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Sidhu Simranjit K - - 2009
Muscle fatigue is a reduction in the capacity to exert force and may involve a "central" component originating in the brain and/or spinal cord. Here we examined whether supraspinal factors contribute to impaired central drive after locomotor endurance exercise. On 2 separate days, 10 moderately active individuals completed a locomotor ...
Boland Michael R - - 2008
PURPOSE: The function of the brachioradialis muscle is controversial. The objective of this study was to determine primary and secondary functions of the brachioradialis under various loading tasks as measured by EMG. METHODS: Ten healthy individuals (9 men, 1 woman; average age, 34 years +/- 10; average height, 175 cm ...
Butcher S J - - 2009
Dynamic hyperinflation and leg muscle fatigue are independently associated with exercise limitation in patients with chronic obstructive pulmonary disease (COPD). The aims of the present study were to examine 1) the relationship between these limitations and 2) the effect of delaying ventilatory limitation on exercise tolerance and leg muscle fatigue. ...
Calder Kristina M - - 2009
The purpose of this study was to determine whether spike shape analysis of surface electromyographic (SEMG) activity is a useful tool to study muscle disorders. This study investigated SEMG spike shape parameters at low levels of contraction and changes in SEMG spike shape across different levels of isometric wrist extension ...
Takahashi Kyohei - - 2009
OBJECTIVE: This study was designed to examine whether exhaustive grip exercise of the left hand affected intracortical excitability in ipsilateral motor cortex. METHODS: Ten healthy male subjects (aged 21-24 years) participated in experiment 1 in which paired-pulse transcranial magnetic stimulation (TMS) was used to test corticospinal and corticocortical excitability in ...
Hortobágyi Tibor - - 2009
Although there is consensus that the central nervous system mediates the increases in maximal voluntary force (maximal voluntary contraction, MVC) produced by resistance exercise, the involvement of the primary motor cortex (M1) in these processes remains controversial. We hypothesized that 1-Hz repetitive transcranial magnetic stimulation (rTMS) of M1 during resistance ...
Braun U - - 2008
A 3.5 MHz linear transducer was used to assess the motility of the reticulum in 30 healthy, standing, non-sedated cows while they were at rest, eating, ruminating and under stress. The ultrasonographic examinations were made over periods of nine minutes and video recorded for analysis. The reticulum contracted in a ...
Ebben W P - - 2009
This study evaluated the biceps femoris (BF), rectus femoris (RF), and vastus lateralis (VL) activation and activation ratios of a variety of resistance training exercises characterized by knee extension, and determined if subject strength or gender affects these variables. The exercises evaluated included the leg extension, squat, deadlift, lunge, and ...
Kobayashi Yvonne M YM Howard Hughes Medical Institute, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, 4283 Carver Biomedical Research Building, 285 Newton Road, Iowa City, Iowa 52242-1101, - - 2008
Many neuromuscular conditions are characterized by an exaggerated exercise-induced fatigue response that is disproportionate to activity level. This fatigue is not necessarily correlated with greater central or peripheral fatigue in patients, and some patients experience severe fatigue without any demonstrable somatic disease. Except in myopathies that are due to specific ...
Joe Chang Che-Hsu CH Department of Environmental Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, 02115, USA. - - 2009
A repeated-measures laboratory experiment tested whether keystroke duration during touch-typing changes after a finger performs submaximal isometric flexion exercises. Fourteen right-handed touch-typists used right ring finger to perform three 15-min exercise conditions, two isometric exercises and a no-force condition, each on a separate day. Before and after each exercise condition, ...
Morana Claire - - 2009
This study aimed to assess the capacity of recurrence quantification analysis (RQA) to detect potentiation and to determine the fatigue components to which RQA is sensitive. Fifteen men were divided in two groups [8 endurance-trained athletes (END) and 7 power-trained athletes (POW)]. They performed a 10-min intermittent (5s contraction, 5s ...
Esposito Fabio - - 2009
To determine the differences between rock-climbers and controls in finger flexor (FF) motor units (MUs) features and activation strategy, eleven climbers and ten controls volunteered for the study. After maximal voluntary contraction (MVC) assessment, five levels of isometric contractions at 20, 40, 60, 80 and 100% MVC were performed. During ...
Mohammadi H - - 2008
Pyrolytic carbon mechanical heart valves (MHVs) are widely used to replace dysfunctional and failed heart valves. As the human heart beats around 40 million times per year, fatigue is the prime mechanism of mechanical failure. In this study, a finite element approach is implemented to develop a model for fatigue ...
Coquart Jeremy B J - - 2009
The purpose of this study was to examine the effects of a succession of fatiguing stages, on ratings of perceived exertion (RPE) and estimated time limits (ETL) during an incremental exercise test. Twenty-seven cyclists performed a continuous incremental test and a discontinuous test with randomized workloads. A linear mixed model ...
Amann Markus M John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin-Madison Medical School, Madison, Wisconsin, USA. - - 2008
We investigated whether somatosensory feedback from contracting limb muscles exerts an inhibitory influence on the determination of central command during closed-loop cycling exercise in which the subject voluntarily determines his second-by-second central motor drive. Eight trained cyclists performed two 5-km time trials either without (5K(Ctrl)) or with lumbar epidural anesthesia ...
Straub Cynthia K - - 2008
Fatigue is a common, debilitating symptom that has a negative effect on the overall well being of many patients on dialysis. This quasi-experimental pilot study used a pretest, posttest design to examine the effects of exercise on perceived levels offatigue as well as any physical performance changes in lower extremity ...
Ko Yi-Li - - 2008
This study explored the effectiveness of an exercise program on reducing levels of fatigue and depression among postpartum women who were "doing-the-month" in a maternity center in Taiwan. Previous studies related to postpartum have focused on depression rather than women's feelings of fatigue, and no study related to exercise has ...
Ullrich Boris - - 2008
In this study, we examined whether different exercise modes provoke functional differences in maximal and explosive force-generating capacities and fatigability of the quadriceps femoris (QF). Additionally, the interaction of different functional capacities was studied in competitive athletes. Ten competitive tennis players and 10 endurance athletes participated in the study. Pre-exercise ...
Verges Samuel - - 2009
This study aimed to 1) compare electrical and magnetic stimulations for quadriceps muscle function assessment, and 2) ascertain whether the ratios of the second twitch elicited by supramaximal electrical and magnetic femoral nerve stimulation at 10 and 100 Hz (T2(10:100)) and the total twitch force elicited by the same types ...
Dundon James M - - 2008
The purpose of this study was to quantify the association between low-frequency fatigue (LFF) and the increase in EMG and force fluctuations after eccentric exercise of elbow flexor muscles. Ten subjects performed two tasks involving voluntary isometric contractions of elbow flexors: a maximum voluntary contraction (MVC) and a constant-force task ...
Lou Jau-Shin - - 2008
Fatigue is a common and potentially debilitating symptom of amyotrophic lateral sclerosis (ALS). Questionnaire studies show that ALS subjects have increased subjective fatigue. Physiologic studies demonstrate that ALS subjects have increased physical fatigue, both central and peripheral in origin. No treatment has been proved effective through evidence-based medicine; however, modafinil ...
Mitchell Sarah M - - