigue in patients with heart failure: potential role of a respiratory muscle metaboreflex

    Moreno, A. M.; R.R.T. de Castro; Silva, B. M.; Villacorta, H; M. Sant'Anna Junior; Nóbrega, A.C.L.

    2014-01-01

    The purpose of this study was to determine the effect of respiratory muscle fatigue on intercostal and forearm muscle perfusion and oxygenation in patients with heart failure. Five clinically stable heart failure patients with respiratory muscle weakness (age, 66±12 years; left ventricle ejection fraction, 34±3%) and nine matched healthy controls underwent a respiratory muscle fatigue protocol, breathing against a fixed resistance at 60% of their maximal inspiratory pressure for as long as th...

  10. Sphingomyelinase stimulates oxidant signaling to weaken skeletal muscle and promote fatigue

    Ferreira, Leonardo F; Moylan, Jennifer S.; Gilliam, Laura A.A.; Smith, Jeffrey D.; Nikolova-Karakashian, Mariana; Reid, Michael B.

    2010-01-01

    Sphingomyelinase (SMase) hydrolyzes membrane sphingomyelin into ceramide, which increases oxidants in nonmuscle cells. Serum SMase activity is elevated in sepsis and heart failure, conditions where muscle oxidants are increased, maximal muscle force is diminished, and fatigue is accelerated. We tested the hypotheses that exogenous SMase and accumulation of ceramide in muscle increases oxidants in muscle cells, depresses specific force of unfatigued muscle, and accelerates the fatigue process....

  11. Enhanced muscle fatigue occurs in male but not female ASIC3-/- mice

    Burnes, Lynn A.; Kolker, Sandra J.; Danielson, Jessica F.; Walder, Roxanne Y.; Sluka, Kathleen A.

    2008-01-01

    Muscle fatigue is associated with a number of clinical diseases, including chronic pain conditions. Decreases in extracellular pH activates acid-sensing ion channel 3 (ASIC3), depolarizes muscle, protects against fatigue, and produces pain. We examined whether ASIC3-/- mice were more fatigable than ASIC3+/+ mice in a task-dependent manner. We developed two exercise protocols to measure exercise-induced muscle fatigue: ( fatigue task 1, three 1-h runs; fatigue task 2, three 30-min runs). In fa...

  12. Muscle fatigue evaluation of astronaut upper limb based on sEMG and subjective assessment

    Zu, Xiaoqi; Zhou, Qianxiang; Li, Yun

    2012-07-01

    All movements are driven by muscle contraction, and it is easy to cause muscle fatigue. Evaluation of muscle fatigue is a hot topic in the area of astronaut life support training and rehabilitation. If muscle gets into fatigue condition, it may reduce work efficiency and has an impact on psychological performance. Therefore it is necessary to develop an accurate and usable method on muscle fatigue evaluation of astronaut upper limb. In this study, we developed a method based on surface electromyography (sEMG) and subjective assessment (Borg scale) to evaluate local muscle fatigue. Fifteen healthy young male subjects participated in the experiment. They performed isometric muscle contractions of the upper limb. sEMG of the biceps brachii were recorded during the entire process of isotonic muscle contraction and Borg scales of muscle fatigue were collected in certain times. sEMG were divided into several parts, and then mean energy of each parts were calculated by the one-twelfth band octave method. Equations were derived based on the relationship between the mean energy of sEMG and Borg scale. The results showed that cubic curve could describe the degree of local muscle fatigue, and could be used to evaluate and monitor local muscle fatigue during the entire process.

  13. Fatigue alters in vivo function within and between limb muscles during locomotion

    Biewener, Andrew A.; Higham, Timothy E.

    2008-01-01

    Muscle fatigue, a reduction in force as a consequence of exercise, is an important factor for any animal that moves, and can result from both peripheral and/or central mechanisms. Although much is known about whole-limb force generation and activation patterns in fatigued muscles under sustained isometric contractions, little is known about the in vivo dynamics of limb muscle function in relation to whole-body fatigue. Here we show that limb kinematics and contractile function in the lateral ...

  14. A Laboratory Experiment on Muscular Metabolism and Fatigue Using the Isolated Frog Muscle Preparation.

    Ianuzzo, C. David; And Others

    1987-01-01

    Describes an experiment which demonstrates the association of particular metabolic biochemical changes and muscular fatigue. Highlights applications related to cellular energy metabolism, metabolic regulation, and muscle energetics. (ML)

  15. The Effects of Deep Abdominal Muscle Strengthening Exercises on Respiratory Function and Lumbar Stability

    Kim, Eunyoung; Lee, Hanyong

    2013-01-01

    [Purpose] The purpose of this study was to examine the effects of deep abdominal muscle strengthening exercises on respiratory function and lumbar stability. [Subjects] From among 120 male and female students, 22 whose thoraxes opened no more than 5 cm during inspiration and expiration and whose forced expiratory flow rates were around 300 m/L were recruited. The subjects were randomly divided into an experimental group of eleven, who performed deep abdominal muscle strengthening exercises, a...

  16. Fatigue-enhanced hyperalgesia in response to muscle insult: induction and development occur in a sex-dependent manner

    Gregory, N. S.; Gibson-Corley, K.; Frey-Law, L.; Sluka, K. A.

    2013-01-01

    Chronic muscle pain affects 20–50% of the population, is more common in women than men, and is associated with increased pain during physical activity and exercise. Muscle fatigue is common in people with chronic muscle pain, occurs in response to exercise and is associated with release of fatigue metabolites. Fatigue metabolites can sensitize muscle nociceptors which could enhance pain with exercise. Using a mouse model we tested whether fatigue of a single muscle, induced by electrical stim...

  17. Systematic Review and Meta-Analysis of Skeletal Muscle Fatigue in Old Age

    Christie, Anita; SNOOK, ERIN M.; Kent-Braun, Jane A.

    2011-01-01

    Despite intense interest in understanding how old age may alter skeletal muscle fatigability, a quantitative examination of the impact of study design on age-related differences in muscle fatigue does not exist.

  18. Quadriceps femoris muscle fatigue in patients with knee osteoarthritis

    Elboim-Gabyzon M; Rozen N; Laufer Y

    2013-01-01

    M Elboim-Gabyzon,1 N Rozen,2 Y Laufer11Physical Therapy Department, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel; 2Emek Medical Center, Afula, IsraelAbstract: The purpose of this study was to characterize quadriceps femoris muscle fatigue of both lower extremities in patients with knee osteoarthritis (OA). Sixty-two subjects (mean age 68.2 years, standard deviation [SD] ± 7.9 years) with knee OA participated in the study. Significantly higher knee p...

  19. Direct measurement of skeletal muscle fatigue in patients with chronic heart failure.

    Buller, N. P.; Jones, D.; Poole-Wilson, P A

    1991-01-01

    Skeletal muscle function was measured as force production and fatigue in both the quadriceps (a large locomotive muscle) and adductor pollicis (a small intrinsic hand muscle) in five healthy volunteers, five patients with mild chronic heart failure, and five patients with severe chronic heart failure. The quadriceps of patients with chronic heart failure had a reduced muscle cross sectional area, a reduced maximum isometric force production, and an increased tendency to fatigue. Isometric for...

  20. Effects of stimulation frequency versus pulse duration modulation on muscle fatigue

    Kesar, Trisha; Chou, Li-Wei; Binder-Macleod, Stuart A.

    2007-01-01

    During functional electrical stimulation (FES), both the frequency and intensity can be increased to increase muscle force output and counteract the effects of muscle fatigue. Most current FES systems, however, deliver a constant frequency and only vary the stimulation intensity to control muscle force. This study compared muscle performance and fatigue produced during repetitive electrical stimulation using three different strategies: (1) constant pulse-duration and stepwise increases in fre...

  1. Changes in joint coupling and variability during walking following tibialis posterior muscle fatigue

    Ferber Reed; Pohl Michael B

    2011-01-01

    Abstract Background The tibialis posterior muscle is believed to play a key role in controlling foot mechanics during the stance phase of gait. However, an experiment involving localised tibialis posterior muscle fatigue, and analysis of discrete rearfoot and forefoot kinematic variables, indicated that reduced force output of the tibialis posterior muscle did not alter rearfoot and forefoot motion during gait. Thus, to better understand how muscle fatigue affects foot kinematics and injury p...

  2. An oblique muscle hematoma as a rare cause of severe abdominal pain: a case report

    Shimodaira Masanori

    2013-01-01

    Full Text Available Abstract Background Abdominal wall hematomas are an uncommon cause of acute abdominal pain and are often misdiagnosed. They are more common in elderly individuals, particularly in those under anticoagulant therapy. Most abdominal wall hematomas occur in the rectus sheath, and hematomas within the oblique muscle are very rare and are poorly described in the literature. Here we report the case of an oblique muscle hematoma in a middle-aged patient who was not under anticoagulant therapy. Case presentation A 42-year-old Japanese man presented with a painful, enlarging, lateral abdominal wall mass, which appeared after playing baseball. Abdominal computed tomography and ultrasonography showed a large soft tissue mass located in the patient’s left internal oblique muscle. A diagnosis of a lateral oblique muscle hematoma was made and the patient was treated conservatively. Conclusion Physicians should consider an oblique muscle hematoma during the initial differential diagnosis of pain in the lateral abdominal wall even in the absence of anticoagulant therapy or trauma.

  3. Quantitation of progressive muscle fatigue during dynamic leg exercise in humans

    Fulco, C S; Lewis, S F; Frykman, Peter; Boushel, Robert Christopher; Smith, Susanne; Harman, E A; Cymerman, A; Pandolf, K B

    1995-01-01

    There is virtually no published information on muscle fatigue, defined as a gradual decline in force-generating capacity, during conventional dynamic (D) leg exercise. To quantitate progression of fatigue, we developed 1) a model featuring integration of maximal voluntary static contraction (MVC)...... interventions on the fatigue process and may permit unique insights into the involved mechanisms....

  4. Effect of acetazolamide on respiratory muscle fatigue in humans.

    Gonzales, Joaquin U; Scheuermann, Barry W

    2013-01-15

    Previous studies have demonstrated that carbonic anhydrase inhibition with acetazolamide reduces exercise capacity. The mechanism responsible for this early fatigue is unclear, but may be partly mediated by impaired respiratory muscle function. Inspiratory muscle strength and endurance were assessed in seven healthy men (age 28 ± 5 yrs, ±SD) by measuring maximal inspiratory pressure (MIP) and time to task failure during a constant-load breathing test (CLBT), respectively, under control (CON) and acetazolamide (ACZ; 500 mg/8 h po for 3 days) conditions that were separated by two weeks and randomized between subjects. In addition, MIP was measured before and after moderate-intensity cycling exercise to fatigue while pulmonary gas exchange, plasma pH, and ventilation were measured during exercise. ACZ did not alter pulmonary function (FVC, FEV1, MVV) or MIP measured at rest (CON, -157 ± 47 vs. ACZ, -154 ± 45 cmH(2)O, p>0.05), but decreased time to task failure during the CLBT (CON, 1340 ± 820 vs. ACZ, 698 ± 434 s; p=0.01). Exercise duration during cycling exercise was reduced (p=0.003) with ACZ (1090 ± 254 s) compared to CON (1944 ± 532 s) in the presence of a significantly lower plasma pH and higher ventilation compared to control (ptolerance with carbonic anhydrase inhibition. PMID:23017330

  5. An Autonomous Wearable System for Predicting and Detecting Localised Muscle Fatigue

    Martin Colley,; Al-Mulla, Mohamed R.; Francisco Sepulveda

    2011-01-01

    Muscle fatigue is an established area of research and various types of muscle fatigue have been clinically investigated in order to fully understand the condition. This paper demonstrates a non-invasive technique used to automate the fatigue detection and prediction process. The system utilises the clinical aspects such as kinematics and surface electromyography (sEMG) of an athlete during isometric contractions. Various signal analysis methods are used illustrating their applicability in rea...

  6. A Review of Non-Invasive Techniques to Detect and Predict Localised Muscle Fatigue

    Al-Mulla, Mohamed R.; Martin Colley,; Francisco Sepulveda

    2011-01-01

    Muscle fatigue is an established area of research and various types of muscle fatigue have been investigated in order to fully understand the condition. This paper gives an overview of the various non-invasive techniques available for use in automated fatigue detection, such as mechanomyography, electromyography, near-infrared spectroscopy and ultrasound for both isometric and non-isometric contractions. Various signal analysis methods are compared by illustrating their applicability in real-...

  7. Multifractal analysis of surface EMG signals for assessing muscle fatigue during static contractions

    WANG Gang; REN Xiao-mei; LI Lei; WANG Zhi-zhong

    2007-01-01

    This study is aimed at assessing muscle fatigue during a static contraction using multifractal analysis and found that the surface electromyographic (SEMG) signals characterized multifractality during a static contraction. By applying the method of direct determination of the f(α) singularity spectrum, the area of the multifractal spectrum of the SEMG signals was computed. The results showed that the spectrum area significantly increased during muscle fatigue. Therefore the area could be used as an assessor of muscle fatigue. Compared with the median frequency (MDF)-the most popular indicator of muscle fatigue, the spectrum area presented here showed higher sensitivity during a static contraction. So the singularity spectrum area is considered to be a more effective indicator than the MDF for estimating muscle fatigue.

  8. Consequences of lower extremity and trunk muscle fatigue on balance and functional tasks in older people: A systematic literature review

    Helbostad Jorunn L; Sturnieks Daina L; Menant Jasmine; Delbaere Kim; Lord Stephen R; Pijnappels Mirjam

    2010-01-01

    Abstract Background Muscle fatigue reduces muscle strength and balance control in young people. It is not clear whether fatigue resistance seen in older persons leads to different effects. In order to understand whether muscle fatigue may increase fall risk in older persons, a systematic literature review aimed to summarize knowledge on the effects of lower extremity and trunk muscle fatigue on balance and functional tasks in older people was performed. Methods Studies were identified with se...

  9. Comparison of changes in the mobility of the pelvic floor muscle on during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction

    Jung, Halim; Jung, SangWoo; Joo, Sunghee; Song, Changho

    2016-01-01

    [Purpose] The purpose of this study was to compare changes in the mobility of the pelvic floor muscle during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. [Subjects] Thirty healthy adults participated in this study (15 men and 15 women). [Methods] All participants performed a bridge exercise and abdominal curl-up during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. Pelvic floor mobility...

  10. Comparison of changes in the contraction of the lateral abdominal muscles between the abdominal drawing-in maneuver and breathe held at the maximum expiratory level.

    Ishida, Hiroshi; Hirose, Ryohei; Watanabe, Susumu

    2012-10-01

    The abdominal drawing-in maneuver (ADIM) is commonly used as a fundamental component of lumbar stabilization training programs. One potential limitation of lumbar stabilization programs is that it can be difficult and time consuming to train people to perform the ADIM. The transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles are the most powerful muscles involved in expiration. However, little is known about the differences in the recruitment of the abdominal muscles between the ADIM and breathe held at maximum expiratory level (maximum expiration). The thickness of the TrA and IO muscles was measured by ultrasound imaging, and the activity of the EO muscle was measured by electromyography (EMG) in 33 healthy male performing the ADIM and maximum expiration. Maximum expiration produced a significant increase in the thickness of the TrA and IO muscles compared to the ADIM (p method for training of co-activation of the lateral abdominal muscles. PMID:22595657

  11. Use of muscle synergies and wavelet transforms to identify fatigue during squatting.

    Smale, Kenneth B; Shourijeh, Mohammad S; Benoit, Daniel L

    2016-06-01

    The objective of this study was to supplement continuous wavelet transforms with muscle synergies in a fatigue analysis to better describe the combination of decreased firing frequency and altered activation profiles during dynamic muscle contractions. Nine healthy young individuals completed the dynamic tasks before and after they squatted with a standard Olympic bar until complete exhaustion. Electromyography (EMG) profiles were analyzed with a novel concatenated non-negative matrix factorization method that decomposed EMG signals into muscle synergies. Muscle synergy analysis provides the activation pattern of the muscles while continuous wavelet transforms output the temporal frequency content of the EMG signals. Synergy analysis revealed subtle changes in two-legged squatting after fatigue while differences in one-legged squatting were more pronounced and included the shift from a general co-activation of muscles in the pre-fatigue state to a knee extensor dominant weighting post-fatigue. Continuous wavelet transforms showed major frequency content decreases in two-legged squatting after fatigue while very few frequency changes occurred in one-legged squatting. It was observed that the combination of methods is an effective way of describing muscle fatigue and that muscle activation patterns play a very important role in maintaining the overall joint kinetics after fatigue. PMID:27156237

  12. Muscle activity, time to fatigue, and maximum task duration at different levels of production standard time

    Nur, Nurhayati Mohd; Dawal, Siti Zawiah Md; Dahari, Mahidzal; Sanusi, Junedah

    2015-01-01

    [Purpose] This study investigated the variations in muscle fatigue, time to fatigue, and maximum task duration at different levels of production standard time. [Methods] Twenty subjects performed repetitive tasks at three different levels of production standard time corresponding to “normal”, “hard” and “very hard”. Surface electromyography was used to measure the muscle activity. [Results] The results showed that muscle activity was significantly affected by the production standard time leve...

  13. Effects of Aerobic Exercise on Abdominal Fat, Thigh Muscle Mass and Muscle Strength in Type 2 Diabetic Subject

    Kwon, Hwi Ryun; Min, Kyung Wan; Ahn, Hee Jung; Seok, Hee Geum; Koo, Bo Kyung; Kim, Ho Chul; Han, Kyung Ah

    2010-01-01

    Background Aerobic exercise can effectively reduce visceral fat. However, few studies have examined the effect of daily physical activity on obesity and cardiopulmonary function in the subjects with diabetes. We examined the effect of moderate intensity of walking in obese diabetes patients by monitoring of daily activity and measuring the change in abdominal fat area, muscle are and maximal muscle strength. Methods We randomly assigned 27 obese women with type 2 diabetes to an aerobic exerci...

  14. Comparison of Contraction Rates of Abdominal Muscles of Chronic Low Back Pain Patients in Different Postures

    Cho, Sung-Hak; Kim, Kang Hoon; Baek, Il-Hun; Goo, Bong-Oh

    2013-01-01

    [Purpose] This study examined the contraction rates of abdominal muscles in relation to the posture of chronic lumbar pain patients and normal subjects. [Subjects] The subjects were 17 chronic low back pain (CLBP) patients and 17 normal people between the ages of 20 and 59. [Methods] Experimental postures included a supine position, a sitting position, and a standing position. Measurements were taken at rest and during abdominal contraction. The measurement at rest was taken during expiration...

  15. An Autonomous Wearable System for Predicting and Detecting Localised Muscle Fatigue

    Martin Colley

    2011-01-01

    Full Text Available Muscle fatigue is an established area of research and various types of muscle fatigue have been clinically investigated in order to fully understand the condition. This paper demonstrates a non-invasive technique used to automate the fatigue detection and prediction process. The system utilises the clinical aspects such as kinematics and surface electromyography (sEMG of an athlete during isometric contractions. Various signal analysis methods are used illustrating their applicability in real-time settings. This demonstrated system can be used in sports scenarios to promote muscle growth/performance or prevent injury. To date, research on localised muscle fatigue focuses on the clinical side and lacks the implementation for detecting/predicting localised muscle fatigue using an autonomous system. Results show that automating the process of localised muscle fatigue detection/prediction is promising. The autonomous fatigue system was tested on five individuals showing 90.37% accuracy on average of correct classification and an error of 4.35% in predicting the time to when fatigue will onset.

  16. Changes in Activation of Abdominal Muscles at Selected Angles During Trunk Exercise by Using Ultrasonography

    Kim, Hyun-Dong; Bae, Hyun-Woo; Kim, Jong-Gil; Han, Nami; Eom, Mi-Ja

    2015-01-01

    Objective To investigate the changes of activation of the abdominal muscles depending on exercise angles and whether the activation of rectus abdominis differs according to the location, during curl up and leg raise exercises, by measuring the thickness ratio of abdominal muscles using ultrasonography. Methods We examined 30 normal adults without musculoskeletal problems. Muscle thickness was measured in the upper rectus abdominis (URA), lower rectus abdominis (LRA), obliquus externus (EO), obliquus internus (IO), and transversus abdominis (TrA), at pre-determined angles (30°, 60°, 90°) and additionally at the resting angle (0°). Muscle thickness ratio was calculated by dividing the resting (0°) thickness for each angle, and was used as reflection of muscle activity. Results The muscle thickness ratio was significantly different depending on the angles in URA and LRA. For curl up-URA p=0 (30°90°), p=0.44 (30°90°), p=0.44 (30°>90°), respectively, by one-way ANOVA test-and for leg raise-URA p=0 (30°<60°), p=0 (60°<90°), p=0 (30°<90°) and LRA p=0.01 (30°<60°), p=0 (60°<90°), p=0 (30°<90°), respectively, by one-way ANOVA test-exercises, but not in the lateral abdominal muscles (EO, IO, and TrA). Also, there was no significant difference in the muscle thickness ratio of URA and LRA during both exercises. In the aspect of muscle activity, there was significant difference in the activation of RA muscle by selected angles, but not according to location during both exercises. Conclusion According to this study, exercise angle is thought to be an important contributing factor for strengthening of RA muscle; however, both the exercises are thought to have no property of strengthening RA muscle selectively based on the location. PMID:26798609

  17. Core muscle size assessed by perioperative abdominal CT scan is related to mortality, postoperative complications, and hospitalization after major abdominal surgery

    Hasselager, Rune; Gögenur, Ismail

    2014-01-01

    systematically review the literature where core muscle size measurements have been used for risk assessment of patients undergoing major abdominal surgery. METHODS: PubMed and EMBASE databases were searched for studies that investigated core muscle size measured with abdominal CT scans and outcomes after major...... abdominal surgery. RESULTS: Eight studies were found. Four studies investigated postoperative complications related to core muscle area. Three of these studies found significantly increased risk of complications related to low core muscle area. Three studies investigated length of hospitalization, and two...... of these found significantly longer length of stay related to low core muscle area. Seven studies investigated 1-year and long-term mortality after surgery, whereof only one did not find significantly increased mortality related to low core muscle area. Furthermore, one study found increased short...

  18. Wet, volatile, and dry biomarkers of exercise-induced muscle fatigue

    Finsterer, Josef; Drory, Vivian E

    2016-01-01

    Background The physiological background of exercise-induced muscle fatigue(EIMUF) is only poorly understood. Thus, monitoring of EIMUF by a single or multiple biomarkers(BMs) is under debate. After a systematic literature review 91 papers were included. Results EIMUF is mainly due to depletion of substrates, increased oxidative stress, muscle membrane depolarisation following potassium depletion, muscle hyperthermia, muscle damage, impaired oxygen supply to the muscle, activation of an inflam...

  19. Effects of Kinesio taping on scapular kinematics of overhead athletes following muscle fatigue.

    Zanca, Gisele Garcia; Grüninger, Bruno; Mattiello, Stela Márcia

    2016-08-01

    Scapular kinematics alterations have been found following muscle fatigue. Considering the importance of the lower trapezius in coordinated scapular movement, this study aimed to investigate the effects of elastic taping (Kinesio taping, KT) for muscle facilitation on scapular kinematics of healthy overhead athletes following muscle fatigue. Twenty-eight athletes were evaluated in a crossover, single-blind, randomized design, in three sessions: control (no taping), KT (KT with tension) and sham (KT without tension). Scapular tridimensional kinematics and EMG of clavicular and acromial portions of upper trapezius, lower trapezius and serratus anterior were evaluated during arm elevation and lowering, before and after a fatigue protocol involving repetitive throwing. Median power frequency decline of serratus anterior was significantly lower in KT session compared to sham, possibly indicating lower muscle fatigue. However, the effects of muscle fatigue on scapular kinematics were not altered by taping conditions. Although significant changes were found in scapular kinematics following muscle fatigue, they were small and not considered relevant. It was concluded that healthy overhead athletes seem to present an adaptive mechanism that avoids the disruption of scapular movement pattern following muscle fatigue. Therefore, these athletes do not benefit from the use of KT to assist scapular movement under the conditions tested. PMID:26149961

  20. Changes in the flexion relaxation response induced by lumbar muscle fatigue

    Cantin Vincent

    2008-01-01

    Full Text Available Abstract Background The flexion relaxation phenomenon (FRP is an interesting model to study the modulation of lumbar stability. Previous investigations have explored the effect of load, angular velocity and posture on this particular response. However, the influence of muscular fatigue on FRP parameters has not been thoroughly examined. The objective of the study is to identify the effect of erector spinae (ES muscle fatigue and spine loading on myoelectric silence onset and cessation in healthy individuals during a flexion-extension task. Methods Twenty healthy subjects participated in this study and performed blocks of 3 complete trunk flexions under 4 different experimental conditions: no fatigue/no load (1, no fatigue/load (2, fatigue/no load(3, and fatigue/load (4. Fatigue was induced according to the Sorenson protocol, and electromyographic (EMG power spectral analysis confirmed that muscular fatigue was adequate in each subject. Trunk and pelvis angles and surface EMG of the ES L2 and L5 were recorded during a flexion-extension task. Trunk flexion angle corresponding to the onset and cessation of myoelectric silence was then compared across the different experimental conditions using 2 × 2 repeated-measures ANOVA. Results Onset of myoelectric silence during the flexion motion appeared earlier after the fatigue task. Additionally, the cessation of myoelectric silence was observed later during the extension after the fatigue task. Statistical analysis also yielded a main effect of load, indicating a persistence of ES myoelectric activity in flexion during the load condition. Conclusion The results of this study suggest that the presence of fatigue of the ES muscles modifies the FRP. Superficial back muscle fatigue seems to induce a shift in load-sharing towards passive stabilizing structures. The loss of muscle contribution together with or without laxity in the viscoelastic tissues may have a substantial impact on post fatigue stability.

  1. Recruitment and plasticity in diaphragm, intercostal, and abdominal muscles in unanesthetized rats

    Navarrete-Opazo, A.; Mitchell, G.S.

    2014-01-01

    Although rats are a frequent model for studies of plasticity in respiratory motor control, the relative capacity of rat accessory respiratory muscles to express plasticity is not well known, particularly in unanesthetized animals. Here, we characterized external intercostal (T2, T4, T5, T6, T7, T8, T9 EIC) and abdominal muscle (external oblique and rectus abdominis) electromyogram (EMG) activity in unanesthetized rats via radiotelemetry during normoxia (Nx: 21% O2) and following acute intermi...

  2. Shoulder girdle muscle activity and fatigue in traditional and improved design carpet weaving workstations

    Teimour Allahyari

    2016-04-01

    Full Text Available Objectives: Work-related musculoskeletal disorders in the neck and shoulder regions are common among carpet weavers. Working for prolonged hours in a static and awkward posture could result in an increased muscle activity and may lead to musculoskeletal disorders. Ergonomic workstation improvements can reduce muscle fatigue and the risk of musculoskeletal disorders. Material and Methods: The aim of this study is to assess and to compare upper trapezius and middle deltoid muscle activity in 2 traditional and improved design carpet weaving workstations. These 2 workstations were simulated in a laboratory and 12 women carpet weavers worked for 3 h. Electromyography (EMG signals were recorded during work in bilateral upper trapezius and bilateral middle deltoid. The root mean square (RMS and median frequency (MF values were calculated and used to assess muscle load and fatigue. Repeated measure ANOVA was performed to assess the effect of independent variables on muscular activity and fatigue. The participants were asked to report shoulder region fatigue on the Borg’s Category-Ratio scale (Borg CR-10. Results: Root mean square values in workstation A are significantly higher than in workstation B. Furthermore, EMG amplitude was higher in bilateral trapezius than in bilateral deltoid. However, muscle fatigue was not observed in any of the workstations. Conclusions: The results of the study revealed that muscle load in a traditional workstation was high, but fatigue was not observed. Further studies investigating other muscles involved in carpet weaving tasks are recommended.

  3. Novel Feature Modelling the Prediction and Detection of sEMG Muscle Fatigue towards an Automated Wearable System

    Al-Mulla, Mohamed R.; Francisco Sepulveda

    2010-01-01

    Surface Electromyography (sEMG) activity of the biceps muscle was recorded from ten subjects performing isometric contraction until fatigue. A novel feature (1D spectro_std) was used to extract the feature that modeled three classes of fatigue, which enabled the prediction and detection of fatigue. Initial results of class separation were encouraging, discriminating between the three classes of fatigue, a longitudinal classification on Non-Fatigue and Transition-to-Fatigue shows 81.58% correc...

  4. Fatigue-induced Orosomucoid 1 Acts on C-C Chemokine Receptor Type 5 to Enhance Muscle Endurance

    Hong Lei; Yang Sun; Zhumin Luo; Gregory Yourek; Huan Gui; Yili Yang; Ding-Feng Su; Xia Liu

    2016-01-01

    Understanding and managing fatigue is a significant challenge in clinic and society. In attempting to explore how the body responds to and regulates fatigue, we found in rodent fatigue models that orosomucoid 1 (ORM1) was significantly increased in multiple tissues, including blood and muscle. Interestingly, administration of exogenous ORM1 increased muscle glycogen and enhanced muscle endurance, whereas ORM1 deficiency resulted in a significant decrease of muscle endurance both in vivo and i...

  5. Uncommon abdominal muscle injury in a tennis player: internal oblique strain

    Maquirriain, J; Ghisi, J P

    2006-01-01

    The case of a strain injury of the internal oblique abdominal muscle in a professional tennis player is presented. This uncommon lesion resulted from eccentric, unbalanced trunk rotation. Magnetic resonance imaging helped to confirm the diagnosis. Tennis specific core strengthening is crucial for rehabilitation and recurrence prevention.

  6. Muscle Fatigue Tracking Based on Stimulus Evoked EMG and Adaptive Torque Prediction

    Zhang, Qin; Hayashibe, Mitsuhiro; Guiraud, David

    2011-01-01

    Functional electrical stimulation (FES) is effective to restore movement in spinal cord injured (SCI) subjects. Unfortunately, muscle fatigue constrains the application of FES so that output torque feedback is interesting for fatigue compensation. Whereas, inadequacy of torque sensors is another challenge for FES control. Torque estimation is thereby essential in fatigue tracking task for practical FES employment. In this work, the Hammstein cascade with electromyography (EMG) as input is app...

  7. Changes in joint coupling and variability during walking following tibialis posterior muscle fatigue

    Ferber Reed

    2011-02-01

    Full Text Available Abstract Background The tibialis posterior muscle is believed to play a key role in controlling foot mechanics during the stance phase of gait. However, an experiment involving localised tibialis posterior muscle fatigue, and analysis of discrete rearfoot and forefoot kinematic variables, indicated that reduced force output of the tibialis posterior muscle did not alter rearfoot and forefoot motion during gait. Thus, to better understand how muscle fatigue affects foot kinematics and injury potential, the purpose of this study was to reanalyze the data and investigate shank, rearfoot and forefoot joint coupling and coupling variability during walking. Methods Twenty-nine participants underwent an exercise fatigue protocol aimed at reducing the force output of tibialis posterior. An eight camera motion analysis system was used to evaluate 3 D shank and foot joint coupling and coupling variability during treadmill walking both pre- and post-fatigue. Results The fatigue protocol was successful in reducing the maximal isometric force by over 30% and a concomitant increase in coupling motion of the shank in the transverse plane and forefoot in the sagittal and transverse planes relative to frontal plane motion of the rearfoot. In addition, an increase in joint coupling variability was measured between the shank and rearfoot and between the rearfoot and forefoot during the fatigue condition. Conclusions The reduced function of the tibialis posterior muscle following fatigue resulted in a disruption in typical shank and foot joint coupling patterns and an increased variability in joint coupling. These results could help explain tibialis posterior injury aetiology.

  8. Matching initial torque with different stimulation parameters influences skeletal muscle fatigue

    C. Scott Bickel, PT, PhD; Chris M. Gregory, PT, PhD; Andres Azuero, PhD

    2012-01-01

    A fundamental barrier to using electrical stimulation in the clinical setting is an inability to maintain torque production secondary to muscle fatigue. Electrical stimulation parameters are manipulated to influence muscle torque production, and they may also influence fatigability during repetitive stimulation. Our purpose was to determine the response of the quadriceps femoris to three different fatigue protocols using the same initial torque obtained by altering stimulator parameter settin...

  9. Depression of corticomotor excitability after muscle fatigue induced by electrical stimulation and voluntary contraction

    Shinichi Kotan

    2015-01-01

    In this study, we examined the effect of muscle fatigue induced by tetanic electrical stimulation (ES) and submaximal isometric contraction on corticomotor excitability. Experiments were performed in a cross-over design. Motor-evoked potentials (MEPs) were elicited by transcranial magnetic stimulation (TMS). Corticomotor excitability was recorded before and after thumb opposition muscle fatigue tasks, in which 10% of the maximal tension intensity was induced by tetanic ES or voluntary contrac...

  10. Determine the effect of neck muscle fatigue on dynamic visual acuity in healthy young adults

    Al Saif, Amer A.; Al Senany, Samira

    2015-01-01

    [Purpose] The aim of this study was to determine whether neck muscle fatigue affects dynamic visual acuity in healthy young participants. [Subjects and Methods] This study was a double-blinded, prospective, randomized, controlled trial. Thirty healthy young subjects (ages 21 to 30 years) participated in the study. Participants were randomly divided into an experimental group (n=15) and a control group (n=15). The experimental group performed an exercise designed to induce neck muscle fatigue ...

  11. Prediction of Muscle Fatigue during Minimally Invasive Surgery Using Recurrence Quantification Analysis

    Ali Keshavarz Panahi; Sohyung Cho

    2016-01-01

    Due to its inherent complexity such as limited work volume and degree of freedom, minimally invasive surgery (MIS) is ergonomically challenging to surgeons compared to traditional open surgery. Specifically, MIS can expose performing surgeons to excessive ergonomic risks including muscle fatigue that may lead to critical errors in surgical procedures. Therefore, detecting the vulnerable muscles and time-to-fatigue during MIS is of great importance in order to prevent these errors. The main go...

  12. A new approach to muscle fatigue evaluation for Push/Pull task

    Ma, Ruina; Chablat, Damien; Bennis, Fouad

    2012-01-01

    Pushing/Pulling tasks is an important part of work in many industries. Usually, most researchers study the Push/Pull tasks by analyzing different posture conditions, force requirements, velocity factors, etc. However few studies have reported the effects of fatigue. Fatigue caused by physical loading is one of the main reasons responsible for MusculoSkeletal Disorders (MSD). In this paper, muscle groups of articulation is considered and from joint level a new approach is proposed for muscle f...

  13. Cancer cachexia decreases specific force and accelerates fatigue in limb muscle

    Roberts, B.M. [1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610 (United States); Frye, G.S.; Ahn, B.; Ferreira, L.F. [1864 Stadium Road, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32610 (United States); Judge, A.R., E-mail: arjudge@phhp.ufl.edu [1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610 (United States)

    2013-06-07

    Highlights: •C-26 cancer cachexia causes a significant decrease in limb muscle absolute force. •C-26 cancer cachexia causes a significant decrease in limb muscle specific force. •C-26 cancer cachexia decreases fatigue resistance in the soleus muscle. •C-26 cancer cachexia prolongs time to peak twitch tension in limb muscle. •C-26 cancer cachexia prolongs one half twitch relaxation time in limb muscle. -- Abstract: Cancer cachexia is a complex metabolic syndrome that is characterized by the loss of skeletal muscle mass and weakness, which compromises physical function, reduces quality of life, and ultimately can lead to mortality. Experimental models of cancer cachexia have recapitulated this skeletal muscle atrophy and consequent decline in muscle force generating capacity. However, more recently, we provided evidence that during severe cancer cachexia muscle weakness in the diaphragm muscle cannot be entirely accounted for by the muscle atrophy. This indicates that muscle weakness is not just a consequence of muscle atrophy but that there is also significant contractile dysfunction. The current study aimed to determine whether contractile dysfunction is also present in limb muscles during severe Colon-26 (C26) carcinoma cachexia by studying the glycolytic extensor digitorum longus (EDL) muscle and the oxidative soleus muscle, which has an activity pattern that more closely resembles the diaphragm. Severe C-26 cancer cachexia caused significant muscle fiber atrophy and a reduction in maximum absolute force in both the EDL and soleus muscles. However, normalization to muscle cross sectional area further demonstrated a 13% decrease in maximum isometric specific force in the EDL and an even greater decrease (17%) in maximum isometric specific force in the soleus. Time to peak tension and half relaxation time were also significantly slowed in both the EDL and the solei from C-26 mice compared to controls. Since, in addition to postural control, the oxidative

  14. Cancer cachexia decreases specific force and accelerates fatigue in limb muscle

    Highlights: •C-26 cancer cachexia causes a significant decrease in limb muscle absolute force. •C-26 cancer cachexia causes a significant decrease in limb muscle specific force. •C-26 cancer cachexia decreases fatigue resistance in the soleus muscle. •C-26 cancer cachexia prolongs time to peak twitch tension in limb muscle. •C-26 cancer cachexia prolongs one half twitch relaxation time in limb muscle. -- Abstract: Cancer cachexia is a complex metabolic syndrome that is characterized by the loss of skeletal muscle mass and weakness, which compromises physical function, reduces quality of life, and ultimately can lead to mortality. Experimental models of cancer cachexia have recapitulated this skeletal muscle atrophy and consequent decline in muscle force generating capacity. However, more recently, we provided evidence that during severe cancer cachexia muscle weakness in the diaphragm muscle cannot be entirely accounted for by the muscle atrophy. This indicates that muscle weakness is not just a consequence of muscle atrophy but that there is also significant contractile dysfunction. The current study aimed to determine whether contractile dysfunction is also present in limb muscles during severe Colon-26 (C26) carcinoma cachexia by studying the glycolytic extensor digitorum longus (EDL) muscle and the oxidative soleus muscle, which has an activity pattern that more closely resembles the diaphragm. Severe C-26 cancer cachexia caused significant muscle fiber atrophy and a reduction in maximum absolute force in both the EDL and soleus muscles. However, normalization to muscle cross sectional area further demonstrated a 13% decrease in maximum isometric specific force in the EDL and an even greater decrease (17%) in maximum isometric specific force in the soleus. Time to peak tension and half relaxation time were also significantly slowed in both the EDL and the solei from C-26 mice compared to controls. Since, in addition to postural control, the oxidative

  15. Intercostal and forearm muscle deoxygenation during respiratory fatigue in patients with heart failure: potential role of a respiratory muscle metaboreflex

    A.M. Moreno

    2014-11-01

    Full Text Available The purpose of this study was to determine the effect of respiratory muscle fatigue on intercostal and forearm muscle perfusion and oxygenation in patients with heart failure. Five clinically stable heart failure patients with respiratory muscle weakness (age, 66±12 years; left ventricle ejection fraction, 34±3% and nine matched healthy controls underwent a respiratory muscle fatigue protocol, breathing against a fixed resistance at 60% of their maximal inspiratory pressure for as long as they could sustain the predetermined inspiratory pressure. Intercostal and forearm muscle blood volume and oxygenation were continuously monitored by near-infrared spectroscopy with transducers placed on the seventh left intercostal space and the left forearm. Data were compared by two-way ANOVA and Bonferroni correction. Respiratory fatigue occurred at 5.1±1.3 min in heart failure patients and at 9.3±1.4 min in controls (P0.05. Respiratory fatigue in heart failure reduced intercostal and forearm muscle blood volume (P<0.05 along with decreased tissue oxygenation both in intercostal (heart failure, -2.6±1.6%; controls, +1.6±0.5%; P<0.05 and in forearm muscles (heart failure, -4.5±0.5%; controls, +0.5±0.8%; P<0.05. These results suggest that respiratory fatigue in patients with heart failure causes an oxygen demand/delivery mismatch in respiratory muscles, probably leading to a reflex reduction in peripheral limb muscle perfusion, featuring a respiratory metaboreflex.

  16. Postural strategy changes with fatigue of the lumbar extensor muscles.

    Wilson, Erin L; Madigan, Michael L; Davidson, Bradley S; Nussbaum, Maury A

    2006-04-01

    The purpose of this study was to investigate the effect of lumbar extensor fatigue on postural strategy in response to a balance perturbation. Anteriorly-directed force perturbations were applied to the upper back with a padded pendulum and attempted to challenge the postural control system without eliciting a stepping response. In three separate sessions, subjects were perturbed both before and after a fatiguing protocol that induced lumbar extensor fatigue to one of three different fatigue levels. Postural strategy was quantified using center of pressure position along with joint angles and joint torques for the ankle, knee, hip, and "low back" joints. Results showed both proactive and reactive changes in postural strategy. Proactive changes involved a slight anterior lean prior to the perturbation, and reactive changes were consistent with a shift toward more of a hip strategy with fatigue. In addition, results suggested that subjects classified as moving mostly at the hip prior to fatigue were more affected by fatigue compared to subjects classified as moving roughly equal amounts at the ankle and hip prior to fatigue. Increasing fatigue level exaggerated some, but not all, of the changes in postural strategy with fatigue. These findings illustrate that neuromuscular fatigue can influence postural strategy in response to a balance perturbation. PMID:16023345

  17. Control of abdominal and expiratory intercostal muscle activity during vomiting - Role of ventral respiratory group expiratory neurons

    Miller, Alan D.; Tan, L. K.; Suzuki, Ichiro

    1987-01-01

    The role of ventral respiratory group (VRG) expiratory (E) neurons in the control of abdominal and internal intercostal muscle activity during vomiting was investigated in cats. Two series of experiments were performed: in one, the activity of VRG E neurons was recorded during fictive vomiting in cats that were decerebrated, paralyzed, and artificially ventilated; in the second, the abdominal muscle activity during vomiting was compared before and after sectioning the axons of descending VRG E neurons in decerebrate spontaneously breathing cats. The results show that about two-thirds of VRG E neurons that project at least as far caudally as the lower thoracic cord contribute to internal intercostal muscle activity during vomiting. The remaining VRG E neurons contribute to abdominal muscle activation. As shown by severing the axons of the VRG E neurons, other, as yet unidenified, inputs (either descending from the brain stem or arising from spinal reflexes) can also produce abdominal muscle activation.

  18. The Development of Muscle Fatigue Suppresses Auditory Sensory Gating (P50) during Sustained Contraction

    Aleksandrov, Aleksander A.; Dmitrieva, Elena S.; Stankevich, Ludmila N.; Knyazeva, Veronika M.; Shestakova, Anna N.

    2016-01-01

    Our aim was to study the influence of fatigue development on sensory gating during a muscle load. The fatiguing task was sustained contraction of a handgrip dynamometer with 7 and 30% maximum voluntary contraction (MVC). The suppression of P50, an auditory event-related potential, was used as the sensory gating index in the paired-click paradigm with a 500 ms interstimulus interval; the difference between the P50 amplitudes of the first and the second stimuli of the pair was used as the sensory gating index. We found that the 30% MVC fatigue development strongly decreased sensory gating, sometimes totally suppressing it. We concluded that central fatigue impaired motor performance and strongly suppressed inhibitory processes, as shown by the decreased P50 amplitude to the second stimulus. Therefore, muscle central fatigue influences sensory gating, similar to schizophrenia spectrum disorders. PMID:27458348

  19. Mobility-Related Fatigue, Walking Speed, and Muscle Strength in Older People

    Mänty, Minna; Mendes de Leon, Carlos F.; Rantanen, Taina;

    2012-01-01

    among men (b = −.04, p < .001) but not among women (b = −.005, p = .64). Among men, muscle strength accounted up to 15% for the association between baseline fatigue and change in maximum walking speed. Conclusions. Mobility-related fatigue is associated with slower walking speed in older adults. The......Background. Fatigue is an important early marker of functional decline among older people, but the mechanisms underlying this association are not fully understood. The purpose of the present study was to examine the association between mobility-related fatigue and walking speed and to test the...... degree to which muscle strength accounts for this association. Methods. The study is based on baseline (n = 523) and 5-year follow-up data (n = 292) from a cohort of 75-year-old persons. Standardized assessments include self-report measures of mobility-related fatigue (score range 0–6) and medical...

  20. Changes in presumed motor cortical activity during fatiguing muscle contraction in humans

    Seifert, Thomas; Petersen, Nicolas Caesar

    2010-01-01

    the course of fatiguing muscle activity, which demonstrates activity changes in cortical or spinal networks during fatiguing exercise. Here, we investigate cortical mechanisms that are actively involved in driving the contracting muscles. METHODS: During a sustained submaximal contraction (30% of...... electromyographic (EMG) activity. The magnitude of the suppression was evaluated relative to the mean EMG activity during the 50 ms prior to the cortical stimulus. RESULTS: During the first 2 min of the fatiguing muscle contraction the suppression was 10 +/- 0.9% of the ongoing EMG activity. At 2 min prior to task...... failure the suppression had reached 16 +/- 2.1%. In control experiments without fatigue we did not find a similar increase in suppression with increasing levels of ongoing EMG activity. CONCLUSION: Using a form of TMS which reduces cortical output to motor neurones (and disfacilitates them), this study...

  1. Reliability of Abdominal Muscle Stiffness Measured Using Elastography during Trunk Rehabilitation Exercises.

    MacDonald, David; Wan, Alan; McPhee, Megan; Tucker, Kylie; Hug, François

    2016-04-01

    The aim of this study was to assess the intra-session and inter-rater reliability of shear modulus measured in abdominal muscles during two commonly used trunk stability exercises. Thirty healthy volunteers performed a series of abdominal hollow and abdominal brace tasks. Supersonic shear imaging was used to measure the shear modulus (considered an index of muscle tension) of the four anterior trunk muscles: obliquus externus abdominis, obliquus internus abdominis, transversus abdominis and rectus abdominis. Because of measurement artifacts, internus abdominis and transversus abdominis data were not analyzed for 36.7% and 26.7% of the participants, respectively. These participants exhibited thicker superficial fat layers than the others. For the remaining participants, fair to excellent intra-session and inter-rater reliability was observed with moderate to high intra-class coefficients (0.45-0.97) and low to moderate standard error of measurement values (0.38-3.53 kPa). Reliability values were consistently greater for superficial than for deeper muscles. PMID:26746381

  2. Muscle fatigue and exhaustion during dynamic leg exercise in normoxia and hypobaric hypoxia

    Fulco, C S; Lewis, S F; Frykman, Peter;

    1996-01-01

    Using an exercise device that integrates maximal voluntary static contraction (MVC) of knee extensor muscles with dynamic knee extension, we compared progressive muscle fatigue, i.e., rate of decline in force-generating capacity, in normoxia (758 Torr) and hypobaric hypoxia (464 Torr). Eight...... closely to impaired shortening velocity than to failure of force-generating capacity....

  3. Anxiety's Effect on Muscle Activation and Fatigue in Trumpet Players: A Pilot Study.

    Rumsey, Hannah E; Aggarwal, Sahil; Hobson, Erin M; Park, Jeeyn; Pidcoe, Peter

    2015-12-01

    Due to the high percentage of musicians who suffer from musculoskeletal disorders, there is a need for more research in the field of music and medicine. The purpose of this study was to analyze the possible relationship between anxiety, muscle activation, and muscle fatigue in undergraduate trumpet players. Assessment tools included surface electromyography (sEMG) data, State Trait Anxiety Inventory (STAI), and Visual Analogue Scales (VAS) of perceived anxiety. Data were collected from 27 undergraduate music students across five universities (22 males, 5 females) aged 18 to 24 years. The three muscles targeted by the sEMG were the upper trapezius, sternocleidomastoid, and masseter muscles. Participants were randomly divided into two single-blinded groups: (1) anxiety-induction and (2) control. The anxiety-induction group was instructed to play as accurately as possible and informed that mistakes were being counted and evaluated, while the control group was instructed to play without any concern for possible mistakes. The anxiety-induction group was shown to have more masseter muscle activation than the control; the anxiety-induction group also displayed a higher fatigue rate in all three muscles versus the controls. Subjects with high perceived-anxiety (as measured by VAS) displayed higher masseter activation and higher fatigue rates in the upper trapezius and sternocleidomastoid than non-anxious participants. Despite these notable trends, there was no statistical significance for any of the muscle groups for muscle activation or fatigue. PMID:26614974

  4. Extrapulmonary features of bronchiectasis: muscle function, exercise capacity, fatigue, and health status

    Ozalp Ozge

    2012-06-01

    Full Text Available Abstract Background There are limited number of studies investigating extrapulmonary manifestations of bronchiectasis. The purpose of this study was to compare peripheral muscle function, exercise capacity, fatigue, and health status between patients with bronchiectasis and healthy subjects in order to provide documented differences in these characteristics for individuals with and without bronchiectasis. Methods Twenty patients with bronchiectasis (43.5 ± 14.1 years and 20 healthy subjects (43.0 ± 10.9 years participated in the study. Pulmonary function, respiratory muscle strength (maximal expiratory pressure – MIP - and maximal expiratory pressure - MEP, and dyspnea perception using the Modified Medical Research Council Dyspnea Scale (MMRC were determined. A six-minute walk test (6MWT was performed. Quadriceps muscle, shoulder abductor, and hand grip strength (QMS, SAS, and HGS, respectively using a hand held dynamometer and peripheral muscle endurance by a squat test were measured. Fatigue perception and health status were determined using the Fatigue Severity Scale (FSS and the Leicester Cough Questionnaire (LCQ, respectively. Results Number of squats, 6MWT distance, and LCQ scores as well as lung function testing values and respiratory muscle strength were significantly lower and MMRC and FSS scores were significantly higher in patients with bronchiectasis than those of healthy subjects (p p p p p  Conclusions Peripheral muscle endurance, exercise capacity, fatigue and health status were adversely affected by the presence of bronchiectasis. Fatigue was associated with dyspnea and health status. Respiratory muscle strength was related to peripheral muscle strength and health status, but not to fatigue, peripheral muscle endurance or exercise capacity. These findings may provide insight for outcome measures for pulmonary rehabilitation programs for patients with bronchiectasis.

  5. Detection of skeletal muscle fatigue in patients with heart failure using electromyography.

    Wilson, J R; Mancini, D M; Simson, M

    1992-08-15

    Patients with heart failure frequently report that leg fatigue limits maximal exercise capacity. However, objective documentation of muscle fatigue has not been obtained in such patients. In normal subjects, muscle fatigue during constant work load exercise is associated with an increase in electrical activity generated per contraction due to use of additional muscle fibers to compensate for fiber fatigue. The present study was performed to determine if this approach can be used to document muscle fatigue in patients with heart failure. Vastus lateralis surface electromyograms were monitored in 8 ambulatory patients with nonedematous heart failure and 6 normal subjects during maximal bicycle exercise (20 W increments every 2 minutes). The electromyogram was stored on tape and subsequently analyzed for integrated root-mean-square voltage/contraction (iRMSV). At each work load, the iRMSV of the first and last 30 seconds of the work load were compared. The maximal work load achieved by patients with heart failure was significantly lower (73 +/- 22 W) than that by normal subjects (150 +/- 15 W; p less than 0.01). Both groups had no significant difference between the initial and final iRMSV at submaximal work loads. However, during the 2 highest work loads, both groups reported leg fatigue and had significant increases in iRMSV, consistent with muscle fiber fatigue (maximal work load: 259 +/- 59 to 279 +/- 58 mv.ms [normals] vs 258 +/- 94 to 283 +/- 93 mv.ms [heart failure]; p less than 0.03). The data indicate that the surface electromyogram can be used to detect skeletal muscle fatigue in patients with heart failure.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1642187

  6. Effects of Localized Muscle Fatigue on Postural Control: Interactive Effects with Inclined Surfaces and Unexpected Loads, and Intervention Efficacy

    Lin, Dingding

    2010-01-01

    Falls in the workplace are a major cause of injuries and fatalities. Muscle fatigue is one important factor that has been linked to a decrement in postural control and a potential increased falling risk. However, potential interactive effects of muscle fatigue with other risk factors remain unclear, and practical interventions are needed to mitigate the adverse effects of muscle fatigue. The current work was conducted to address these research needs through three experimental studies. ...

  7. Multiple causes of fatigue during shortening contractions in rat slow twitch skeletal muscle.

    Kristin Halvorsen Hortemo

    Full Text Available Fatigue in muscles that shorten might have other causes than fatigue during isometric contractions, since both cross-bridge cycling and energy demand are different in the two exercise modes. While isometric contractions are extensively studied, the causes of fatigue in shortening contractions are poorly mapped. Here, we investigate fatigue mechanisms during shortening contractions in slow twitch skeletal muscle in near physiological conditions. Fatigue was induced in rat soleus muscles with maintained blood supply by in situ shortening contractions at 37°C. Muscles were stimulated repeatedly (1 s on/off at 30 Hz for 15 min against a constant load, allowing the muscle to shorten and perform work. Fatigue and subsequent recovery was examined at 20 s, 100 s and 15 min exercise. The effects of prior exercise were investigated in a second exercise bout. Fatigue developed in three distinct phases. During the first 20 s the regulatory protein Myosin Light Chain-2 (slow isoform, MLC-2s was rapidly dephosphorylated in parallel with reduced rate of force development and reduced shortening. In the second phase there was degradation of high-energy phosphates and accumulation of lactate, and these changes were related to slowing of muscle relengthening and relaxation, culminating at 100 s exercise. Slowing of relaxation was also associated with increased leak of calcium from the SR. During the third phase of exercise there was restoration of high-energy phosphates and elimination of lactate, and the slowing of relaxation disappeared, whereas dephosphorylation of MLC-2s and reduced shortening prevailed. Prior exercise improved relaxation parameters in a subsequent exercise bout, and we propose that this effect is a result of less accumulation of lactate due to more rapid onset of oxidative metabolism. The correlation between dephosphorylation of MLC-2s and reduced shortening was confirmed in various experimental settings, and we suggest MLC-2s as an

  8. The muscles of the infrapubic abdominal wall of a 6-month-old Crocodylus niloticus (Reptilia: Crocodylia).

    Fechner, R; Schwarz-Wings, D

    2013-06-01

    The muscles of the infrapubic abdominal wall of crocodilians play an important role in their ventilatory mechanism. Yet the anatomy and homology of these muscles is poorly understood. To gain new insights into the anatomy of the crocodilian infrapubic abdominal wall, we dissected a specimen of Crocodylus niloticus. Origin and insertion of the muscles, as well as their arrangement relative to each other was examined in great detail. The findings were compared with those of other crocodilian taxa to detect potential variability of the muscles of interest. The homology of the muscles was studied by comparing the muscles of the crocodilian infrapubic abdominal wall with those of other diapsids. In Crocodylus niloticus, the infrapubic abdominal wall consists of four muscles: Musculus truncocaudalis, M. ischiotruncus, and Mm. rectus abdominis externus and internus. The arrangement of the muscles of the infrapubic abdominal wall of Crocodylus niloticus is consistent with that found in most other crocodilian taxa. In some crocodilian taxa, an additional muscle, M. ischiopubis, is found. In the remaining diapsids, only M. rectus abdominis is present. The crocodilian M. truncocaudalis, M. ischiotruncus and, if present, M. ischiopubis appear to be derivates of M. rectus abdominis; the development of those might be related to the evolution of the unique crocodilian ventilatory mechanism. PMID:22909340

  9. Computation and Evaluation of Features of Surface Electromyogram to Identify the Force of Muscle Contraction and Muscle Fatigue

    Arjunan, Sridhar P.; Dinesh K. Kumar; Ganesh Naik

    2014-01-01

    The relationship between force of muscle contraction and muscle fatigue with six different features of surface electromyogram (sEMG) was determined by conducting experiments on thirty-five volunteers. The participants performed isometric contractions at 50%, 75%, and 100% of their maximum voluntary contraction (MVC). Six features were considered in this study: normalised spectral index (NSM5), median frequency, root mean square, waveform length, normalised root mean square (NRMS), and increas...

  10. The 400- and 800-m Track Running Induces Inspiratory Muscle Fatigue in Trained Female Middle-Distance Runners.

    Ohya, Toshiyuki; Yamanaka, Ryo; Hagiwara, Masahiro; Oriishi, Marie; Suzuki, Yasuhiro

    2016-05-01

    Ohya, T, Yamanaka, R, Hagiwara, M, Oriishi, M, and Suzuki, Y. The 400- and 800-m track running induces inspiratory muscle fatigue in trained female middle-distance runners. J Strength Cond Res 30(5): 1433-1437, 2016-Inspiratory muscle fatigue (IMF) may limit exercise performance. A few studies have reported that IMF occurs after short-duration swimming exercise, but whether short-duration running can induce IMF remains unclear. Intra-abdominal pressure is increased during running through diaphragmatic activation to stabilize the spine during movements of the upper limbs. This occurs along with the increased inspiratory muscle effort associated with increased respirations during exercise; thus, we hypothesized that short-duration running exercise would induce IMF. To test this hypothesis, we measured maximal inspiratory pressure (MIP) before and after 400- and 800-m track running sessions. Eight female middle-distance (400, 800 m) runners performed a 400- and 800-m running test. Maximal inspiratory pressure was measured before and after each test using a portable autospirometer. The mean MIPs were significantly lower after running than before running; values obtained were 107 ± 25 vs. 97 ± 27 cmH2O (p = 0.01, effect size [ES] = 0.65) and 108 ± 26 vs. 92 ± 27 cmH2O (p = 0.01, ES = 0.74) before vs. after the 400- and 800-m tests, respectively. The mean MIP after the 800-m test was significantly lower than after the 400-m test (p = 0.04, ES = 0.48). There was no correlation between IMF value and running time (r = 0.53 and r = -0.28 for either the 400- and 800-m tests, respectively; p > 0.05). In conclusion, IMF occurs after short-duration running exercise. Coaches could consider prescribing inspiratory muscle training or warm-up in an effort to reduce the inevitable IMF associated with maximal effort running. PMID:26422611

  11. A Real-Time Fatigue Monitoring and Analysis System for Lower Extremity Muscles with Cycling Movement

    Szi-Wen Chen

    2014-07-01

    Full Text Available A real-time muscle fatigue monitoring system was developed to quantitatively detect the muscle fatigue of subjects during cycling movement, where a fatigue progression measure (FPM was built-in. During the cycling movement, the electromyogram (EMG signals of the vastus lateralis and gastrocnemius muscles in one leg as well as cycling speed are synchronously measured in a real-time fashion. In addition, the heart rate (HR and the Borg rating of perceived exertion scale value are recorded per minute. Using the EMG signals, the electrical activity and median frequency (MF are calculated per cycle. Moreover, the updated FPM, based on the percentage of reduced MF counts during cycling movement, is calculated to measure the onset time and the progressive process of muscle fatigue. To demonstrate the performance of our system, five young healthy subjects were recruited. Each subject was asked to maintain a fixed speed of 60 RPM, as best he/she could, under a constant load during the pedaling. When the speed reached 20 RPM or the HR reached the maximal training HR, the experiment was then terminated immediately. The experimental results show that the proposed system may provide an on-line fatigue monitoring and analysis for the lower extremity muscles during cycling movement.

  12. Reliability of ultrasound measurement of automatic activity of the abdominal muscle in participants with and without chronic low back pain

    Arab, Amir Massoud; Rasouli, Omid; Amiri, Mohsen; Tahan, Nahid

    2013-01-01

    Background Ultrasound (US) imaging has been considered as a non-invasive technique to measure thickness and estimate relative abdominal muscle activity. Although some studies have assessed the reliability of US imaging, no study has assessed the reliability of US measurement of automatic activity of abdominal muscles in positions with different levels of stability in participants with chronic low back pain (cLBP). The purpose of this study was to investigate within-day and between-days reliab...

  13. The Effect of Trunk Stabilization Exercise Using an Unstable Surface on the Abdominal Muscle Structure and Balance of Stroke Patients

    Yoo, Junsang; Jeong, Juri; Lee, Wanhee

    2014-01-01

    [Purpose] This study investigated the effect of unstable surface trunk stabilization exercise on the abdominal muscle structure and balance of stroke patients. [Subjects] The subjects were divided into two groups: an unstable surface trunk stabilization exercise group (n=13), and a stable surface trunk stabilization exercise group (n=11). [Methods] Both groups performed trunk stabilization exercise for 30 minutes, 3 days per week for 6 weeks. Abdominal muscle thickness and the Berg Balance Sc...

  14. Reliability of ultrasound imaging for the measurement of abdominal muscle thickness in typically developing children

    M. Unger

    2010-02-01

    Full Text Available Introduction: A bdominal muscles are key to both posture andgait in both children with typical development (TD and with disabilities.Ultrasound (US imaging is a potential non-invasive method for investigatingactivity in these muscles. This study therefore aimed to determine the inter-tester and intra-tester reliability of B-mode US for investigating transverseabdominus (TrA , rectus abdominus (RA and external- (EO and internaloblique (IO muscle activity in children with TD. Design: A  prospective cor-relational descriptive study.  Participants:  Eighty six, 6-13year old children from one private and one public mainstream school. Outcome measures: Two sets of B-mode US images where captured per subject during rest and during head-up, resisted head-up and resisted sling activities. Intra-class Correlation Coefficients (ICC and standard error of measurement (SEM were used to analyse the data. Results: Good correlation was found for both test - retest condi-tions for all four muscles tested during rest: 0.91(TrA ; 0.90(IO; 0.91(EO; 0.94(RA for intra-tester reliability and0.74(TrA ; 0.88(IO; 0.74(EO; 0.83(RA for inter-tester reliability. Repeatability of thickness measures during activity however showed variation in recruitment patterns. A  significant correlation was found between age and BMI andresting abdominal muscle thickness (p<0.001. Conclusion: The study supports the reliability of US measurement of resting abdominal muscles and of the RA  under active conditions in children aged six to 13. However the stability o measurement of the other muscles under active conditions still needs to be established.

  15. Active behavior of abdominal wall muscles: Experimental results and numerical model formulation.

    Grasa, J; Sierra, M; Lauzeral, N; Muñoz, M J; Miana-Mena, F J; Calvo, B

    2016-08-01

    In the present study a computational finite element technique is proposed to simulate the mechanical response of muscles in the abdominal wall. This technique considers the active behavior of the tissue taking into account both collagen and muscle fiber directions. In an attempt to obtain the computational response as close as possible to real muscles, the parameters needed to adjust the mathematical formulation were determined from in vitro experimental tests. Experiments were conducted on male New Zealand White rabbits (2047±34g) and the active properties of three different muscles: Rectus Abdominis, External Oblique and multi-layered samples formed by three muscles (External Oblique, Internal Oblique, and Transversus Abdominis) were characterized. The parameters obtained for each muscle were incorporated into a finite strain formulation to simulate active behavior of muscles incorporating the anisotropy of the tissue. The results show the potential of the model to predict the anisotropic behavior of the tissue associated to fibers and how this influences on the strain, stress and generated force during an isometric contraction. PMID:27111629

  16. Effects of lower extremity muscle fatigue on the outcomes of slip-induced falls

    Parijat, Prakriti; Lockhart, Thurmon E.

    2008-01-01

    Slip-induced fall accidents continue to be a significant cause of fatal injuries and economic losses. Identifying the risk factors causing slip-induced falls is key to developing better preventive measures to reduce fall accidents. Although epidemiological studies suggest localised muscle fatigue may be one of the risk factors for slip-induced falls, there has been no documented biomechanical study examining the relationship between fatigue and fall accidents. As such, the overall objective o...

  17. Changes in the flexion relaxation response induced by lumbar muscle fatigue

    Cantin Vincent; Centomo Hugo; Jeffrey-Gauthier Renaud; Lafond Danik; Descarreaux Martin

    2008-01-01

    Abstract Background The flexion relaxation phenomenon (FRP) is an interesting model to study the modulation of lumbar stability. Previous investigations have explored the effect of load, angular velocity and posture on this particular response. However, the influence of muscular fatigue on FRP parameters has not been thoroughly examined. The objective of the study is to identify the effect of erector spinae (ES) muscle fatigue and spine loading on myoelectric silence onset and cessation in he...

  18. A novel approach for determining fatigue resistances of different muscle groups in static cases

    Ma, Liang; Bennis, Fouad; Zhang, Wei; Hu, Bo; Guillaume, François; 10.1016/j.ergon.2010.11.005

    2011-01-01

    In ergonomics and biomechanics, muscle fatigue models based on maximum endurance time (MET) models are often used to integrate fatigue effect into ergonomic and biomechanical application. However, due to the empirical principle of those MET models, the disadvantages of this method are: 1) the MET models cannot reveal the muscle physiology background very well; 2) there is no general formation for those MET models to predict MET. In this paper, a theoretical MET model is extended from a simple muscle fatigue model with consideration of the external load and maximum voluntary contraction in passive static exertion cases. The universal availability of the extended MET model is analyzed in comparison to 24 existing empirical MET models. Using mathematical regression method, 21 of the 24 MET models have intraclass correlations over 0.9, which means the extended MET model could replace the existing MET models in a general and computationally efficient way. In addition, an important parameter, fatigability (or fatig...

  19. A new muscle fatigue and recovery model and its ergonomics application in human simulation

    Ma, Liang; Bennis, Fouad; Zhang, Wei; Guillaume, François; 10.1080/17452759.2010.504056

    2010-01-01

    Although automatic techniques have been employed in manufacturing industries to increase productivity and efficiency, there are still lots of manual handling jobs, especially for assembly and maintenance jobs. In these jobs, musculoskeletal disorders (MSDs) are one of the major health problems due to overload and cumulative physical fatigue. With combination of conventional posture analysis techniques, digital human modelling and simulation (DHM) techniques have been developed and commercialized to evaluate the potential physical exposures. However, those ergonomics analysis tools are mainly based on posture analysis techniques, and until now there is still no fatigue index available in the commercial software to evaluate the physical fatigue easily and quickly. In this paper, a new muscle fatigue and recovery model is proposed and extended to evaluate joint fatigue level in manual handling jobs. A special application case is described and analyzed by digital human simulation technique.

  20. Trunk muscle fatigue during a lateral isometric hold test: what are we evaluating?

    Pagé Isabelle

    2012-04-01

    Full Text Available Abstract Background Side bridge endurance protocols have been suggested to evaluate lateral trunk flexor and/or spine stabilizer muscles. To date, no study has investigated muscle recruitment and fatigability during these protocols. Therefore the purpose of our study was to quantify fatigue parameters in various trunk muscles during a modified side bridge endurance task (i.e. a lateral isometric hold test on a 45° roman chair apparatus and determine which primary trunk muscles get fatigued during this task. It was hypothesized that the ipsilateral external oblique and lumbar erector spinae muscles will exhibit the highest fatigue indices. Methods Twenty-two healthy subjects participated in this study. The experimental session included left and right lateral isometric hold tasks preceded and followed by 3 maximal voluntary contractions in the same position. Surface electromyography (EMG recordings were obtained bilaterally from the external oblique, rectus abdominis, and L2 and L5 erector spinae. Statistical analysis were conducted to compare the right and left maximal voluntary contractions (MVC, surface EMG activities, right vs. left holding times and decay rate of the median frequency as the percent change from the initial value (NMFslope. Results No significant left and right lateral isometric hold tests differences were observed neither for holding times (97.2 ± 21.5 sec and 96.7 ± 24.9 sec respectively nor for pre and post fatigue root mean square during MVCs. However, participants showed significant decreases of MVCs between pre and post fatigue measurements for both the left and right lateral isometric hold tests. Statistical analysis showed that a significantly NMFslope of the ipsilateral external oblique during both conditions, and a NMFslope of the contralateral L5 erector spinae during the left lateral isometric hold test were steeper than those of the other side’s respective muscles. Although some participants

  1. Evoked EMG-based torque prediction under muscle fatigue in implanted neural stimulation

    Hayashibe, Mitsuhiro; Zhang, Qin; Guiraud, David; Fattal, Charles

    2011-10-01

    In patients with complete spinal cord injury, fatigue occurs rapidly and there is no proprioceptive feedback regarding the current muscle condition. Therefore, it is essential to monitor the muscle state and assess the expected muscle response to improve the current FES system toward adaptive force/torque control in the presence of muscle fatigue. Our team implanted neural and epimysial electrodes in a complete paraplegic patient in 1999. We carried out a case study, in the specific case of implanted stimulation, in order to verify the corresponding torque prediction based on stimulus evoked EMG (eEMG) when muscle fatigue is occurring during electrical stimulation. Indeed, in implanted stimulation, the relationship between stimulation parameters and output torques is more stable than external stimulation in which the electrode location strongly affects the quality of the recruitment. Thus, the assumption that changes in the stimulation-torque relationship would be mainly due to muscle fatigue can be made reasonably. The eEMG was proved to be correlated to the generated torque during the continuous stimulation while the frequency of eEMG also decreased during fatigue. The median frequency showed a similar variation trend to the mean absolute value of eEMG. Torque prediction during fatigue-inducing tests was performed based on eEMG in model cross-validation where the model was identified using recruitment test data. The torque prediction, apart from the potentiation period, showed acceptable tracking performances that would enable us to perform adaptive closed-loop control through implanted neural stimulation in the future.

  2. Effect of temperature on crossbridge force changes during fatigue and recovery in intact mouse muscle fibers.

    Marta Nocella

    Full Text Available Repetitive or prolonged muscle contractions induce muscular fatigue, defined as the inability of the muscle to maintain the initial tension or power output. In the present experiments, made on intact fiber bundles from FDB mouse, fatigue and recovery from fatigue were investigated at 24°C and 35°C. Force and stiffness were measured during tetani elicited every 90 s during the pre-fatigue control phase and recovery and every 1.5 s during the fatiguing phase made of 105 consecutive tetani. The results showed that force decline could be split in an initial phase followed by a later one. Loss of force during the first phase was smaller and slower at 35°C than at 24°C, whereas force decline during the later phase was greater at 35°C so that total force depression at the end of fatigue was the same at both temperatures. The initial force decline occurred without great reduction of fiber stiffness and was attributed to a decrease of the average force per attached crossbridge. Force decline during the later phase was accompanied by a proportional stiffness decrease and was attributed to a decrease of the number of attached crossbridge. Similarly to fatigue, at both 24 and 35°C, force recovery occurred in two phases: the first associated with the recovery of the average force per attached crossbridge and the second due to the recovery of the pre-fatigue attached crossbridge number. These changes, symmetrical to those occurring during fatigue, are consistent with the idea that, i initial phase is due to the direct fast inhibitory effect of [Pi]i increase during fatigue on crossbridge force; ii the second phase is due to the delayed reduction of Ca(2+ release and /or reduction of the Ca(2+ sensitivity of the myofibrils due to high [Pi]i.

  3. Detection and Alert of muscle fatigue considering a Surface Electromyography Chaotic Model

    Herrera, V; Romero, J F [Engineering, Modeling and Applied Social Sciences Center, ABC Federal University, Santo Andr - SP (Brazil); Amestegui, M, E-mail: victoria.herrera@ufabc.edu.br [Engineering Faculty, Electronics Engineering, Universidad Mayor de San Andres, La Paz (Bolivia, Plurinational State of)

    2011-03-01

    This work propose a detection and alert algorithm for muscle fatigue in paraplegic patients undergoing electro-therapy sessions. The procedure is based on a mathematical chaotic model emulating physiological signals and Continuous Wavelet Transform (CWT). The chaotic model developed is based on a logistic map that provides suitable data accomplishing some physiological signal class patterns. The CWT was applied to signals generated by the model and the resulting vector was obtained through Total Wavelet Entropy (TWE). In this sense, the presented work propose a viable and practical alert and detection algorithm for muscle fatigue.

  4. Detection and Alert of muscle fatigue considering a Surface Electromyography Chaotic Model

    This work propose a detection and alert algorithm for muscle fatigue in paraplegic patients undergoing electro-therapy sessions. The procedure is based on a mathematical chaotic model emulating physiological signals and Continuous Wavelet Transform (CWT). The chaotic model developed is based on a logistic map that provides suitable data accomplishing some physiological signal class patterns. The CWT was applied to signals generated by the model and the resulting vector was obtained through Total Wavelet Entropy (TWE). In this sense, the presented work propose a viable and practical alert and detection algorithm for muscle fatigue.

  5. New Dynamic Muscle Fatigue Model to Limit Musculo-Skeletal Disorder

    Seth, Deep; Chablat, Damien; Bennis, Fouad; Sakka, Sophie; Jubeau, Marc; Nordez, Antoine

    2016-01-01

    Muscle fatigue is one of the reason leads to Musculo-Skeletal Disorder(MSD). Automation in today's industries makes human effort very less, but still there are many industries in which human have to do complex and repetitive tasks manually. The society/companies have to pay attention on this issue due to the new laws on penibility or repetitive tasks. The objective of this paper is to experimentally validate a new dynamic muscle fatigue model using electromyog-raphy (EMG) and Maximum voluntar...

  6. Impaired sarcoplasmic reticulum Ca(2+) release rate after fatiguing stimulation in rat skeletal muscle

    Ørtenblad, Niels; Sjøgaard, G; Madsen, Klavs

    2000-01-01

    The purpose of the study was to characterize the sarcoplasmic reticulum (SR) function and contractile properties before and during recovery from fatigue in the rat extensor digitorum longus muscle. Fatiguing contractions (60 Hz, 150 ms/s for 4 min) induced a reduction of the SR Ca(2+) release rate.......05). Despite a slowing of the relaxation rate, we did not find any significant alterations in the SR Ca(2+) uptake function. These data demonstrate that the Ca(2+) release mechanism of SR is sensitive to repetitive in vitro muscle contraction. Moreover, the results indicate that +dF/dt to some extent depends...

  7. Abdominal Muscle Activity during Mechanical Ventilation Increases Lung Injury in Severe Acute Respiratory Distress Syndrome.

    Xianming Zhang

    Full Text Available It has proved that muscle paralysis was more protective for injured lung in severe acute respiratory distress syndrome (ARDS, but the precise mechanism is not clear. The purpose of this study was to test the hypothesis that abdominal muscle activity during mechanically ventilation increases lung injury in severe ARDS.Eighteen male Beagles were studied under mechanical ventilation with anesthesia. Severe ARDS was induced by repetitive oleic acid infusion. After lung injury, Beagles were randomly assigned into spontaneous breathing group (BIPAPSB and abdominal muscle paralysis group (BIPAPAP. All groups were ventilated with BIPAP model for 8h, and the high pressure titrated to reached a tidal volume of 6ml/kg, the low pressure was set at 10 cmH2O, with I:E ratio 1:1, and respiratory rate adjusted to a PaCO2 of 35-60 mmHg. Six Beagles without ventilator support comprised the control group. Respiratory variables, end-expiratory volume (EELV and gas exchange were assessed during mechanical ventilation. The levels of Interleukin (IL-6, IL-8 in lung tissue and plasma were measured by qRT-PCR and ELISA respectively. Lung injury scores were determined at end of the experiment.For the comparable ventilator setting, as compared with BIPAPSB group, the BIPAPAP group presented higher EELV (427±47 vs. 366±38 ml and oxygenation index (293±36 vs. 226±31 mmHg, lower levels of IL-6(216.6±48.0 vs. 297.5±71.2 pg/ml and IL-8(246.8±78.2 vs. 357.5±69.3 pg/ml in plasma, and lower express levels of IL-6 mRNA (15.0±3.8 vs. 21.2±3.7 and IL-8 mRNA (18.9±6.8 vs. 29.5±7.9 in lung tissues. In addition, less lung histopathology injury were revealed in the BIPAPAP group (22.5±2.0 vs. 25.2±2.1.Abdominal muscle activity during mechanically ventilation is one of the injurious factors in severe ARDS, so abdominal muscle paralysis might be an effective strategy to minimize ventilator-induce lung injury.

  8. Attenuated fatigue in slow twitch skeletal muscle during isotonic exercise in rats with chronic heart failure.

    Morten Munkvik

    Full Text Available During isometric contractions, slow twitch soleus muscles (SOL from rats with chronic heart failure (chf are more fatigable than those of sham animals. However, a muscle normally shortens during activity and fatigue development is highly task dependent. Therefore, we examined the development of skeletal muscle fatigue during shortening (isotonic contractions in chf and sham-operated rats. Six weeks following coronary artery ligation, infarcted animals were classified as failing (chf if left ventricle end diastolic pressure was >15 mmHg. During isoflurane anaesthesia, SOL with intact blood supply was stimulated (1s on 1s off at 30 Hz for 15 min and allowed to shorten isotonically against a constant afterload. Muscle temperature was maintained at 37°C. In resting muscle, maximum isometric force (F(max and the concentrations of ATP and CrP were not different in the two groups. During stimulation, F(max and the concentrations declined in parallel sham and chf. Fatigue, which was evident as reduced shortening during stimulation, was also not different in the two groups. The isometric force decline was fitted to a bi-exponential decay equation. Both time constants increased transiently and returned to initial values after approximately 200 s of the fatigue protocol. This resulted in a transient rise in baseline tension between stimulations, although this effect which was less prominent in chf than sham. Myosin light chain 2s phosphorylation declined in both groups after 100 s of isotonic contractions, and remained at this level throughout 15 min of stimulation. In spite of higher energy demand during isotonic than isometric contractions, both shortening capacity and rate of isometric force decline were as well or better preserved in fatigued SOL from chf rats than in sham. This observation is in striking contrast to previous reports which have employed isometric contractions to induce fatigue.

  9. A Wireless sEMG Recording System and Its Application to Muscle Fatigue Detection

    Xuan-Han Wu; Kang-Ming Chang; Shin-Hong Liu

    2012-01-01

    Surface electromyography (sEMG) is an important measurement for monitoring exercise and fitness. Because if its high sampling frequency requirement, wireless transmission of sEMG data is a challenge. In this article a wireless sEMG measurement system with a sampling frequency of 2 KHz is developed based upon a MSP 430 microcontroller and Bluetooth transmission. Standard isotonic and isometric muscle contraction are clearly represented in the receiving user interface. Muscle fatigue detection ...

  10. Muscle fatigue in women with primary biliary cirrhosis: Spectral analysis of surface electromyography

    Maria Rosa Biagini; Alessandro Tozzi; Antonello Grippo; Andrea Galli; Stefano Milani; Aldo Amantini

    2006-01-01

    AIM: To evaluate the myoelectric manifestations of peripheral fatigability in patients with primary biliary cirrhosis in comparison to healthy subjects. METHODS: Sixteen women with primary biliary cirrhosis without comorbidity and 13 healthy women matched for age and body mass index (BMI) completed the self reported questionnaire fatigue impact scale. All subjects underwent surface electromyography assessment of peripheral fatigability. Anterior tibial muscle isometric voluntary contraction was executed for 20 s at 80% of maximal voluntary isometric contraction. During the exercise electromyographic signal series were recorded and root mean square (expression of central drive) as well as mean and median of electromyographic signal frequency spectrum (estimates of muscle fatigability) were computed. Each subject executed the trial two times. EMG parameters were normalized, then linear regression was applied and slopes were calculated. RESULTS: Seven patients were fatigued (median fatigue impact scale score: 38, range: 26-66) and 9 were not fatigued (median fatigue impact scale score: 7, range: 0-17). The maximal voluntary isometric contraction was similar in patients (82, 54-115 N) and controls (87,74-101 N), and in patients with high (81, 54-115 N) and low fatigue impact scale scores (86, 65-106 N). Root mean square as well as mean and median of frequency spectrum slopes were compared with the Mann-Whitney U test, and no significant difference was found between fatigued and non-fatigued patients and controls. CONCLUSION: No instrumental evidence of peripheral fatigability can be found in women with primary biliary cirrhosis but no comorbidity, suggesting that fatigue in such patients may be of central origin.

  11. The effect of muscle fatigue on instep kicking kinetics and kinematics in association football.

    Apriantono, Tommy; Nunome, Hiroyuki; Ikegami, Yasuo; Sano, Shinya

    2006-09-01

    The aim of this study was to examine the effect of leg muscle fatigue on the kinetics and kinematics of the instep football kick. Fatigue was induced by repeated, loaded knee extension (40% body weight) and flexion (50% body weight) motions on a weight-training machine until exhaustion. The kicking motions of seven male players were captured three-dimensionally at 500 Hz before and immediately after the fatigue protocol. The significantly slower ball velocity observed in the fatigue condition was due to both reduced lower leg swing speed and poorer ball contact. The reduced leg swing speed, represented by a slower toe linear velocity immediately before ball impact and slower peak lower leg angular velocity, was most likely due to a significantly reduced resultant joint moment and motion-dependent interactive moment during kicking. These results suggest that the specific muscle fatigue induced in the present study not only diminished the ability to generate force, but also disturbed the effective action of the interactive moment leading to poorer inter-segmental coordination during kicking. Moreover, fatigue obscured the eccentric action of the knee flexors immediately before ball impact. This might increase the susceptibility to injury. PMID:16882629

  12. Unilateral agenesis of the abdominal wall musculature: An early muscle deficiency.

    Gerard-Blanluet, Marion; Port-Lis, Marylin; Baumann, Clarisse; Perrin-Sabourin, Laurence; Ebrad, Patrick; Audry, Georges; Delezoide, Anne-Lise; Verloes, Alain

    2010-11-01

    Prune-belly sequence (PBS) usually results from early urethral obstruction. In rare cases, PBS seems to be due to a faulty primary development of the parietal mesenchyme leading to underdevelopment of the abdominal wall musculature, and disorganization of the smooth muscles in the urinary tract. We report on two patients with segmental, unilateral wall musculature deficiency associated with homolateral agenesis of ribs. One patient also had hemivertebrae and the other one ipsilateral diaphragmatic eventration and aplasia cutis. This combination of anomalies may represent a localized deficiency in the development of somitic mesoderm mesenchyme during early embryogenesis. PMID:20949627

  13. Simultaneous electromyography and 31P nuclear magnetic resonance spectroscopy--with application to muscle fatigue

    Vestergaard-Poulsen, P; Thomsen, C; Sinkjaer, T;

    1992-01-01

    changes in human muscle. The aim of this study was to develop a method by which EMG and NMR spectroscopy measurements could be performed simultaneously. All measurements were performed in a whole body 1.5 Tesla NMR scanner. A calf muscle ergometer, designed for use in a whole body NMR scanner, was used......The electromyogram (EMG) is often used to study human muscle fatigue, but the changes in the electromyographic signals during muscle contraction are not well understood in relation to muscle metabolism. The 31P NMR spectroscopy is a semi-quantitative non-invasive method for studying the metabolic....... The subject had the left foot strapped to the ergometer. The anterior tibial EMG was recorded by bipolar surface electrodes. A surface coil was strapped to the anterior tibial muscle next to the EMG electrodes. Simultaneous measurements of surface EMG and surface coil 31P NMR spectroscopy were...

  14. Muscle fatigue in relation to forearm pain and tenderness among professional computer users

    Thomsen, GF; Johnson, PW; Svendsen, Susanne Wulff

    2007-01-01

    response was not explained by differences in the MVC or body mass index. CONCLUSION: Computer users with forearm pain and moderate to severe palpation tenderness had diminished forearm extensor muscle fatigue response. Additional studies are necessary to determine whether this result reflects an adaptive...... response to exposure without any pathophysiological significance, or represents a part of a causal pathway leading to pain....

  15. Muscle Fatigue during Intermittent Exercise in Individuals with Mental Retardation

    Zafeiridis, Andreas; Giagazoglou, Paraskevi; Dipla, Konstantina; Salonikidis, Konstantinos; Karra, Chrisanthi; Kellis, Eleftherios

    2010-01-01

    This study examined fatigue profile during intermittent exercise in 10 men with mild to moderate mental retardation (MR) and 10 men without mental retardation (C). They performed 4 x 30 s maximal knee extensions and flexions with 1-min rest on an isokinetic dynamometer. Peak torque of flexors (PTFL) and extensors (PTEX), total work (TW), and…

  16. Recent insights into muscle fatigue at the cross-bridge level

    EdwardDebold

    2012-06-01

    Full Text Available Muscle fatigue is a complex multi-factorial process in humans that is dependent on the mode and intensity of the contractile activity. The depression in force and/or velocity associated with fatigue can be the result of a failure at any level, from the initial events in the motor cortex of the brain to the formation of an actomyosin cross-bridge in the muscle cell. Factors distal to the neuromuscular junction appear to be most important for fatigue resulting from intense contractile activity. Given that all the force and motion generated by muscle ultimately derives from the cyclical interaction of actin and myosin, researchers have focused heavily on the impact of the accumulation of intracellular metabolites (e.g. Pi, H+ and ADP on the function these contractile proteins. These efforts demonstrate when elevated to the levels reached during intense contractile activity these metabolites can significantly alter a muscles’ force and motion generating capacity. At saturating Ca++ levels, elevated Pi appears to be the primary cause for the loss in maximal isometric force, while increased [H+] and possibly ADP act to slow unloaded shortening velocity. These studies, performed on isolated muscle preparations, provided strong evidence that these metabolites play a causative role in muscular fatigue, however the precise mechanisms through which these metabolites might affect the individual function of the contractile proteins remains unclear because intact muscle is a highly complex structure with the observed contractile properties representing the collective action of billions of myosin molecules. Fortunately more recent experiments on isolated proteins, including some single molecule measurements, are giving us unprecedented insight into the molecular processes that may be at work during fatigue. For example, using isolated actin and myosin in an in vitro motility assay, researchers have demonstrated decreasing pH from a resting level (~7.0 to a

  17. Low force contractions induce fatigue consistent with muscle mRNA expression in people with spinal cord injury

    Petrie, Michael A.; Suneja, Manish; Faidley, Elizabeth; Shields, Richard K.

    2014-01-01

    Abstract Spinal cord injury (SCI) is associated with muscle atrophy, transformation of muscle fibers to a fast fatigable phenotype, metabolic inflexibility (diabetes), and neurogenic osteoporosis. Electrical stimulation of paralyzed muscle may mitigate muscle metabolic abnormalities after SCI, but there is a risk for a fracture to the osteoporotic skeletal system. The goal of this study was to determine if low force stimulation (3 Hz) causes fatigue of chronically paralyzed muscle consistent ...

  18. Evaluation of motor control following thenar muscle fatigue using symmetrical index

    Talebian S

    2009-08-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Muscle weakness and fatigue are two factors that cause muscle injuries. The roll of motor control is important in regulation and reduction of this effect. Repetition of motion after muscle fatigue is due to the significant role of motor control system. The aim of this study was to evaluate the quality of roll control of central nervous system following fatigue in order to answer primary questions in therapeutic exercises."n"n Methods: Twenty voluntary healthy subjects participated in this study. Dominant abductor policis brevis after surface electromyography (SEMG of maximal voluntary contraction (MVC fatigued by maximum three minutes isometric contraction in specific hand splint monitored by dynamometer until reduction of activities to 50% MVC. Before and immediately after fatigue test, 5 dynamic full range of motion in abduction direction performed without resistance and muscle activities recorded by SEMG. Three middle muscle activities selected for comparison of Symmetrical Index (SI as specificity of motor control assessment. Fatigue indicators were percentage of reduction of MVC and median and mean frequency of power spectrum of MVC before and after fatigue test."n"n Results: Significant reduction of

  19. Blood flow restricted and traditional resistance training performed to fatigue produce equal muscle hypertrophy.

    Farup, J; de Paoli, F; Bjerg, K; Riis, S; Ringgard, S; Vissing, K

    2015-12-01

    This study investigated the hypertrophic potential of load-matched blood-flow restricted resistance training (BFR) vs free-flow traditional resistance training (low-load TRT) performed to fatigue. Ten healthy young subjects performed unilateral BFR and contralateral low-load TRT elbow flexor dumbbell curl with 40% of one repetition maximum until volitional concentric failure 3 days per week for 6 weeks. Prior to and at 3 (post-3) and 10 (post-10) days post-training, magnetic resonance imaging (MRI) was used to estimate elbow flexor muscle volume and muscle water content accumulation through training. Acute changes in muscle thickness following an early vs a late exercise bout were measured with ultrasound to determine muscle swelling during the immediate 0-48 h post-exercise. Total work was threefold lower for BFR compared with low-load TRT (P BRF and low-load TRT increased muscle volume by approximately 12% at post-3 and post-10 (P BRF (P < 0.05) in the early training phase. In conclusion, BFR and low-load TRT, when performed to fatigue, produce equal muscle hypertrophy, which may partly rely on transient exercise-induced increases in muscle water content. PMID:25603897

  20. Fatigue

    ... to help you find out what's causing your fatigue and recommend ways to relieve it. Fatigue itself is not a disease. Medical problems, treatments, and personal habits can add to fatigue. These include Taking certain medicines, such as antidepressants, ...

  1. Muscle fatigue monitoring using a multifrequency bioimpedance technique

    VESCIO, GIOVANNI; Rosell Ferrer, Francisco Javier; Nescolarde Selva, Lexa Digna; Giovinazzo, Giuseppe

    2011-01-01

    The objective of this work is to measure the changes of electrical bioimpedance module and phase related to muscular fatigue. The results could also be interesting for medical diagnosis of leg oedema, related to heart diseases, or muscular lesions. With this purpose in mind we have done multifrequency bioimpedance measurements on volunteers to evaluate the change of the impedance due to some physical exercises with the leg and with the arm. In the case of the measures performed on the a...

  2. The difference between standing and sitting in 3 different seat inclinations on abdominal muscle activity and chest and abdominal expansion in woodwind and brass musicians

    Bronwen Jane Ackermann

    2014-08-01

    Full Text Available Wind instrumentalists require a sophisticated functioning of their respiratory system to control their air stream, which provides the power for optimal musical performance. The air supply must be delivered into the instrument in a steady and controlled manner and with enough power by the action of the expiratory musculature to produce the desired level of sound at the correct pitch. It is suggested that playing posture may have an impact on the abdominal muscle activity controlling this expired air, but there is no research on musicians to support this theory. This study evaluated chest and abdominal expansion, via respiratory inductive plethysmography, as well as activation patterns of lower and upper abdominal musculature, using surface electromyography, during performance of a range of typical orchestral repertoire by 113 woodwind and brass players. Each of the five orchestral excerpts was played in one of four randomly allocated postures: standing; sitting flat; sitting inclined forwards; and sitting inclined backwards.Musicians showed a clear preference for playing in standing rather than sitting. In standing, the chest expansion range and maximum values were greater (p<0.01, while the abdominal expansion was less than in all sitting postures (p<0.01. Chest expansion patterns did not vary between the three sitting postures, while abdominal expansion was reduced in the forward inclined posture compared to the other sitting postures (p<0.05. There was no significant variation in abdominal muscle activation between the sitting postures, but the level of activation in sitting was only 2/3 of the significantly higher level observed in standing (p<0.01.This study has demonstrated significant differences in respiratory mechanics between sitting and standing postures in wind musicians during playing of typical orchestral repertoire. Further research is needed to clarify the complex respiratory mechanisms supporting musical performance.

  3. Facial Video based Detection of Physical Fatigue for Maximal Muscle Activity

    Haque, Mohammad Ahsanul; Irani, Ramin; Nasrollahi, Kamal; Moeslund, Thomas B.

    2016-01-01

    Physical fatigue reveals the health condition of a person at for example health checkup, fitness assessment or rehabilitation training. This paper presents an efficient noncontact system for detecting non-localized physi-cal fatigue from maximal muscle activity using facial videos acquired in a...... realistic environment with natural lighting where subjects were allowed to voluntarily move their head, change their facial expression, and vary their pose. The proposed method utilizes a facial feature point tracking method by combining a ‘Good feature to track’ and a ‘Supervised descent method’ to address...

  4. Evidence of long term muscle fatigue following prolonged intermittent contractions based on mechano- and electromyograms

    Søgaard, K; Blangsted, A K; Jørgensen, L V;

    2003-01-01

    performance of the biceps muscle are more strongly reflected in low than in high force test contractions, more prominent in the MMG than in the EMG signal and less pronounced following contractions controlled by visual compared to proprioceptive feedback. Further, it was investigated if fatigue induced by 30...... visual and proprioceptive feedback. EMG, MMG, and force were evaluated during isometric test contractions at 5% and 80% MVC before prolonged contraction and after 10 and 30 min of recovery. MVC decreased significantly after the fatiguing exercise in all three sessions and was still decreased even after...

  5. Potential of M-Wave Elicited by Double Pulse for Muscle Fatigue Evaluation in Intermittent Muscle Activation by Functional Electrical Stimulation for Motor Rehabilitation

    Naoto Miura; Takashi Watanabe

    2016-01-01

    Clinical studies on application of functional electrical stimulation (FES) to motor rehabilitation have been increasing. However, muscle fatigue appears early in the course of repetitive movement production training by FES. Although M-wave variables were suggested to be reliable indices of muscle fatigue in long lasting constant electrical stimulation under the isometric condition, the ability of M-wave needs more studies under intermittent stimulation condition, because the intervals between...

  6. Carnitine Acetyltransferase Mitigates Metabolic Inertia and Muscle Fatigue during Exercise.

    Seiler, Sarah E; Koves, Timothy R; Gooding, Jessica R; Wong, Kari E; Stevens, Robert D; Ilkayeva, Olga R; Wittmann, April H; DeBalsi, Karen L; Davies, Michael N; Lindeboom, Lucas; Schrauwen, Patrick; Schrauwen-Hinderling, Vera B; Muoio, Deborah M

    2015-07-01

    Acylcarnitine metabolites have gained attention as biomarkers of nutrient stress, but their physiological relevance and metabolic purpose remain poorly understood. Short-chain carnitine conjugates, including acetylcarnitine, derive from their corresponding acyl-CoA precursors via the action of carnitine acetyltransferase (CrAT), a bidirectional mitochondrial matrix enzyme. We show here that contractile activity reverses acetylcarnitine flux in muscle, from net production and efflux at rest to net uptake and consumption during exercise. Disruption of this switch in mice with muscle-specific CrAT deficiency resulted in acetyl-CoA deficit, perturbed energy charge, and diminished exercise tolerance, whereas acetylcarnitine supplementation produced opposite outcomes in a CrAT-dependent manner. Likewise, in exercise-trained compared to untrained humans, post-exercise phosphocreatine recovery rates were positively associated with CrAT activity and coincided with dramatic shifts in muscle acetylcarnitine dynamics. These findings show acetylcarnitine serves as a critical acetyl buffer for working muscles and provide insight into potential therapeutic strategies for combatting exercise intolerance. PMID:26154055

  7. Effects of Co-contraction of Both Transverse Abdominal Muscle and Pelvic Floor Muscle Exercises for Stress Urinary Incontinence: A Randomized Controlled Trial

    Tajiri, Kimiko; Huo, Ming; Maruyama, Hitoshi

    2014-01-01

    [Purpose] The purpose of this study was to devise a new urinary incontinence exercise using co-contraction of both the transverse abdominal muscle (TA) and pelvic floor muscle (PFM) and examine the intervention effect in middle-aged women with stress urinary incontinence (SUI). [Subjects] The subjects were fifteen women with SUI who were divided into two groups: the TA and PFM co-contraction exercise group (n=9) and the control group (n=6). [Methods] Participants in the exercise group perform...

  8. Effects of plantar-flexor muscle fatigue on the magnitude and regularity of center-of-pressure fluctuations

    Roerdink, M.; Hlavackova, P.; Vuillerme, N.

    2011-01-01

    Control of bipedal posture is highly automatized but requires attentional investment, the amount of which varies between participants and with postural constraints, such as plantar-flexor muscle fatigue. Elevated attentional demands for standing with fatigued plantar flexors have been demonstrated u

  9. An analysis of the activity and muscle fatigue of the muscles around the neck under the three most frequent postures while using a smartphone

    Choi, Jung-Hyun; Jung, Min-Ho; Yoo, Kyung-Tae

    2016-01-01

    [Purpose] The purpose of this study was to identify changes in the activity and fatigue of the splenius capitis and upper trapezius muscles, which are agonists to the muscles supporting the head, under the three postures most frequently adopted while using a smartphone. [Subjects and Methods] The subjects were 15 college students in their 20s. They formed a single group and had to adopt three different postures (maximum bending, middle bending, and neutral). While the 15 subjects maintained the postures, muscle activity and fatigue were measured using surface electromyography. [Results] Comparison of the muscle fatigue caused by each posture showed statistically significant differences for the right splenius capitis, left splenius capitis, and left upper trapezius muscles. In addition, maintaining the maximum bending posture while using a smartphone resulted in higher levels of fatigue in the right splenius capitis, left splenius capitis, and left upper trapezius muscles compared with those for the middle bending posture. [Conclusion] Therefore, this study suggests that individuals should bend their neck slightly when using a smartphone, rather than bending it too much, or keep their neck straight to reduce fatigue of the cervical erector muscles. PMID:27313393

  10. An analysis of the activity and muscle fatigue of the muscles around the neck under the three most frequent postures while using a smartphone.

    Choi, Jung-Hyun; Jung, Min-Ho; Yoo, Kyung-Tae

    2016-05-01

    [Purpose] The purpose of this study was to identify changes in the activity and fatigue of the splenius capitis and upper trapezius muscles, which are agonists to the muscles supporting the head, under the three postures most frequently adopted while using a smartphone. [Subjects and Methods] The subjects were 15 college students in their 20s. They formed a single group and had to adopt three different postures (maximum bending, middle bending, and neutral). While the 15 subjects maintained the postures, muscle activity and fatigue were measured using surface electromyography. [Results] Comparison of the muscle fatigue caused by each posture showed statistically significant differences for the right splenius capitis, left splenius capitis, and left upper trapezius muscles. In addition, maintaining the maximum bending posture while using a smartphone resulted in higher levels of fatigue in the right splenius capitis, left splenius capitis, and left upper trapezius muscles compared with those for the middle bending posture. [Conclusion] Therefore, this study suggests that individuals should bend their neck slightly when using a smartphone, rather than bending it too much, or keep their neck straight to reduce fatigue of the cervical erector muscles. PMID:27313393

  11. Assessment of skeletal muscle fatigue of road maintenance workers based on heart rate monitoring and myotonometry

    Kalkis Henrijs

    2006-07-01

    Full Text Available Abstract Objective This research work is dedicated to occupational health problems caused by ergonomic risks. The research object was road building industry, where workers have to work very intensively, have long work hours, are working in forced/constrained work postures and overstrain during the work specific parts of their bodies. The aim of this study was to evaluate the work heaviness degree and to estimate the muscle fatigue of workers after one week work cycle. The study group consisted of 10 road construction and maintenance workers and 10 pavers aged between 20 and 60 years. Methods Physical load were analyzed by measuring heart rate (HR, work postures (OWAS and perceived exertion (RPE. Assessments of the muscles strain and functional state (tone were carried out using myotonometric (MYO measurements. The reliability of the statistical processing of heart rate monitoring and myotonometry data was determined using correlating analysis. Results This study showed that that road construction and repairing works should be considered as a hard work according to average metabolic energy consumption 8.1 ± 1.5 kcal/min; paving, in its turn, was a moderately hard work according to 7.2 ± 1.1 kcal/min. Several muscle tone levels were identified allowing subdivision of workers into three conditional categories basing on muscle tone and fatigue: I – absolute muscle relaxation and ability to relax; II – a state of equilibrium, when muscles are able to adapt to the work load and are partly able to relax; and III – muscle fatigue and increased tone. It was also found out that the increase of muscle tone and fatigue mainly depend on workers physical preparedness and length of service, and less – on their age. Conclusion We have concluded that a complex ergonomic analysis consisting of heart rate monitoring, assessment of compulsive working postures and myotonometry is appropriate to assess the work heaviness degree and can provide prognosis of

  12. Changes in Serum Free Amino Acids and Muscle Fatigue Experienced during a Half-Ironman Triathlon.

    Francisco Areces

    Full Text Available The aim of this study was to investigate the relationship between changes in serum free amino acids, muscle fatigue and exercise-induced muscle damage during a half-ironman triathlon. Twenty-six experienced triathletes (age = 37.0 ± 6.8 yr; experience = 7.4 ± 3.0 yr competed in a real half-ironman triathlon in which sector times and total race time were measured by means of chip timing. Before and after the race, a countermovement jump and a maximal isometric force test were performed, and blood samples were withdrawn to measure serum free amino acids concentrations, and serum creatine kinase levels as a blood marker of muscle damage. Total race time was 320 ± 37 min and jump height (-16.3 ± 15.2%, P 20%. However, neither the changes in serum free amino acids nor the tryptophan/BCAA ratio were related muscle fatigue or muscle damage during the race.

  13. Glutathione supplementation suppresses muscle fatigue induced by prolonged exercise via improved aerobic metabolism

    AOI, WATARU; Ogaya, Yumi; Takami, Maki; Konishi, Toru; Sauchi, Yusuke; Park, Eun Young; Wada, Sayori; Sato, Kenji; Higashi, Akane

    2015-01-01

    Backgrounds Glutathione is an endogenous redox couple in animal cells and plays important roles in antioxidant defense and detoxification, although it is unknown if oral glutathione supplementation affects exercise-induced physiological changes. The present study investigated the effect of glutathione intake on exercise-induced muscle metabolism and fatigue in mice and humans. Methods ICR mice were divided into 4 groups: sedentary control, sedentary supplemented with glutathione (2.0%, 5 μL/g...

  14. Glutathione supplementation suppresses muscle fatigue induced by prolonged exercise via improved aerobic metabolism

    AOI, WATARU; Ogaya, Yumi; Takami, Maki; Konishi, Toru; Sauchi, Yusuke; Park, Young Y.; Wada, Sayori; Sato, Kenji; Higashi, Akane

    2015-01-01

    Backgrounds: Glutathione is an endogenous redox couple in animal cells and plays important roles in antioxidant defense and detoxification, although it is unknown if oral glutathione supplementation affects exercise-induced physiological changes. The present study investigated the effect of glutathione intake on exercise-induced muscle metabolism and fatigue in mice and humans. Methods: ICR mice were divided into 4 groups: sedentary control, sedentary supplemented with glutathione (2.0%, 5μL/...

  15. Regional differences of [18F]-FDG uptake within the brain during fatiguing muscle contractions

    Kindred, John H.; Kalliokoski, Kari K.; Bojsen-Møller, Jens; Rudroff, Thorsten

    2015-01-01

    Background and Purpose Many studies have shown that a position task is more difficult than a force task although both are performed at a similar net muscle force. Thus, the time to task failure is consistently shown to be briefer during the position task. The contributions of the central nervous system to these two types of fatiguing contractions are not completely understood. The purpose of this pilot study was to examine differences in regional brain activity between force and position task...

  16. Regional differences of [18F]-FDG uptake within the brain during fatiguing muscle contractions.

    Kindred, John H.; Kalliokoski, Kari K.; Bojsen-Møller, Jens; Rudroff, Thorsten

    2015-01-01

    Background and Purpose: Many studies have shown that a position task is more difficult than a force task although both are performed at a similar net muscle force. Thus, the time to task failure is consistently shown to be briefer during the position task. The contributions of the central nervous system to these two types of fatiguing contractions are not completely understood. The purpose of this pilot study was to examine differences in regional brain activity between force and position tas...

  17. Effect of Lactate Accumulation during Exercise-induced Muscle Fatigue on the Sensorimotor Cortex

    Ishii, Hideaki; Nishida, Yusuke

    2014-01-01

    [Purpose] During exercise, skeletal muscle motor units are recruited based on afferent sensory input following peripheral metabolic by-product accumulation. The purpose of this study was to investigate whether lactate plays a role in conveying fatigue-related information to the brain. [Subjects] Eleven healthy adults participated in this study. [Methods] Subjects performed handgrip exercises at 10%, 30%, and 50% maximal voluntary contraction for 120 s. They were monitored for brachial artery ...

  18. Effect of Expiratory Muscle Fatigue on the Respiratory Response during Exercise

    Sugiura, Hiromichi; Sako, Shunji; Oshida, Yoshiharu

    2013-01-01

    [Purpose] The aim of this study was to reveal the effect of expiratory muscle fatigue (EMF) on respiratory response under two different exercise conditions: exercise (EX) with EMF (EMF-EX) and control EX without EMF (CON-EX). [Methods] Nine healthy adult men performed cycle exercise with a ramp load, and a spirometer was used to measure forced vital capacity (FVC), forced expiratory volume in one second, percent of forced expiratory volume, maximal expiratory mouth pressure, and maximal inspi...

  19. Extrapulmonary features of bronchiectasis: muscle function, exercise capacity, fatigue, and health status

    Ozalp Ozge; Inal-Ince Deniz; Calik Ebru; Vardar-Yagli Naciye; Saglam Melda; Savci Sema; Arikan Hulya; Bosnak-Guclu Meral; Coplu Lutfi

    2012-01-01

    Abstract Background There are limited number of studies investigating extrapulmonary manifestations of bronchiectasis. The purpose of this study was to compare peripheral muscle function, exercise capacity, fatigue, and health status between patients with bronchiectasis and healthy subjects in order to provide documented differences in these characteristics for individuals with and without bronchiectasis. Methods Twenty patients with bronchiectasis (43.5 ± 14.1 years) and 20 healthy subjects ...

  20. Physical Education Students’ Knowledge of Selected Safe and Non-Recommended Exercises Strengthening the Abdominal Muscles

    Kędra Agnieszka

    2016-03-01

    Full Text Available Introduction. The aim of the study was to assess final-year physical education (PE students’ knowledge of exercises strengthening the abdominal muscles which are used in the introductory part of a PE lesson. Material and methods. The research involved 467 final-year physical education students. The group examined included undergraduate (Bachelor and postgraduate (Master students from four universities in Poland. A knowledge test with photographs was used to conduct the study. The students completed the knowledge test with one of the authors present. If the students had any questions regarding the exercises included in the test, they were demonstrated by the person in the photographs. The data were analysed using the Mann- Whitney-Wilcoxon test. Kendall’s concordance coefficient was used to assess reliability and measure the agreement between the opinions of a group of experts who were asked to rate the exercises in terms of their safety and effectiveness. The calculations were made with the use of statistical and calculation software (SPSS 9.0 for Windows. An alpha value < 0.05 was accepted as the level of significance of differences between the groups of undergraduate and postgraduate students. Results. Eighty-two participants (17.6% performed the task correctly, selecting all the safe exercises, 139 students (29.8% made one error, while 110 marked all the overloading and ineffective exercises as safe. Conclusions. The students’ knowledge of safe exercises strengthening the abdominal muscles was insufficient. Both undergraduate and postgraduate students demonstrated similar knowledge concerning these exercises.

  1. Physiological functions of the effects of the different bathing method on recovery from local muscle fatigue

    Lee Soomin

    2012-09-01

    Full Text Available Abstract Background Recently, mist saunas have been used in the home as a new bathing style in Japan. However, there are still few reports on the effects of bathing methods on recovery from muscle fatigue. Furthermore, the effect of mist sauna bathing on human physiological function has not yet been revealed. Therefore, we measured the physiological effects of bathing methods including the mist sauna on recovery from muscle fatigue. Methods The bathing methods studied included four conditions: full immersion bath, shower, mist sauna, and no bathing as a control. Ten men participated in this study. The participants completed four consecutive sessions: a 30-min rest period, a 10-min all out elbow flexion task period, a 10-min bathing period, and a 10-min recovery period. We evaluated the mean power frequency (MNF of the electromyogram (EMG, rectal temperature (Tre, skin temperature (Tsk, skin blood flow (SBF, concentration of oxygenated hemoglobin (O2Hb, and subjective evaluation. Results We found that the MNF under the full immersion bath condition was significantly higher than those under the other conditions. Furthermore, Tre, SBF, and O2Hb under the full immersion bath condition were significantly higher than under the other conditions. Conclusions Following the results for the full immersion bath condition, the SBF and O2Hb of the mist sauna condition were significantly higher than those for the shower and no bathing conditions. These results suggest that full immersion bath and mist sauna are effective in facilitating recovery from muscle fatigue.

  2. Changes in muscle strength and pain in response to surgical repair of posterior abdominal wall disruption followed by rehabilitation

    Hemingway, A; Herrington, L; Blower, A

    2003-01-01

    Background: Posterior abdominal wall deficiency (PAWD) is a tear in the external oblique aponeurosis or the conjoint tendon causing a posterior wall defect at the medial end of the inguinal canal. It is often known as sportsman's hernia and is believed to be caused by repetitive stress. Objective: To assess lower limb and abdominal muscle strength of patients with PAWD before intervention compared with matched controls; to evaluate any changes following surgical repair and rehabilitation. Methods: Sixteen subjects were assessed using a questionnaire, isokinetic testing of the lower limb strength, and pressure biofeedback testing of the abdominals. After surgery and a six week rehabilitation programme, the subjects were re-evaluated. A control group were assessed using the same procedure. Results: Quadriceps and hamstrings strength was not affected by this condition. A deficit hip muscle strength was found on the affected limb before surgery, which was significant for the hip flexors (p = 0.05). Before surgery, 87% of the patients compared with 20% of the controls failed the abdominal obliques test. Both the injured and non-injured sides had improved significantly in strength after surgery and rehabilitation. The strength of the abdominal obliques showed the most significant improvement over the course of the rehabilitation programme. Conclusions: Lower limb muscle strength may have been reduced as the result of disuse atrophy or pain inhibition. Abdominal oblique strength was deficient in the injured patients and this compromises rotational control of the pelvis. More sensitive investigations (such as electromyography) are needed to assess the link between abdominal oblique function and groin injury. PMID:12547744

  3. Acute fatigue impairs neuromuscular activity of anterior cruciate ligament-agonist muscles in female team handball players

    Zebis, M K; Bencke, J; Andersen, L L; Alkjaer, T; Suetta, C; Mortensen, P; Kjaer, M; Aagaard, P

    2011-01-01

    In sports, like team handball, fatigue has been associated with an increased risk of anterior cruciate ligament (ACL) injury. While effects of fatigue on muscle function are commonly assessed during maximal isometric voluntary contraction (MVC), such measurements may not relate to the muscle...... function during match play. The purpose of this study was to investigate the effect of muscle fatigue induced by a simulated handball match on neuromuscular strategy during a functional sidecutting movement, associated with the incidence of ACL injury. Fourteen female team handball players were tested for...... the simulated handball match induced a decrease in MVC strength for both the quadriceps and hamstring muscles (P<0.05), a selective decrease in hamstring neuromuscular activity was seen during sidecutting (P<0.05). This study shows impaired ACL-agonist muscle (i.e. hamstring) activity during...

  4. Time course of the cross-over effect of fatigue on the contralateral muscle after unilateral exercise.

    Aude-Clémence M Doix

    Full Text Available We investigated the cross-over effect of muscle fatigue and its time course on the non-exercising contralateral limb (NEL after unilateral fatiguing contractions of the ipsilateral exercising limb (EL. For this purpose, 15 males performed two bouts of 100-second maximal isometric knee extensions with the exercising limb, and neuromuscular function of both the EL and NEL was assessed before (PRE, after a first fatiguing exercise (MID and after a second fatiguing exercise (POST. Maximal voluntary isometric torque production declined in the EL after the first bout of exercise (-9.6%; p<0.001 while in the NEL, the decrease occurred after the second bout of exercise (-10.6%; p<0.001. At MID, torque decline of the EL was strictly associated to an alteration of the mechanical twitch properties evoked by neurostimulation of the femoral nerve (i.e., peak twitch torque, maximal rate of twitch development. According to these markers, we suggest that peripheral fatigue occurred. At POST, after the second bout of exercise, the voluntary activation level of the knee extensor muscles was altered from PRE (-9.1%; p<0.001, indicating an overall central failure in both the EL and NEL. These findings indicate that two bouts of unilateral fatiguing exercise were needed to induce a cross-over effect of muscle fatigue on the non-exercising contralateral limb. Differential adjustments of the motor pathway (peripheral fatigue vs. central fatigue might contribute to the respective torque decline in the EL and the NEL. Given that our unilateral fatiguing exercise induced immediate maximal torque reduction in the EL and postponed the loss of torque production in the NEL, it is also concluded that the time course of muscle fatigue differed between limbs.

  5. Orientation, anisotropy, clustering, and volume fraction of smooth muscle cells within the wall of porcine abdominal aorta

    Tonar Z.

    2008-11-01

    Full Text Available We analyzed tissue samples of the normal porcine abdominal aorta using stereological assessment of histological sections through the tunica media layer. The results demonstrated that the local volume fraction of smooth muscle cells within tunica media does not differ among samples taken round the circumference of the artery, and that volume fraction can be assessed in sections stained with green trichrome as well as with immunohistochemistry against actin. The distribution of angles between the long axes of nuclei of the smooth muscle cells and the radial direction was different from normal. The profiles of smooth muscle cells were distributed in an isotropic, but an inhomogeneous manner.

  6. Comparison of deep and superficial abdominal muscle activity between experienced Pilates and resistance exercise instructors and controls during stabilization exercise.

    Moon, Ji-Hyun; Hong, Sang-Min; Kim, Chang-Won; Shin, Yun-A

    2015-06-01

    Pilates and resistance exercises are used for lumbar stabilization training. However, it is unclear which exercise is more effective for lumbar stabilization. In our study, we aimed to compare surface muscle activity and deep muscle thickness during relaxation and spinal stabilization exercise in experienced Pilates and resistance exercise instructors. This study is a retrospective case control study set in the Exercise Prescription Laboratory and Sports Medicine Center. The participants included Pilates instructors (mean years of experience, 3.20±1.76; n=10), resistance exercise instructors (mean years of experience, 2.53±0.63; n=10), and controls (n=10). The participants performed 4 different stabilization exercises: abdominal drawing-in maneuver, bridging, roll-up, and one-leg raise. During the stabilization exercises, surface muscle activity was measured with electromyography, whereas deep muscle thickness was measured by ultrasound imaging. During the 4 stabilization exercises, the thickness of the transverse abdominis (TrA) was significantly greater in the Pilates-trained group than the other 2 other groups. The internal oblique (IO) thickness was significantly greater in the Pilates- and resistance-trained group than the control group, during the 4 exercises. However, the surface muscle activities were similar between the groups. Both Pilates and resistance exercise instructors had greater activation of deep muscles, such as the TrA and IO, than the control subjects. Pilates and resistance exercise are both effective for increasing abdominal deep muscle thickness. PMID:26171383

  7. Tongue-placed tactile biofeedback suppresses the deleterious effects of muscle fatigue on joint position sense at the ankle

    Vuillerme, Nicolas; Chenu, Olivier; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    Whereas the acuity of the position sense at the ankle can be disturbed by muscle fatigue, it recently also has been shown to be improved, under normal ankle neuromuscular state, through the use of an artificial tongue-placed tactile biofeedback. The underlying principle of this biofeedback consisted of supplying individuals with supplementary information about the position of their matching ankle position relative to their reference ankle position through electrotactile stimulation of the tongue. Within this context, the purpose of the present experiment was to investigate whether this biofeedback could mitigate the deleterious effect of muscle fatigue on joint position sense at the ankle. To address this objective, sixteen young healthy university students were asked to perform an active ankle-matching task in two conditions of No-fatigue and Fatigue of the ankle muscles and two conditions of No-biofeedback and Biofeedback. Measures of the overall accuracy and the variability of the positioning were determin...

  8. Contribution of respiratory muscle blood flow to exercise-induced diaphragmatic fatigue in trained cyclists

    Vogiatzis, Ioannis; Athanasopoulos, Dimitris; Boushel, Robert Christopher;

    2008-01-01

    exercise tests at inspired O(2) fractions (FIO2) of 0.13, 0.21 and 1.00 in balanced order. Work rates were selected to produce the same tidal volume, breathing frequency and respiratory muscle load at each FIO2 (63 +/- 1, 78 +/- 1 and 87 +/- 1% of normoxic maximal work rate, respectively). Intercostals......We investigated whether the greater degree of exercise-induced diaphragmatic fatigue previously reported in highly trained athletes in hypoxia (compared with normoxia) could have a contribution from limited respiratory muscle blood flow. Seven trained cyclists completed three constant load 5 min......(-1) and 95.1 +/- 7.8 ml (100 ml)(-1) min(-1), respectively). Neither IMBF was different across hypoxia, normoxia and hyperoxia (53.6 +/- 8.5, 49.9 +/- 5.9 and 52.9 +/- 5.9 ml (100 ml)(-1) min(-1), respectively). We conclude that when respiratory muscle energy requirement is not different between...

  9. Effects of High-Intensity Blood Flow Restriction Exercise on Muscle Fatigue

    Neto Gabriel R.

    2014-07-01

    Full Text Available Strength training combined with blood flow restriction (BFR have been used to improve the levels of muscle adaptation. The aim of this paper was to investigate the acute effect of high intensity squats with and without blood flow restriction on muscular fatigue levels. Twelve athletes (aged 25.95 ± 0.84 years were randomized into two groups: without Blood Flow Restriction (NFR, n = 6 and With Blood Flow Restriction (WFR, n = 6 that performed a series of free weight squats with 80% 1-RM until concentric failure. The strength of the quadriceps extensors was assessed in a maximum voluntary isometric contraction integrated to signals from the surface electromyogram. The average frequency showed significant reductions in the WFR group for the vastus lateralis and vastus medialis muscles, and intergroup only for the vastus medialis. In conclusion, a set of squats at high intensity with BFR could compromise muscle strength immediately after exercise, however, differences were not significant between groups.

  10. Measuring mechanical properties, including isotonic fatigue, of fast and slow MLC/mIgf-1 transgenic skeletal muscle.

    Del Prete, Zaccaria; Musarò, Antonio; Rizzuto, Emanuele

    2008-07-01

    Contractile properties of fast-twitch (EDL) and slow-twitch (soleus) skeletal muscles were measured in MLC/mIgf-1 transgenic and wild-type mice. MLC/mIgf-1 mice express the local factor mIgf-1 under the transcriptional control of MLC promoter, selectively activated in fast-twitch muscle fibers. Isolated muscles were studied in vitro in both isometric and isotonic conditions. We used a rapid "ad hoc" testing protocol that measured, in a single procedure, contraction time, tetanic force, Hill's (F-v) curve, power curve and isotonic muscle fatigue. Transgenic soleus muscles did not differ from wild-type with regard to any measured variable. In contrast, transgenic EDL muscles displayed a hypertrophic phenotype, with a mass increase of 29.2% compared to wild-type. Absolute tetanic force increased by 21.5% and absolute maximum power by 34.1%. However, when normalized to muscle cross-sectional area and mass, specific force and normalized power were the same in transgenic and wild-type EDL muscles, revealing that mIgf-1 expression induces a functional hypertrophy without altering fibrotic tissue accumulation. Isotonic fatigue behavior did not differ between transgenic and wild-type muscles, suggesting that the ability of mIgf-1 transgenic muscle to generate a considerable higher absolute power did not affect its resistance to fatigue. PMID:18415017

  11. Red (660 nm) and infrared (830 nm) low-level laser therapy in skeletal muscle fatigue in humans: what is better?

    de Almeida, Patrícia; Lopes-Martins, Rodrigo Álvaro Brandão; De Marchi, Thiago; Tomazoni, Shaiane Silva; Bjordal, Jan Magnus

    2011-01-01

    In animal and clinical trials low-level laser therapy (LLLT) using red, infrared and mixed wavelengths has been shown to delay the development of skeletal muscle fatigue. However, the parameters employed in these studies do not allow a conclusion as to which wavelength range is better in delaying the development of skeletal muscle fatigue. With this perspective in mind, we compared the effects of red and infrared LLLT on skeletal muscle fatigue. A randomized double-blind placebo-controlled cr...

  12. Correlation between vitamin D levels and muscle fatigue risk factors based on physical activity in healthy older adults

    Al-Eisa, Einas S; Alghadir, Ahmad H; Gabr, Sami A

    2016-01-01

    Purpose The purpose of this study was to investigate the relationship of serum vitamin D levels with physical activity, obesity, muscle fatigue biomarkers, and total antioxidant capacity (TAC) in healthy older adults. Methods A total of 85 healthy older subjects aged 64–96 years were recruited in this study. Based on estimated energy expenditure scores, the participants were classified into three groups: inactive (n=25), moderate (n=20), and physically active (n=35). Serum 25(OH)D (25-hydroxy vitamin D) levels, metabolic syndrome parameters, TAC activity, muscle fatigue biomarkers (Ca, creatine kinase, lactic acid dehydrogenase, troponin I, hydroxyproline), physical activity, body fatness, and fatigue score (visual analog scale) were estimated using immunoassay techniques and prevalidated questionnaires, respectively. Results Physical activity was estimated in 64.6% of the participants. Males showed higher physical activity (42.5%) compared to females (26.25%). Compared to participants with lower activity, significant reduction in body mass index, waist circumference, hips, fasting blood sugar, triglycerides, total cholesterol, HDL-cholesterol, and LDL-cholesterol were observed in moderate and physically active participants. Also, significant increase in the levels of serum 25(OH)D concentrations, calcium, and TAC activity along with reduction in the levels of muscle fatigue biomarkers: creatine kinase, lactic acid dehydrogenase, troponin I, hydroxyproline, and fatigue scores (visual analog scale) were reported in physically active participants compared to those of lower physical activity. In all participants, serum 25(OH)D concentrations correlated positively with Ca, TAC, physical activity scores, and negatively with body mass index, lipid profile, fatigue scores (visual analog scale), and muscle fatigue biomarkers. Stepwise regression analysis showed that serum 25(OH)D concentrations, physical activity, Ca, TAC, and demographic parameters explained

  13. Contribution of abdominal muscle strength to various activities of daily living of stroke patients with mild paralysis

    Fujita, Takaaki; Sato, Atsushi; Togashi, Yui; Kasahara, Ryuichi; Ohashi, Takuro; Yamamoto, Yuichi

    2015-01-01

    [Purpose] The trunk muscles frequently become weak after stroke, thus impacting overall activities of daily living. However, activities of daily living items closely related with trunk strength remain unclear. This study aimed to clarify the influence of trunk muscle weakness on activities of daily living items. [Subjects] The subjects were 24 stroke patients who fulfilled the following inclusion criteria: first stroke and the absence of severe paralysis, marked cognitive function deterioration, unilateral spatial neglect or apathy. [Methods] According to abdominal strength, the 24 patients were divided into a nonweakness group and a weakness group. For the assessment, we used the stroke impairment assessment set, the Berg balance scale, a simple test for evaluating hand function, grip strength, and functional independence measure scale scores and the results were compared between the groups. [Results] The Berg balance scale score and scores for dressing, toilet use, transfer to bed, and walk items of the functional independence measure were significantly lower in the weakness group than in the nonweakness group. [Conclusion] Our results suggest that weakness of the abdominal muscles adversely impacts the balance of patients with mild stroke as well as their ability to dress, use a toilet, transfer, and walk. Trunk training, including abdominal muscle exercises, can effectively improve the performance of these activities of daily living items. PMID:25931737

  14. Thickness of Rectus Abdominis Muscle and Abdominal Subcutaneous Fat Tissue in Adult Women: Correlation with Age, Pregnancy, Laparotomy, and Body Mass Index

    Jungmin Kim

    2012-09-01

    Full Text Available Background Rectus abdominis muscle and abdominal subcutaneous fat tissue are usefulfor reconstruction of the chest wall, and abdominal, vaginal, and perianal defects. Thus,preoperative evaluation of rectus abdominis muscle and abdominal subcutaneous fat tissue isimportant. This is a retrospective study that measured the thickness of rectus abdominis muscleand abdominal subcutaneous fat tissue using computed tomography (CT and analyzed thecorrelation with the patients’ age, gestational history, history of laparotomy, and body massindex (BMI.Methods A total of 545 adult women were studied. Rectus abdominis muscle and abdominalsubcutaneous fat thicknesses were measured with abdominopelvic CT. The results were analyzedto determine if the thickness of the rectus abdominis muscle or subcutaneous fat tissue wassignificantly correlated with age, number of pregnancies, history of laparotomy, and BMI.Results Rectus abdominis muscle thicknesses were 9.58 mm (right and 9.73 mm (left at thexiphoid level and 10.26 mm (right and 10.26 mm (left at the umbilicus level. Subcutaneousfat thicknesses were 24.31 mm (right and 23.39 mm (left. Rectus abdominismuscle thicknessdecreased with age and pregnancy. History of laparotomy had a significant negative correlationwith rectus abdominis muscle thickness at the xiphoid level. Abdominal subcutaneous fatthickness had no correlation with age, number of pregnancies, or history of laparotomy.Conclusions Age, gestational history, and history of laparotomy influenced rectus abdominismuscle thickness but did not influence abdominal subcutaneous fat thickness. These results areclinically valuable for planning a rectus abdominis muscle flap and safe elevation of muscle flap.

  15. Low-level laser (light) therapy (LLLT) on muscle tissue: performance, fatigue and repair benefited by the power of light

    Ferraresi, Cleber; Hamblin, Michael R.; Parizotto, Nivaldo A.

    2012-01-01

    The use of low level laser (light) therapy (LLLT) has recently expanded to cover areas of medicine that were not previously thought of as the usual applications such as wound healing and inflammatory orthopedic conditions. One of these novel application areas is LLLT for muscle fatigue and muscle injury. Since it is becoming agreed that mitochondria are the principal photoacceptors present inside cells, and it is known that muscle cells are exceptionally rich in mitochondria, this suggests th...

  16. Blunted angiogenesis and hypertrophy are associated with increased fatigue resistance and unchanged aerobic capacity in old overloaded mouse muscle.

    Ballak, Sam B; Busé-Pot, Tinelies; Harding, Peter J; Yap, Moi H; Deldicque, Louise; de Haan, Arnold; Jaspers, Richard T; Degens, Hans

    2016-04-01

    We hypothesize that the attenuated hypertrophic response in old mouse muscle is (1) partly due to a reduced capillarization and angiogenesis, which is (2) accompanied by a reduced oxidative capacity and fatigue resistance in old control and overloaded muscles, that (3) can be rescued by the antioxidant resveratrol. To investigate this, the hypertrophic response, capillarization, oxidative capacity, and fatigue resistance of m. plantaris were compared in 9- and 25-month-old non-treated and 25-month-old resveratrol-treated mice. Overload increased the local capillary-to-fiber ratio less in old (15 %) than in adult (59 %) muscle (P muscles of old mice had a higher succinate dehydrogenase (SDH) activity (P < 0.05) and a slower fiber type profile (P < 0.05), the isometric fatigue resistance was similar in 9- and 25-month-old mice. In both age groups, the fatigue resistance was increased to the same extent after overload (P < 0.01), without a significant change in SDH activity, but an increased capillary density (P < 0.05). Attenuated angiogenesis during overload may contribute to the attenuated hypertrophic response in old age. Neither was rescued by resveratrol supplementation. Changes in fatigue resistance with overload and aging were dissociated from changes in SDH activity, but paralleled those in capillarization. This suggests that capillarization plays a more important role in fatigue resistance than oxidative capacity. PMID:26970774

  17. Localized Electrical Impedance Myography of the Biceps Brachii Muscle during Different Levels of Isometric Contraction and Fatigue.

    Li, Le; Shin, Henry; Li, Xiaoyan; Li, Sheng; Zhou, Ping

    2016-01-01

    This study assessed changes in electrical impedance myography (EIM) at different levels of isometric muscle contraction as well as during exhaustive exercise at 60% maximum voluntary contraction (MVC) until task failure. The EIM was performed on the biceps brachii muscle of 19 healthy subjects. The results showed that there was a significant difference between the muscle resistance (R) measured during the isometric contraction and when the muscle was completely relaxed. Post hoc analysis shows that the resistance increased at higher contractions (both 60% MVC and MVC), however, there were no significant changes in muscle reactance (X) during the isometric contractions. The resistance also changed during different stages of the fatigue task and there were significant decreases from the beginning of the contraction to task failure as well as between task failure and post fatigue rest. Although our results demonstrated an increase in resistance during isometric contraction, the changes were within 10% of the baseline value. These changes might be related to the modest alterations in muscle architecture during a contraction. The decrease in resistance seen with muscle fatigue may be explained by an accumulation of metabolites in the muscle tissue. PMID:27110795

  18. Localized Electrical Impedance Myography of the Biceps Brachii Muscle during Different Levels of Isometric Contraction and Fatigue

    Le Li

    2016-04-01

    Full Text Available This study assessed changes in electrical impedance myography (EIM at different levels of isometric muscle contraction as well as during exhaustive exercise at 60% maximum voluntary contraction (MVC until task failure. The EIM was performed on the biceps brachii muscle of 19 healthy subjects. The results showed that there was a significant difference between the muscle resistance (R measured during the isometric contraction and when the muscle was completely relaxed. Post hoc analysis shows that the resistance increased at higher contractions (both 60% MVC and MVC, however, there were no significant changes in muscle reactance (X during the isometric contractions. The resistance also changed during different stages of the fatigue task and there were significant decreases from the beginning of the contraction to task failure as well as between task failure and post fatigue rest. Although our results demonstrated an increase in resistance during isometric contraction, the changes were within 10% of the baseline value. These changes might be related to the modest alterations in muscle architecture during a contraction. The decrease in resistance seen with muscle fatigue may be explained by an accumulation of metabolites in the muscle tissue.

  19. Effect of ascorbic acid on fatigue of skeletal muscle fibres in long term cold exposed sprague dawley rats

    On exposure to prolonged cold temperature, the body responds for effective heat production both by shivering and non-shivering thermo genesis. Cold exposure increases the production of reactive oxygen species which influence the sarcoplasmic reticulum Ca/sup ++/ release from the skeletal muscles and affect their contractile properties. The role of ascorbic acid supplementation on force of contraction during fatigue of cold exposed skeletal muscles was evaluated in this study. Method: Ninety healthy, male Sprague Dawley rats were randomly divided into three groups of control, cold exposed, and cold exposed with ascorbic acid 500 mg/L supplementation mixed in drinking water. Group II and III were given cold exposure by keeping their cages in ice-filled tubs for 1 hr/day for one month. After one month, the extensor digitorum longus muscle was dissected out and force of contraction during fatigue in the skeletal muscle fibres was analysed on a computerised data acquisition system. Results: The cold exposed group showed a significant delay in the force of contraction during fatigue of skeletal muscle fibres compared to control group. Group III showed easy fatigability and a better force of contraction than the cold exposed group. Conclusions: Ascorbic acid increases the force of contraction and decreases resistance to fatigue in the muscles exposed to chronic cold. (author)

  20. Rats bred for low aerobic capacity become promptly fatigued and have slow metabolic recovery after stimulated, maximal muscle contractions.

    Sira Torvinen

    Full Text Available AIM: Muscular fatigue is a complex phenomenon affected by muscle fiber type and several metabolic and ionic changes within myocytes. Mitochondria are the main determinants of muscle oxidative capacity which is also one determinant of muscle fatigability. By measuring the concentrations of intracellular stores of high-energy phosphates it is possible to estimate the energy production efficiency and metabolic recovery of the muscle. Low intrinsic aerobic capacity is known to be associated with reduced mitochondrial function. Whether low intrinsic aerobic capacity also results in slower metabolic recovery of skeletal muscle is not known. Here we studied the influence of intrinsic aerobic capacity on in vivo muscle metabolism during maximal, fatiguing electrical stimulation. METHODS: Animal subjects were genetically heterogeneous rats selectively bred to differ for non-trained treadmill running endurance, low capacity runners (LCRs and high capacity runners (HCRs (n = 15-19. We measured the concentrations of major phosphorus compounds and force parameters in a contracting triceps surae muscle complex using (31P-Magnetic resonance spectroscopy ((31P-MRS combined with muscle force measurement from repeated isometric twitches. RESULTS: Our results demonstrated that phosphocreatine re-synthesis after maximal muscle stimulation was significantly slower in LCRs (p<0.05. LCR rats also became promptly fatigued and maintained the intramuscular pH poorly compared to HCRs. Half relaxation time (HRT of the triceps surae was significantly longer in LCRs throughout the stimulation protocol (p≤0.05 and maximal rate of torque development (MRTD was significantly lower in LCRs compared to HCRs from 2 min 30 s onwards (p≤0.05. CONCLUSION: We observed that LCRs are more sensitive to fatigue and have slower metabolic recovery compared to HCRs after maximal muscle contractions. These new findings are associated with reduced running capacity and with previously found

  1. Comparison of the effect of selected muscle groups fatigue on postural control during bipedal stance in healthy young women

    Zahra Rojhani Shirazi; Fatemeh Nikhalat Jahromi

    2013-01-01

    Background: The maintenance of balance is an essential requirement for the performance of daily tasks and sporting activities and muscular fatigue is a factor to impair postural control, so this study was done to compare the effect of selected muscle groups fatigue on postural control during bipedal stance in healthy subjects. Materials and Methods: Fifteen healthy female students (24.3 ± 2.6 years) completed three testing session with a break period of at least 2 days. During each session, p...

  2. Effect of ingested sodium bicarbonate on muscle force, fatigue, and recovery.

    Verbitsky, O; Mizrahi, J; Levin, M; Isakov, E

    1997-08-01

    The influence of acute ingestion of NaHCO3 on fatigue and recovery of teh quadriceps femoris muscle after exercise was studied in six healthy male subjects. A bicycle ergometer was used for exercising under three loading conditions: test A, load corresponding to maximal oxygen consumption; test B, load in test A + 17%; test C, load in test B but performed 1 h after acute ingestion of NaHCO3. Functional electrical stimulation (FES) was applied to provoke isometric contraction of the quadriceps femoris. The resulting knee torque was monitored during fatigue (2-min chronic FES) and recovery (10-s FES every 10 min, for 40 min). Quadriceps torques were higher in the presence of NaHCO3 (P < 0.05): with NaHCO3 the peak, residual, and recovery (after 40 min) normalized torques were, respectively, 0.68 +/- 0.05 (SD), 0.58 +/- 0.05, and 0.73 +/- 0.05; without NaHCO3 the values were 0.45 +/- 0.04, 0.30 +/- 0.06, and 0.63 +/- 0.06. The increased torques obtained after acute ingestion of NaHCO3 indicate the possible existence of improved nonoxidative glycolysis in isometric contraction, resulting in reduced fatigue and enhanced recovery. PMID:9296948

  3. Effect of Progressive Muscle Relaxation on the Fatigue and Quality of Life Among Iranian Aging Persons.

    Hassanpour-Dehkordi, Ali; Jalali, Amir

    2016-07-01

    Since the elderly population is increasing rapidly in developing countries which may decrease the physical activity and exercise and in turn could affect the elderly's quality of life, this study aimed to investigate the effect of progressive muscle relaxation on the elderly's quality of life in Iran. In a randomized clinical trial, participants were randomly divided into intervention and control groups. For the intervention group, muscular progressive relaxation was run three days per week for three months (totally 36 sessions). In relaxation, a patient contract a group of his/her muscles in each step and relaxes them after five seconds and finally loosens all muscles and takes five deep breaths. Each session lasts for 45 minutes. The instrument of data gathering consisted of questionnaires on individual's demographic data and quality of life SF-36. After intervention, quality of life increased significantly in the patients undergoing muscular progressive relaxation and fatigue severity decreased significantly in the intervention group compared to prior to intervention. In addition, there was a statistically significant difference in mean score of physical performance, restricted activity after physical problem, energy, socially function, physical pain, overall hygiene, and quality of life between intervention and control groups. By implementing regular and continuous progressive muscle relaxation, quality of life could be increased in different dimensions in the elderly and the context could be provided to age healthily and enjoy higher health and autonomy. Therefore, all of the therapeutic staffs are recommended to implement this plan to promote the elderly's quality of life. PMID:27424013

  4. Effect of thigh muscle fatigue on the biomechanical factors of the lower limbs when walking in a squatted position

    Hong, Wan-Ki; Lee, Chul-Gab; Ko, Dae-Sik

    2016-01-01

    [Purpose] The purpose of this study was to compare and analyze the effects of thigh muscle fatigue caused by walking in a squatted position on biomechanical factors, to evaluate the risk of a job performed sitting in a squatted position for a long period of time. [Subjects and Methods] Eighteen right foot dominant women without any injuries in their joints and body in the last 6 months were selected. They walked in a squatted position, and then muscle fatigue was induced by using an isokineti...

  5. Fatigue

    ... enough sleep, good nutrition, or a low-stress environment, it should be evaluated by your doctor. ... relax. Try yoga or meditation. Maintain a reasonable work and ... or depression, treating it often helps the fatigue. Be aware ...

  6. Fatigue

    ... chemotherapy and radiation Recovering from major surgery Anxiety, stress, or depression Staying up too late Drinking too much alcohol or too many caffeinated drinks Pregnancy One disorder that causes extreme fatigue is chronic ...

  7. The magnitude of the effect of calf muscles fatigue on postural control during bipedal quiet standing with vision depends on the eye-visual target distance.

    Vuillerme, Nicolas; Burdet, Cyril; Isableu, Brice; Demetz, Sylvain

    2006-01-01

    The purpose of the present experiment was to investigate whether, with vision, the magnitude of the effect of calf muscles fatigue on postural control during bipedal quiet standing depends on the eye-visual target distance. Twelve young university students were asked to stand upright as immobile as possible in three visual conditions (No vision, Vision 1m and Vision 4m) executed in two conditions of No fatigue and Fatigue of the calf muscles. Centre of foot pressure displacements were recorde...

  8. Ultrasound-Derived Abdominal Muscle Thickness Better Detects Metabolic Syndrome Risk in Obese Patients than Skeletal Muscle Index Measured by Dual-Energy X-Ray Absorptiometry.

    Ayumi Ido

    Full Text Available Sarcopenia has never been diagnosed based on site-specific muscle loss, and little is known about the relationship between site-specific muscle loss and metabolic syndrome (MetS risk factors. To this end, this cross-sectional study aimed to investigate the relationship between site-specific muscle size and MetS risk factors. Subjects were 38 obese men and women aged 40-82 years. Total body fat and lean body mass were assessed by whole-body dual-energy X-ray absorptiometry (DXA scan. Muscle thickness (MTH was measured using B-mode ultrasound scanning in six body regions. Subjects were classified into general obesity (GO and sarcopenic obesity (SO groups using the threshold values of one standard deviation below the sex-specific means of either MTH or skeletal muscle index (SMI measured by DXA. MetS risk score was acquired by standardizing and summing the following continuously distributed variables: visceral fat area, mean blood pressure, HbA1c, and serum triglyceride / high density lipoprotein cholesterol, to obtain the Z-score. Multiple regression analysis revealed that the MetS risk score was independently associated with abdominal MTH in all subjects, but not with MTH in other muscle regions, including the thigh. Although HbA1c and the number of MetS risk factors in the SO group were significantly higher than those in the GO group, there were no significant differences between GO and SO groups as defined by SMI. Ultrasound-derived abdominal MTH would allow a better assessment of sarcopenia in obese patients and can be used as an alternative to the conventionally-used SMI measured by DXA.

  9. Ultrasound-Derived Abdominal Muscle Thickness Better Detects Metabolic Syndrome Risk in Obese Patients than Skeletal Muscle Index Measured by Dual-Energy X-Ray Absorptiometry.

    Ido, Ayumi; Nakayama, Yuki; Ishii, Kojiro; Iemitsu, Motoyuki; Sato, Koji; Fujimoto, Masahiro; Kurihara, Toshiyuki; Hamaoka, Takafumi; Satoh-Asahara, Noriko; Sanada, Kiyoshi

    2015-01-01

    Sarcopenia has never been diagnosed based on site-specific muscle loss, and little is known about the relationship between site-specific muscle loss and metabolic syndrome (MetS) risk factors. To this end, this cross-sectional study aimed to investigate the relationship between site-specific muscle size and MetS risk factors. Subjects were 38 obese men and women aged 40-82 years. Total body fat and lean body mass were assessed by whole-body dual-energy X-ray absorptiometry (DXA) scan. Muscle thickness (MTH) was measured using B-mode ultrasound scanning in six body regions. Subjects were classified into general obesity (GO) and sarcopenic obesity (SO) groups using the threshold values of one standard deviation below the sex-specific means of either MTH or skeletal muscle index (SMI) measured by DXA. MetS risk score was acquired by standardizing and summing the following continuously distributed variables: visceral fat area, mean blood pressure, HbA1c, and serum triglyceride / high density lipoprotein cholesterol, to obtain the Z-score. Multiple regression analysis revealed that the MetS risk score was independently associated with abdominal MTH in all subjects, but not with MTH in other muscle regions, including the thigh. Although HbA1c and the number of MetS risk factors in the SO group were significantly higher than those in the GO group, there were no significant differences between GO and SO groups as defined by SMI. Ultrasound-derived abdominal MTH would allow a better assessment of sarcopenia in obese patients and can be used as an alternative to the conventionally-used SMI measured by DXA. PMID:26700167

  10. Incubating isolated mouse EDL muscles with creatine improves force production and twitch kinetics in fatigue due to reduction in ionic strength.

    Stewart I Head

    Full Text Available BACKGROUND: Creatine supplementation can improve performance during high intensity exercise in humans and improve muscle strength in certain myopathies. In this present study, we investigated the direct effects of acute creatine incubation on isolated mouse fast-twitch EDL muscles, and examined how these effects change with fatigue. METHODS AND RESULTS: The extensor digitorum longus muscle from mice aged 12-14 weeks was isolated and stimulated with field electrodes to measure force characteristics in 3 different states: (i before fatigue; (ii immediately after a fatigue protocol; and (iii after recovery. These served as the control measurements for the muscle. The muscle was then incubated in a creatine solution and washed. The measurement of force characteristics in the 3 different states was then repeated. In un-fatigued muscle, creatine incubation increased the maximal tetanic force. In fatigued muscle, creatine treatment increased the force produced at all frequencies of stimulation. Incubation also increased the rate of twitch relaxation and twitch contraction in fatigued muscle. During repetitive fatiguing stimulation, creatine-treated muscles took 55.1±9.5% longer than control muscles to lose half of their original force. Measurement of weight changes showed that creatine incubation increased EDL muscle mass by 7%. CONCLUSION: Acute creatine application improves force production in isolated fast-twitch EDL muscle, and these improvements are particularly apparent when the muscle is fatigued. One likely mechanism for this improvement is an increase in Ca(2+ sensitivity of contractile proteins as a result of ionic strength decreases following creatine incubation.

  11. A study of fatigue in rabbit skeletal muscle by in vivo 31P MRS

    Energy metabolism during exercise and recovery process of rabbit skeletal muscle was obserbed by in vivo 31P MRS. The small value of the ratio of the intensities between inorganic phosphate and phosphocreatine at rest indicated that the observed moiety of muscle had high fast-twitch fiber content. More than half of ATP and almost all of phosphocreatine were depleted by electric stimulation at 4Hz. The extreme intracellular pH was 5.9. The recovery from this metabolic state was very slow, and only a small amount of ATP was resynthesized after 40 minutes of recovery. These phenomena show the characteristic features of the energy metabolism in the fatigue of fast-twitch muscle. The metabolic state as indicated by the intensity of phosphocreatine and intracellular pH during exercise was not always parallel to contraction power measured by straingauge. Two inorganic phosphate peaks were observed, which are regarded as the signals from fast-twitch fiber and slow-twitch fiber from their pH values. The ratios of these two peaks were different between 1Hz, 2Hz, and 4Hz electric stimulation. We conclude that we are observing the different recruitment of fiber types at different exercise level in vivo. (author)

  12. The Effectiveness of FES-Evoked EMG Potentials to Assess Muscle Force and Fatigue in Individuals with Spinal Cord Injury

    Morufu Olusola Ibitoye

    2014-07-01

    Full Text Available The evoked electromyographic signal (eEMG potential is the standard index used to monitor both electrical changes within the motor unit during muscular activity and the electrical patterns during evoked contraction. However, technical and physiological limitations often preclude the acquisition and analysis of the signal especially during functional electrical stimulation (FES-evoked contractions. Hence, an accurate quantification of the relationship between the eEMG potential and FES-evoked muscle response remains elusive and continues to attract the attention of researchers due to its potential application in the fields of biomechanics, muscle physiology, and rehabilitation science. We conducted a systematic review to examine the effectiveness of eEMG potentials to assess muscle force and fatigue, particularly as a biofeedback descriptor of FES-evoked contractions in individuals with spinal cord injury. At the outset, 2867 citations were identified and, finally, fifty-nine trials met the inclusion criteria. Four hypotheses were proposed and evaluated to inform this review. The results showed that eEMG is effective at quantifying muscle force and fatigue during isometric contraction, but may not be effective during dynamic contractions including cycling and stepping. Positive correlation of up to r = 0.90 (p < 0.05 between the decline in the peak-to-peak amplitude of the eEMG and the decline in the force output during fatiguing isometric contractions has been reported. In the available prediction models, the performance index of the eEMG signal to estimate the generated muscle force ranged from 3.8% to 34% for 18 s to 70 s ahead of the actual muscle force generation. The strength and inherent limitations of the eEMG signal to assess muscle force and fatigue were evident from our findings with implications in clinical management of spinal cord injury (SCI population.

  13. Associations between low back pain, urinary incontinence, and abdominal muscle recruitment as assessed via ultrasonography in the elderly

    Vânia F. Figueiredo

    2015-02-01

    Full Text Available Background: Low back pain (LBP and urinary incontinence (UI are highly prevalent among elderly individuals. In young adults, changes in trunk muscle recruitment, as assessed via ultrasound imaging, may be associated with lumbar spine stability. Objective: To assess the associations between LBP, UI, and the pattern of transversus abdominis (TrA, internal (IO, and external oblique (EO muscle recruitment in the elderly as evaluated by ultrasound imaging. Method: Fifty-four elderly individuals (mean age: 72±5.2 years who complained of LBP and/or UI as assessed by the McGill Pain Questionnaire, Incontinence Questionnaire-Short Form, and ultrasound imaging were included in the study. The statistical analysis comprised a multiple linear regression model, and a p-value <0.05 was considered significant. Results: The regression models for the TrA, IO, and EO muscle thickness levels explained 2.0% (R2=0.02; F=0.47; p=0.628, 10.6% (R2=0.106; F=3.03; p=0.057, and 10.1% (R2=0.101; F=2.70; p=0.077 of the variability, respectively. None of the regression models developed for the abdominal muscles exhibited statistical significance. A significant and negative association (p=0.018; β=-0.0343 was observed only between UI and IO recruitment. Conclusion: These results suggest that age-related factors may have interfered with the findings of the study, thus emphasizing the need to perform ultrasound imaging-based studies to measure abdominal muscle recruitment in the elderly.

  14. Associations between low back pain, urinary incontinence, and abdominal muscle recruitment as assessed via ultrasonography in the elderly

    Figueiredo, Vânia F.; Amorim, Juleimar S. C.; Pereira, Aline M.; Ferreira, Paulo H.; Pereira, Leani S. M.

    2015-01-01

    Background: Low back pain (LBP) and urinary incontinence (UI) are highly prevalent among elderly individuals. In young adults, changes in trunk muscle recruitment, as assessed via ultrasound imaging, may be associated with lumbar spine stability. Objective: To assess the associations between LBP, UI, and the pattern of transversus abdominis (TrA), internal (IO), and external oblique (EO) muscle recruitment in the elderly as evaluated by ultrasound imaging. Method: Fifty-four elderly individuals (mean age: 72±5.2 years) who complained of LBP and/or UI as assessed by the McGill Pain Questionnaire, Incontinence Questionnaire-Short Form, and ultrasound imaging were included in the study. The statistical analysis comprised a multiple linear regression model, and a p-value <0.05 was considered significant. Results: The regression models for the TrA, IO, and EO muscle thickness levels explained 2.0% (R2=0.02; F=0.47; p=0.628), 10.6% (R2=0.106; F=3.03; p=0.057), and 10.1% (R2=0.101; F=2.70; p=0.077) of the variability, respectively. None of the regression models developed for the abdominal muscles exhibited statistical significance. A significant and negative association (p=0.018; β=-0.0343) was observed only between UI and IO recruitment. Conclusion: These results suggest that age-related factors may have interfered with the findings of the study, thus emphasizing the need to perform ultrasound imaging-based studies to measure abdominal muscle recruitment in the elderly. PMID:25714438

  15. Correlation between vitamin D levels and muscle fatigue risk factors based on physical activity in healthy older adults

    Al-Eisa ES

    2016-05-01

    Full Text Available Einas S Al-Eisa,1 Ahmad H Alghadir,1 Sami A Gabr1,2 1Rehabilitation Research Chair, College of Applied Medical Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia; 2Department of Anatomy, Faculty of Medicine, Mansoura University, Mansoura, Egypt Purpose: The purpose of this study was to investigate the relationship of serum vitamin D levels with physical activity, obesity, muscle fatigue biomarkers, and total antioxidant capacity (TAC in healthy older adults.Methods: A total of 85 healthy older subjects aged 64–96 years were recruited in this study. Based on estimated energy expenditure scores, the participants were classified into three groups: inactive (n=25, moderate (n=20, and physically active (n=35. Serum 25(OHD (25-hydroxy vitamin D levels, metabolic syndrome parameters, TAC activity, muscle fatigue biomarkers (Ca, creatine kinase, lactic acid dehydrogenase, troponin I, hydroxyproline, physical activity, body fatness, and fatigue score (visual analog scale were estimated using immunoassay techniques and prevalidated questionnaires, respectively.Results: Physical activity was estimated in 64.6% of the participants. Males showed higher physical activity (42.5% compared to females (26.25%. Compared to participants with lower activity, significant reduction in body mass index, waist circumference, hips, fasting blood sugar, triglycerides, total cholesterol, HDL-cholesterol, and LDL-cholesterol were observed in moderate and physically active participants. Also, significant increase in the levels of serum 25(OHD concentrations, calcium, and TAC activity along with reduction in the levels of muscle fatigue biomarkers: creatine kinase, lactic acid dehydrogenase, troponin I, hydroxyproline, and fatigue scores (visual analog scale were reported in physically active participants compared to those of lower physical activity. In all participants, serum 25(OHD concentrations correlated positively with Ca, TAC, physical activity scores

  16. Fatigue

    ... organs. Your body also changes the way it processes foods and nutrients. All of these changes are stressful for your body and may lead to fatigue. Physical and psychological changes during pregnancy can also cause mental and emotional stress. This stress can add to your feelings ...

  17. Development of Activity-Related Muscle Fatigue during Robot-Mediated Upper Limb Rehabilitation Training in Persons with Multiple Sclerosis: A Pilot Trial

    2015-01-01

    Robot-assisted rehabilitation facilitates high-intensity training of the impaired upper limb in neurological rehabilitation. It has been clinically observed that persons with Multiple Sclerosis (MS) have difficulties in sustaining the training intensity during a session due to the development of activity-related muscle fatigue. An experimental observational pilot study was conducted to examine whether or not the muscle fatigue develops in MS patients during one session of robot-assisted training within a virtual learning environment. Six MS patients with upper limb impairment (motricity index ranging from 50 to 91/100) and six healthy persons completed five training bouts of three minutes each performing lifting tasks, while EMG signals of anterior deltoid and lower trapezius muscles were measured and their subjective perceptions on muscle fatigue were registered. Decreased performance and higher subjective fatigue perception were present in the MS group. Increased mean EMG amplitudes and subjective perception levels on muscle fatigue were observed in both groups. Muscle fatigue development during 15′ training has been demonstrated in the arm of MS patients, which influences the sustainability of training intensity in MS patients. To optimize the training performance, adaptivity based on the detection of MS patient's muscle fatigue could be provided by means of training program adjustment. PMID:26090229

  18. Development of Activity-Related Muscle Fatigue during Robot-Mediated Upper Limb Rehabilitation Training in Persons with Multiple Sclerosis: A Pilot Trial

    Johanna Renny Octavia

    2015-01-01

    Full Text Available Robot-assisted rehabilitation facilitates high-intensity training of the impaired upper limb in neurological rehabilitation. It has been clinically observed that persons with Multiple Sclerosis (MS have difficulties in sustaining the training intensity during a session due to the development of activity-related muscle fatigue. An experimental observational pilot study was conducted to examine whether or not the muscle fatigue develops in MS patients during one session of robot-assisted training within a virtual learning environment. Six MS patients with upper limb impairment (motricity index ranging from 50 to 91/100 and six healthy persons completed five training bouts of three minutes each performing lifting tasks, while EMG signals of anterior deltoid and lower trapezius muscles were measured and their subjective perceptions on muscle fatigue were registered. Decreased performance and higher subjective fatigue perception were present in the MS group. Increased mean EMG amplitudes and subjective perception levels on muscle fatigue were observed in both groups. Muscle fatigue development during 15′ training has been demonstrated in the arm of MS patients, which influences the sustainability of training intensity in MS patients. To optimize the training performance, adaptivity based on the detection of MS patient’s muscle fatigue could be provided by means of training program adjustment.

  19. MANAGING FATIGUE IN SPORTS

    2006-01-01

    @@ Fatigue is a multifactorial process. Depletion of energy sources, including adenosine triphosphate (ATP), phosphocreatine (PCr), plus carbohydrates (CHO) like muscle glycogen and blood glucose can contribute to fatigue.

  20. Evoked EMG versus Muscle Torque during Fatiguing Functional Electrical Stimulation-Evoked Muscle Contractions and Short-Term Recovery in Individuals with Spinal Cord Injury

    Eduardo H. Estigoni

    2014-12-01

    Full Text Available This study investigated whether the relationship between muscle torque and m-waves remained constant after short recovery periods, between repeated intervals of isometric muscle contractions induced by functional electrical stimulation (FES. Eight subjects with spinal cord injury (SCI were recruited for the study. All subjects had their quadriceps muscles group stimulated during three sessions of isometric contractions separated by 5 min of recovery. The evoked-electromyographic (eEMG signals, as well as the produced torque, were synchronously acquired during the contractions and during short FES bursts applied during the recovery intervals. All analysed m-wave variables changed progressively throughout the three contractions, even though the same muscle torque was generated. The peak to peak amplitude (PtpA, and the m-wave area (Area were significantly increased, while the time between the stimulus artefact and the positive peak (PosT were substantially reduced when the muscles became fatigued. In addition, all m-wave variables recovered faster and to a greater extent than did torque after the recovery intervals. We concluded that rapid recovery intervals between FES-evoked exercise sessions can radically interfere in the use of m-waves as a proxy for torque estimation in individuals with SCI. This needs to be further investigated, in addition to seeking a better understanding of the mechanisms of muscle fatigue and recovery.

  1. Near-infrared monitoring of perfusion and oxygen availability in abdominal organs and skeletal muscle during hypoxia

    Maarek, Jean-Michel I.; Vari, Sandor G.; Marcu, Laura; Papaioannou, Thanassis; Pergadia, Vani R.; Snyder, Wendy J.; Grundfest, Warren S.

    1994-05-01

    Near-IR spectroscopy was used to quantify blood content and oxygenation dynamics in abdominal organs and skeletal muscle of 18 anesthetized rabbits during hypoxic hypoxia. Liver, kidney, and hindlimb muscle were exposed surgically. Laser diode pulses transmitted across the tissues were detected by means of a photomultiplier. The amount and redox level of tissue hemoglobin were estimated from the near-IR signals and monitored during 5- min-long hypoxic challenges and subsequent recovery periods. In the kidney, exposure to 10% FiO2 resulted in rapid and symmetrical changes in oxygenated and reduced hemoglobin with 50% of the variations occurring within 1 min and a plateau after 3 min. Total hemoglobin did not change and hemoglobin oxygenation returned to baseline within 1 min of hypoxia cessation. Exposure to 6% FiO2 doubled the decrease in oxygenated hemoglobin and induced a sustained vasoconstriction which decreased total hemoglobin content 2 min after initiation of hypoxia. Comparable patterns were observed in the liver and skeletal muscle with the following exceptions: local vasoconstriction was generally not observed at 6% FiO2, return to baseline oxygen availability was much slower in skeletal muscle than in the other organs.

  2. An investigation of the reproducibility of ultrasound measures of abdominal muscle activation in patients with chronic non-specific low back pain

    Costa, Leonardo Oliveira Pena; Maher, Chris G.; Latimer, Jane; Hodges, Paul W.; Shirley, Debra

    2009-01-01

    Ultrasound (US) measures are used by clinicians and researchers to evaluate improvements in activity of the abdominal muscles in patients with low back pain. Studies evaluating the reproducibility of these US measures provide some information; however, little is known about the reproducibility of these US measures over time in patients with low back pain. The objectives of this study were to estimate the reproducibility of ultrasound measurements of automatic activation of the lateral abdomin...

  3. Loss of abdominal muscle in Pitx2 mutants associated with altered axial specification of lateral plate mesoderm.

    Diana Eng

    Full Text Available Sequence specific transcription factors (SSTFs combinatorially define cell types during development by forming recursively linked network kernels. Pitx2 expression begins during gastrulation, together with Hox genes, and becomes localized to the abdominal lateral plate mesoderm (LPM before the onset of myogenesis in somites. The somatopleure of Pitx2 null embryos begins to grow abnormally outward before muscle regulatory factors (MRFs or Pitx2 begin expression in the dermomyotome/myotome. Abdominal somites become deformed and stunted as they elongate into the mutant body wall, but maintain normal MRF expression domains. Subsequent loss of abdominal muscles is therefore not due to defects in specification, determination, or commitment of the myogenic lineage. Microarray analysis was used to identify SSTF families whose expression levels change in E10.5 interlimb body wall biopsies. All Hox9-11 paralogs had lower RNA levels in mutants, whereas genes expressed selectively in the hypaxial dermomyotome/myotome and sclerotome had higher RNA levels in mutants. In situ hybridization analyses indicate that Hox gene expression was reduced in parts of the LPM and intermediate mesoderm of mutants. Chromatin occupancy studies conducted on E10.5 interlimb body wall biopsies showed that Pitx2 protein occupied chromatin sites containing conserved bicoid core motifs in the vicinity of Hox 9-11 and MRF genes. Taken together, the data indicate that Pitx2 protein in LPM cells acts, presumably in combination with other SSTFs, to repress gene expression, that are normally expressed in physically adjoining cell types. Pitx2 thereby prevents cells in the interlimb LPM from adopting the stable network kernels that define sclerotomal, dermomyotomal, or myotomal mesenchymal cell types. This mechanism may be viewed either as lineage restriction or specification.

  4. The slow component of pulmonary O2 uptake accompanies peripheral muscle fatigue during high-intensity exercise.

    Keir, Daniel A; Copithorne, David B; Hodgson, Michael D; Pogliaghi, Silvia; Rice, Charles L; Kowalchuk, John M

    2016-08-01

    During constant-power output (PO) exercise above lactate threshold (LT), pulmonary O2 uptake (V̇o2 p) features a developing slow component (V̇o2 pSC). This progressive increase in O2 cost of exercise is suggested to be related to the effects of muscle fatigue development. We hypothesized that peripheral muscle fatigue as assessed by contractile impairment would be associated with the V̇o2 pSC Eleven healthy men were recruited to perform four constant-PO tests at an intensity corresponding to ∼Δ60 (very heavy, VH) where Δ is 60% of the difference between LT and peak V̇o2 p The VH exercise was completed for each of 3, 8, 13, and 18 min (i.e., VH3, VH8, VH13, VH18) with each preceded by 3 min of cycling at 20 W. Peripheral muscle fatigue was assessed via pre- vs. postexercise measurements of quadriceps torque in response to brief trains of electrical stimulation delivered at low (10 Hz) and high (50 Hz) frequencies. During exercise, breath-by-breath V̇o2 p was measured by mass spectrometry and volume turbine. The magnitude of V̇o2 pSC increased (P loss of muscle efficiency. PMID:27339183

  5. The role of computed tomography in evaluating body composition and the influence of reduced muscle mass on clinical outcome in abdominal malignancy: a systematic review.

    Gibson, D J; Burden, S T; Strauss, B J; Todd, C; Lal, S

    2015-10-01

    It is estimated that there were 3.45 million new cases and 1.75 million deaths from cancer in Europe in 2012. Colorectal cancer was one of the most common cancers, accounting for 13% of new cases and 12.2% of all deaths. Conditions causing reduced muscle mass, such as sarcopenia, can increase the morbidity and mortality of people with cancer. Computed tomography (CT) scans can provide accurate, high-quality information on body composition, including muscle mass. To date, there has been no systematic review on the role of CT scans in identifying sarcopenia in abdominal cancer. This review aimed to examine the role of CT scans in determining the influence of reduced muscle mass on clinical outcome in abdominal cancer. A systematic review of English-language articles published in 2000 or later was conducted. Articles included cohort, randomised controlled trials and validation studies. Participants were people diagnosed with abdominal cancer who had undergone a CT scan. Data extraction and critical appraisal were undertaken. Ten cohort studies met the inclusion criteria. Seven studies demonstrated that low muscle mass was significantly associated with poor clinical outcome, with six specifically demonstrating reduced survival rates. Eight studies demonstrated that a greater number of patients (27.3-66.7%) were identified as sarcopenic using CT scans compared with numbers identified as malnourished using body mass index. CT scans can identify reduced muscle mass and predict negative cancer outcomes in people with abdominal malignancies, where traditional methods of assessment are less effective. PMID:25782424

  6. Development of Activity-Related Muscle Fatigue during Robot-Mediated Upper Limb Rehabilitation Training in Persons with Multiple Sclerosis: A Pilot Trial

    Johanna Renny Octavia; Peter Feys; Karin Coninx

    2015-01-01

    Robot-assisted rehabilitation facilitates high-intensity training of the impaired upper limb in neurological rehabilitation. It has been clinically observed that persons with Multiple Sclerosis (MS) have difficulties in sustaining the training intensity during a session due to the development of activity-related muscle fatigue. An experimental observational pilot study was conducted to examine whether or not the muscle fatigue develops in MS patients during one session of robot-assisted train...

  7. Deer Antler Extract Improves Fatigue Effect through Altering the Expression of Genes Related to Muscle Strength in Skeletal Muscle of Mice

    Jaw-Chyun Chen

    2014-01-01

    Full Text Available Deer antler is a well-known traditional Chinese medicine used in Asian countries for the tonic and the improvement of aging symptoms. The present study was designed to investigate the antifatigue effect and mechanism of Formosan sambar deer tip antler extract (FSDTAE. The swimming times to exhaustion of mice administered FSDTAE (8.2 mg/day for 28 days were apparently longer than those of the vehicle-treated mice in forced swim test. However, the indicators of fatigue, such as the reduction in glucose level and the increases in blood urea nitrogen and lactic acid levels, were not significantly inhibited by FSDTAE. Therefore, microarray analysis was further used to examine the anti-fatigue mechanism of FSDTAE. We selected genes with fold changes >2 or <−2 in skeletal muscle for pathway analysis. FSDTAE-affected genes were involved in 9 different signaling pathways, such as GnRH signaling pathway and insulin signaling pathway. All of the significantly expressed genes were classified into 8 different categories by their functions. The most enriched category was muscular system, and 6 upregulated genes, such as troponin I, troponin T1, cysteine and glycine-rich protein 2, myosin heavy polypeptide 7, tropomyosin 2, and myomesin family member 3, were responsible for the development and contraction of muscle. Real-time PCR analysis indicated that FSDTAE increased troponins mRNA expression in skeletal muscle. In conclusion, our findings suggested that FSDTAE might increase the muscle strength through the upregulation of genes responsible for muscle contraction and consequently exhibited the anti-fatigue effect in mice.

  8. Kinesiology Tape or Compression Sleeve Applied to the Thigh Does Not Improve Balance or Muscle Activation Before or Following Fatigue.

    Cavanaugh, M Tyler; Quigley, Patrick J; Hodgson, Daniel D; Reid, Jonathan C; Behm, David G

    2016-07-01

    Cavanaugh, MT, Quigley, PJ, Hodgson, DD, Reid, JC, and Behm, DG. Kinesiology tape or compression sleeve applied to the thigh does not improve balance or muscle activation before or following fatigue. J Strength Cond Res 30(7): 1992-2000, 2016-Compression sleeves (CS) and kinesiology tape (KT) are purported to enhance proprioception, however, there is substantial conflict in the literature. Because the beneficial effects of CS and KT are more evident in the literature with recovery, the objective of this study was to examine the effects of CS and KT on balance under acute nonfatigued and postfatigued conditions. Using a within-subject, repeated-measures design, 12 university participants (5 females and 7 males) performed in a random order CS, KT, and Control conditions. Two trials of each test were conducted before the application of CS or KT (pretest 1), immediately after the application (pretest 2), with posttests at 1 and 10 minutes after 4 sets of unilateral Bulgarian squats to failure (1 minute rest between sets). Tests included a Y balance test (measures: distance reached by nondominant foot in anterior, posterior lateral, and posterior medial directions) and drop jump landing balance test from a 50-cm platform (measures: ground reaction force, electromyography, and center of pressure). The fatigue protocol induced 25.3% decrease in unilateral squat repetitions from set 1 to set 4. There were no significant condition main effects or interactions for any balance measure or EMG before or after fatigue. In conclusion, independent of fatigue, there was no significant effect of CS or KT on balance outcomes immediately and up to 10 minutes following the fatiguing intervention. Thus, nonfatigued or muscles weakened by fatigue did not benefit from CS and KT application. PMID:26705066

  9. Correlation between vitamin D levels and muscle fatigue risk factors based on physical activity in healthy older adults

    Al-Eisa ES; Alghadir AH; Gabr SA

    2016-01-01

    Einas S Al-Eisa,1 Ahmad H Alghadir,1 Sami A Gabr1,2 1Rehabilitation Research Chair, College of Applied Medical Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia; 2Department of Anatomy, Faculty of Medicine, Mansoura University, Mansoura, Egypt Purpose: The purpose of this study was to investigate the relationship of serum vitamin D levels with physical activity, obesity, muscle fatigue biomarkers, and total antioxidant capacity (TAC) in healthy older adults.Methods: A total of...

  10. A Comparison of Flexi-bar and General Lumbar Stabilizing Exercise Effects on Muscle Activity and Fatigue

    Kim, Jung-Hee; So, Ki-Hyun; Bae, Yu-Ri; Lee, Byoung-Hee

    2014-01-01

    [Purpose] The objective of this study was to compare the effects of flexi-bar training and general lumbar stabilization training on muscle activity and fatigue. [Methods] Twenty normal persons participated in this study. After warm up and a Maximum Voluntary Isomeric Contraction (MVIC) test, participants performed bridging exercise, quadruped lumbar stabilization exercise on quadruped and curl-up, with and without the flexi-bar training, each exercise lasting for 30 seconds. Electromyography ...

  11. A narrative review of exercise-associated muscle cramps: Factors that contribute to neuromuscular fatigue and management implications.

    Nelson, Nicole L; Churilla, James R

    2016-08-01

    Although exercise-associated muscle cramps (EAMC) are highly prevalent among athletic populations, the etiology and most effective management strategies are still unclear. The aims of this narrative review are 3-fold: (1) briefly summarize the evidence regarding EAMC etiology; (2) describe the risk factors and possible physiological mechanisms associated with neuromuscular fatigue and EAMC; and (3) report the current evidence regarding prevention of, and treatment for, EAMC. Based on the findings of several large prospective and experimental investigations, the available evidence indicates that EAMC is multifactorial in nature and stems from an imbalance between excitatory drive from muscle spindles and inhibitory drive from Golgi tendon organs to the alpha motor neurons rather than dehydration or electrolyte deficits. This imbalance is believed to stem from neuromuscular overload and fatigue. In concert with these findings, the most successful treatment for an acute bout of EAMC is stretching, whereas auspicious methods of prevention include efforts that delay exercise-induced fatigue. Muscle Nerve 54: 177-185, 2016. PMID:27159592

  12. Progressive Muscle Relaxation: An adjuvant therapy for reducing pain and fatigue among hospitalized cancer patients’ receiving radiotherapy.

    Pragya Pathak

    2013-03-01

    Full Text Available Background: Cancer patients’ face number of problems, among those pain and fatigue are common problems. To manage pain and fatigue among cancer patients, studies now a days are even focusing on use of non-pharmacological/ non invasive methods as exercises, imagery etc. But studies on effect of progressive muscle relaxation (PMR exercises on pain and fatigue among admitted patients are scarce. Objective: The study was done to evaluate effectiveness of PMR exercises on pain and fatigue among hospitalized cancer patients’ receiving radiotherapy. Methods: The study design was quasi-experimental Pre test Post test control group design. Total of 100 participants, 50 in each intervention and control group were included. The subjects in the intervention group received four PMR exercise sessions in 4weeks along with routine standardized treatment while subjects in control group received treatment as usual with no added intervention. Results: There was significant difference (p<0.01 in Pre NPRS (4.42±2.35 to post NPRS (3.44±2.05 scores among intervention group (PMR. Pre assessment mean fatigue scores (CFS of subjects were 33.80±10.62 in intervention group (PMR and 33.24±7.02 in controls where as post assessment CFS were 28.52±12.74 and 36.52±7.53 in intervention and control group respectively. There was significant (p<0.01 reduction in pre to post CFS in PMR group while fatigue increased significantly (p<0.01 in control group. Conclusion: PMR along with routine standard treatment is effective in reducing pain and fatigue among hospitalized cancer patients receiving radiotherapy.

  13. Postoperative outcomes following preoperative inspiratory muscle training in patients undergoing open cardiothoracic or upper abdominal surgery: protocol for a systematic review

    Mans Christina M

    2012-12-01

    Full Text Available Abstract Background In patients undergoing open cardiothoracic and upper abdominal surgery, postoperative pulmonary complications remain an important cause of postoperative morbidity and mortality, impacting upon hospital length of stay and health care resources. Adequate preoperative respiratory muscle strength may help protect against the development of postoperative pulmonary complications and therefore preoperative inspiratory muscle training has been suggested to be of potential value in improving postoperative outcomes. Methods/Design A systematic search of electronic databases will be undertaken to identify randomized trials of preoperative inspiratory muscle training in patients undergoing elective open cardiothoracic and upper abdominal surgery. From these trials, we will extract available data for a list of predefined outcomes, including postoperative pulmonary complications, hospital length of stay and respiratory muscle strength. We will meta-analyze comparable results where possible, and report a summary of the available pool of evidence. Discussion This review will provide the most comprehensive answer available to the question of whether preoperative inspiratory muscle training is clinically useful in improving postoperative outcomes in patients undergoing cardiothoracic and upper abdominal surgery. It will help inform clinicians working in the surgical arena of the likely effectiveness of instituting preoperative inspiratory muscle training programs to improve postoperative outcomes.

  14. Comparison of the effect of alpha1- and alpha2-adrenoceptor agonists and antagonists on muscle contractility of the rabbit abdominal aorta in vitro.

    Gnus, Jan; Rusiecka, Agnieszka; Czerski, Albert; Zawadzki, Wojciech; Witkiewicz, Wojciech; Hauzer, Willy

    2013-01-01

    The aim of the study was to demonstrate the effect of selected agonists and antagonists of alpha-adrenergic receptors on muscle contractility of the rabbit abdominal aorta in vitro with particular emphasis on alpha2-adrenergic receptor subtypes. The study was conducted on 30 New Zealand breed rabbits from which specimens of the abdominal aorta were collected. The sections were set up in an automatic water bath in a Krebs-Henseleit buffer at 37 degrees C. The experiments showed that alpha1-adrenergic receptors played the main role in the contractile response ofthe rabbit abdominal aorta. Stimulation of alpha1-adrenergic receptor by administration ofphenylephrine resulted in an increase in smooth muscle tonus ofthe rabbit abdominal aorta by an average of 4.75 mN. The reaction after stimulation of alpha2-adrenergic receptors by similar doses of their agonists was much weaker. Prolonged tissue response time and time needed to reach maximum tonus for alpha2-adrenergic receptor agonists were observed. The obtained results confirm the thesis that the alpha1-adrenergic receptor is the most important factor controlling the contractility of the rabbit abdominal aorta, but the alpha2-adrenergic receptor is also involved in maintaining muscle tissue tonus. PMID:23767297

  15. Muscle Fatigue in the Three Heads of the Triceps Brachii During a Controlled Forceful Hand Grip Task with Full Elbow Extension Using Surface Electromyography

    Ali, Asraf; Sundaraj, Kenneth; Badlishah Ahmad, R.; Ahamed, Nizam Uddin; Islam, Anamul; Sundaraj, Sebastian

    2015-01-01

    The objective of the present study was to investigate the time to fatigue and compare the fatiguing condition among the three heads of the triceps brachii muscle using surface electromyography during an isometric contraction of a controlled forceful hand grip task with full elbow extension. Eighteen healthy subjects concurrently performed a single 90 s isometric contraction of a controlled forceful hand grip task and full elbow extension. Surface electromyographic signals from the lateral, long and medial heads of the triceps brachii muscle were recorded during the task for each subject. The changes in muscle activity among the three heads of triceps brachii were measured by the root mean square values for every 5 s period throughout the total contraction period. The root mean square values were then analysed to determine the fatiguing condition for the heads of triceps brachii muscle. Muscle fatigue in the long, lateral, and medial heads of the triceps brachii started at 40 s, 50 s, and 65 s during the prolonged contraction, respectively. The highest fatiguing rate was observed in the long head (slope = −2.863), followed by the medial head (slope = −2.412) and the lateral head (slope = −1.877) of the triceps brachii muscle. The results of the present study concurs with previous findings that the three heads of the triceps brachii muscle do not work as a single unit, and the fiber type/composition is different among the three heads. PMID:26240650

  16. Respiratory responses to stimulation of abdominal and upper-thorax intercostal muscles using multiple Permaloc® electrodes

    James S. Walter, PhD

    2015-04-01

    Full Text Available Stimulation of abdominal and upper-thoracic muscles was studied with the long-term goal of improved respiratory care for spinal cord injury (SCI patients. A 12-channel stimulator and multiple surface and implanted Permaloc electrodes were evaluated in five anesthetized canines. Abdominal stimulation with 100 mA using four bilateral sets of surface electrodes placed on the midaxillary line at the 7th through 13th intercostal spaces and with a closed airway at a large lung volume produced an expiratory tracheal pressure of 109 +/– 29 cm H2O (n = 2, mean +/– standard error of the mean. Similar high pressures were induced with implanted electrodes at the same locations. Upper-thoracic stimulation with 40 mA and four sets of implanted electrodes ventral to the axilla induced inspiratory pressures of −12 +/– 2 cm H2O (n = 5. Combined extradiaphragmatic pacing with an open airway produced a tidal volume of 440 +/– 45 mL (n = 4. The robust respiratory volumes and pressures suggest applications in SCI respiratory care.

  17. Effects of diaphragm stretching on posterior chain muscle kinematics and rib cage and abdominal excursion: a randomized controlled trial

    Francisco J. González-Álvarez

    2016-01-01

    Full Text Available ABSTRACT Background Few studies have explored the effects of stretching techniques on diaphragm and spine kinematics. Objective To determine whether the application of diaphragm stretching resulted in changes in posterior chain muscle kinematics and ribcage and abdominal excursion in healthy subjects. Method Eighty healthy adults were included in this randomized clinical trial. Participants were randomized into two groups: the experimental group, which received a diaphragmatic stretching technique, or the placebo group, which received a sham-ultrasound procedure. The duration of the technique, the position of participants, and the therapist who applied the technique were the same for both treatments. Participant assessment (cervical range of movement, lumbar flexibility, flexibility of the posterior chain, and rib cage and abdominal excursion was performed at baseline and immediately after the intervention by a blinded assessor. Results The mean between-group difference [95% CI] for the ribcage excursion after technique at xiphoid level was 2.48 [0.97 to 3.99], which shows significant differences in this outcome. The remaining between-group analysis showed significant differences in cervical extension, right and left flexion, flexibility of the posterior chain, and ribcage excursion at xiphoid level (p<0.05 in favor of the experimental group. Conclusion Diaphragm stretching generates a significant improvement in cervical extension, right and left cervical flexion, flexibility of the posterior chain, and ribcage excursion at xiphoid level compared to a placebo technique in healthy adults.

  18. Measuring abdominal circumference and skeletal muscle from a single cross-sectional CT image: a step-by-step guide for clinicians using National Institutes of Health ImageJ

    Gomez-Perez, Sandra L.; Haus, Jacob M.; Sheean, Patricia; Patel, Bimal; Mar, Winnie; Chaudhry, Vivek; McKeever, Liam; Braunschweig, Carol

    2015-01-01

    Diagnostic computed tomography (CT) scans provide numerous opportunities for body composition analysis including quantification of abdominal circumference, abdominal adipose tissues (subcutaneous, visceral and intermuscular) and skeletal muscle (SM). CT scans are commonly performed for diagnostic purposes in clinical settings and methods for estimating abdominal circumference and whole-body SM mass from them have been reported. A supine abdominal circumference is a valid measure of waist circ...

  19. Modulation of Muscle Atrophy, Fatigue and MLC Phosphorylation by MuRF1 as Indicated by Hindlimb Suspension Studies on MuRF1-KO Mice

    Siegfried Labeit

    2010-01-01

    Full Text Available MuRF1 is a member of the TRIM/RBCC superfamily, a gene family that encompasses a large variety of proteins, all sharing the conserved TRIM (Tripartite Motive sequential array of RING, B-box, and coiled-coil domains. Within this family, MuRF1(also named TRIM63 is a specialized member that contributes to the development of muscle atrophy and sarcopenia. Here we studied MuRF1's role in muscle atrophy during muscle unloading induced by hindlimb suspension. Consistent with previous studies, we found that MuRF1 inactivation leads to an attenuated muscle atrophy response. The amount of protection was higher as compared to the denervation model, and within the 10 day-suspension period the soleus muscle was spared from atrophy in MuRF1-KO mice. Contractility studies on hindlimb suspended muscle tissues suggested that MuRF1's functions extend beyond muscle trophicity and implicate MuRF1 in muscle fatigue and MLC phosphorylation control: soleus muscle from MuRF1-KO mice fatigued significantly faster and in addition showed a reduced posttetanic twitch potentiation. Thus the present work further established the role of MuRF1 in muscle atrophy and for the first time shows that MuRF1 plays a role in muscle fatigue and twitch potentiation.

  20. Mapping quantitative trait loci affecting fatness and breast muscle weight in meat-type chicken lines divergently selected on abdominal fatness

    Neau André

    2006-01-01

    Full Text Available Abstract Quantitative trait loci (QTL for abdominal fatness and breast muscle weight were investigated in a three-generation design performed by inter-crossing two experimental meat-type chicken lines that were divergently selected on abdominal fatness. A total of 585 F2 male offspring from 5 F1 sires and 38 F1 dams were recorded at 8 weeks of age for live body, abdominal fat and breast muscle weights. One hundred-twenty nine microsatellite markers, evenly located throughout the genome and heterozygous for most of the F1 sires, were used for genotyping the F2 birds. In each sire family, those offspring exhibiting the most extreme values for each trait were genotyped. Multipoint QTL analyses using maximum likelihood methods were performed for abdominal fat and breast muscle weights, which were corrected for the effects of 8-week body weight, dam and hatching group. Isolated markers were assessed by analyses of variance. Two significant QTL were identified on chromosomes 1 and 5 with effects of about one within-family residual standard deviation. One breast muscle QTL was identified on GGA1 with an effect of 2.0 within-family residual standard deviation.

  1. Effect of pre-exercise phototherapy applied with different cluster probe sizes on elbow flexor muscle fatigue.

    Rossato, Mateus; Dellagrana, Rodolfo A; Lanferdini, Fábio J; Sakugawa, Raphael L; Lazzari, Caetano D; Baroni, Bruno M; Diefenthaeler, Fernando

    2016-08-01

    Phototherapy has been used for reducing muscle fatigue. In view of the various types of phototherapy cluster probes available in the market, the purpose of this study was to compare the effects of a similar phototherapy dosage with two different cluster probes on elbow flexor muscle fatigue: small cluster probe (SC = 9 diodes; 7.5 cm(2)) vs. large cluster probe (LC = 33 diodes; 30.2 cm(2)). Ten physically active male aged 18-35 years participate in a randomized, crossover, double-blind, placebo-controlled trial, which each participant was submitted to the same testing protocol in four sessions (separated by at least 48 h) with different treatments: LC-phototherapy, SC-phototherapy, LC-placebo, and SC-placebo. The elbow flexion maximal isometric voluntary contraction (MIVC) was performed before and after a fatigue protocol (60 % of MIVC until exhaustion). Electromyography (EMG) of the biceps brachii muscle was collected during all testing procedure. Phototherapy with dose of 60 J per muscle [LC: 33 diodes = 5 lasers (850 nm), 12 LEDs (670 nm), 8 LEDs (880 nm), and 8 LEDs (950 nm); SC: 9 diodes = 5 lasers (850 nm) and 4 LEDs (670 nm)] or placebo applications occurred before fatigue protocol. Two-way ANOVA (treatment and time factors) and one-way ANOVA were used, followed by LSD post hoc. Time to exhaustion was significantly higher in active LC (15 %; p = 0.031) and SC (14 %; p = 0.038) in comparison with their respective placebo treatments, without differences between LC and SC (p > 0.05) or between placebo conditions (p > 0.05). This larger exercise tolerance in phototherapy conditions was not accompanied by a higher decrement in the volunteers' maximal strength capacity (11-15 %; p > 0.05 for all). EMG signals presented no difference between the four condition tested here. In both large and small cluster probes (according parameters tested in this study) led to reduced fatigue in elbow flexor muscles, without

  2. Effects of leg muscle fatigue on gait in patients with Parkinson's disease and controls with high and low levels of daily physical activity.

    Santos, Paulo Cezar Rocha; Gobbi, Lilian Teresa Bucken; Orcioli-Silva, Diego; Simieli, Lucas; van Dieën, Jaap H; Barbieri, Fabio Augusto

    2016-06-01

    Patients with Parkinson's disease (PD) are more susceptible to muscle fatigue, which can damage their gait. Physical activity can improve muscle condition, which is an important aspect during walking. The aim of this study was to analyze the effects of lower limb muscle fatigue on gait in patients with PD and healthy individuals, grouped according to physical activity level. Twenty Patients with PD (PD group) and 20 matched individuals (control group) were distributed according to physical activity level into four subgroups of ten individuals (active and inactive). Participants performed three walking trials before and after lower limb muscle fatigue, induced by a repeated sit-to-stand task on a chair. Kinematic (stride length, width, duration, velocity and percentage of time in double support) and kinetic (propulsive and breaking anterior-posterior and medio-lateral impulse) gait parameters were analyzed. In both groups, participants increased stride length and velocity and decreased stride duration and braking vertical impulse after lower limb muscle fatigue. The PD groups presented higher step width and percentage of double time support than the control groups before muscle fatigue. The control groups increased step width and decreased percentage of time in double support, while the PD groups did not change these parameters. For physical activity level, active individuals presented longer stride length, greater stride velocity, higher braking and propulsive anterior-posterior impulse and shorter step width than inactive individuals. Groups sought more balance and safety after lower limb muscle fatigue. Physical activity level does not appear to modify the effects of lower limb muscle fatigue during unobstructed walking in individuals with PD or controls. PMID:27264409

  3. Single molecular image of cytosolic free Ca2+ of skeletal muscle cells in rats pre- and post-exercise-induced fatigue

    Liu, Yi; Zhang, Heming; Zhao, Yanping; Liu, Zhiming

    2009-08-01

    A growing body of literature indicated the cytosolic free Ca2+ concentration of skeletal muscle cells changes significantly during exercise-induced fatigue. But it is confusing whether cytosolic free Ca2+ concentration increase or decrease. Furthermore, current researches mainly adopt muscle tissue homogenate as experiment material, but the studies based on cellular and subcellular level is seldom. This study is aimed to establish rat skeletal muscle cell model of exercise-induced fatigue, and confirm the change of cytosolic free Ca2+ concentration of skeletal muscle cells in rats preand post- exercise-induced fatigue. In this research, six male Wistar rats were randomly divided into two groups: control group (n=3) and exercise-induced fatigue group (n=3). The former group were allowed to freely move and the latter were forced to loaded swimming to exhaustive. Three days later, all the rats were sacrificed, the muscle tissue from the same site of skeletal muscle were taken out and digested to cells. After primary culture of the two kinds of skeletal muscle cells from tissue, a fluorescent dye-Fluo-3 AM was used to label the cytosolic free Ca2+. The fluorescent of Ca2+ was recorded by confocal laser scanning microscopy. The results indicated that, the Ca2+ fluorescence intensity of cells from the rat of exercise-induced fatigue group was significantly higher than those in control group. In conclusion, cytosolic free Ca2+ concentration of skeletal muscle cells has a close relation with exercise-induced fatigue, and the increase of cytosolic free Ca2+ concentration may be one of the important factors of exercise-induced fatigue.

  4. Antioxidants Improve the Phenotypes of Dilated Cardiomyopathy and Muscle Fatigue in Mitochondrial Superoxide Dismutase-Deficient Mice

    Takahiko Shimizu

    2013-01-01

    Full Text Available Redox imbalance elevates the reactive oxygen species (ROS level in cells and promotes age-related diseases. Superoxide dismutases (SODs are antioxidative enzymes that catalyze the degradation of ROS. There are three SOD isoforms: SOD1/CuZn-SOD, SOD2/Mn-SOD, and SOD3/EC-SOD. SOD2, which is localized in the mitochondria, is an essential enzyme required for mouse survival, and systemic knockout causes neonatal lethality in mice. To investigate the physiological function of SOD2 in adult mice, we generated a conditional Sod2 knockout mouse using a Cre-loxP system. When Sod2 was specifically deleted in the heart and muscle, all mice exhibited dilated cardiomyopathy (DCM and died by six months of age. On the other hand, when Sod2 was specifically deleted in the skeletal muscle, mice showed severe exercise disturbance without morphological abnormalities. These provide useful model of DCM and muscle fatigue. In this review, we summarize the impact of antioxidants, which were able to regulate mitochondrial superoxide generation and improve the phenotypes of the DCM and the muscle fatigue in mice.

  5. Effect of muscular fatigue on fractal upper limb coordination dynamics and muscle synergies.

    Bueno, Diana R; Lizano, J M; Montano, L

    2015-08-01

    Rehabilitation exercises cause fatigue because tasks are repetitive. Therefore, inevitable human motion performance changes occur during the therapy. Although traditionally fatigue is considered an event that occurs in the musculoskeletal level, this paper studies whether fatigue can be regarded as context that influences lower-dimensional motor control organization and coordination at neural level. Non Negative Factorization Matrix (NNFM) and Detrended Fluctuations Analysis (DFA) are the tools used to analyze the changes in the coordination of motor function when someone is affected by fatigue. The study establishes that synergies remain fairly stable with the onset of fatigue, but the fatigue affects the dynamical coordination understood as a cognitive process. These results have been validated with 9 healthy subjects for three representative exercises for upper limb: biceps, triceps and deltoid. PMID:26737679

  6. Effects of normoxia and hyperoxia on the rate of fatigue development in human respiratory muscles under conditions of intensive resistive load.

    Segizbaeva, M O; Mironenko, M A

    2008-11-01

    We evaluated the rate of fatigue development in the inspiratory muscles of healthy trained individuals during graded bicycle exercise and high resistive resistance to breath under conditions of normoxia and hyperoxia. Fatigue of the respiratory muscles was assessed by tension-time index (TT(m)=P(m)I/P(m)I(maxx)T(I)/T(T)), by the dynamics of changes in the ratio of respiratory volume to inspiratory muscles force, and by ratio of the mean amplitudes of electrical activity in high and low frequency ranges. It was found that the limit of extreme working capacity in humans during heavy resistive load is related to fatigue of the inspiratory muscles developing with the same rate under conditions of normoxia or hyperoxia. PMID:19526089

  7. Effect of neck flexion restriction on sternocleidomastoid and abdominal muscle activity during curl-up exercises

    Lee, Dong-Kyu; Moon, Dong-chul; Hong, Ki-Hoon

    2016-01-01

    [Purpose] The purpose of this study was to investigate the effect of neck flexion restriction on sternocleidomastoid (SCM), rectus abdominis (RA), and external oblique (EO) muscle activity during a traditional curl-up exercise and a curl-up with neck flexion restriction. [Subjects] In total, 13 healthy male subjects volunteered for this study. [Methods] All subjects performed a traditional curl-up exercise and a curl-up exercise in which neck flexion was restricted by the subject’s hand. Surf...

  8. Subcellular distribution of glycogen and decreased tetanic Ca2+ in fatigued single intact mouse muscle fibres

    Nielsen, Joachim; Cheng, Arthur J; Ørtenblad, Niels; Westerblad, Hakan

    distribution by transmission electron microscopy. At fatigue, tetanic [Ca(2+)]i was reduced to 70 ± 4% and 54 ± 4% of the initial in HIF (P < 0.01, n = 9) and LIF (P < 0.01, n = 5) fibres, respectively. At fatigue, the mean inter- and intramyofibrillar glycogen content was 60-75% lower than in rested control...

  9. The Effects of Load Carriage and Muscle Fatigue on Lower-Extremity Joint Mechanics

    Wang, He; Frame, Jeff; Ozimek, Elicia; Leib, Daniel; Dugan, Eric L.

    2013-01-01

    Military personnel are commonly afflicted by lower-extremity overuse injuries. Load carriage and muscular fatigue are major stressors during military basic training. Purpose: To examine effects of load carriage and muscular fatigue on lower-extremity joint mechanics during walking. Method: Eighteen men performed the following tasks: unloaded…

  10. Bioprosthetic mesh of bacterial cellulose for treatment of abdominal muscle aponeurotic defect in rat model.

    Silveira, Raquel Kelner; Coelho, Antônio Roberto Barros; Pinto, Flávia Cristina Morone; de Albuquerque, Amanda Vasconcelos; de Melo Filho, Djalma Agripino; de Andrade Aguiar, José Lamartine

    2016-08-01

    The use of meshes for treatment of hernias continues to draw attention of surgeons and the industry in the search of an ideal prosthesis. The purpose of this work is to use meshes manufactured from bacterial cellulose, evaluate their organic tissue interaction and compare with an expanded polytetrafluorethylene (ePTFE's) prosthesis used to repair acute defect of muscle aponeurotic induced in rats. Forty-five male Wistar rats were classified using the following criteria: (1) surgical repair of acute muscle aponeurotic defect with perforated bacterial cellulose film (PBC; n = 18); (2) compact bacterial cellulose film (CBC; n = 12) and (3) ePTFE; (n = 15). After postoperative period, rectangles (2 × 3 cm) including prosthesis, muscles and peritoneum were collected for biomechanical, histological and stereological analysis. In all cases, the maximum acceptable error probability for rejecting the null hypothesis was 5 %. Between PBC and CBC samples, the variables of strain (P = 0.011) and elasticity (P = 0.035) were statistically different. The same was found between CBC and ePTFE (elasticity, P = 0.000; strain, P = 0.009). PBC differed from CBC for giant cells (P = 0.001) and new blood vessels (P = 0.000). In conclusion, there was biological integration and biomechanical elasticity of PBC; therefore, we think this option should be considered as a new alternative biomaterial for use as a bio prosthesis. PMID:27379627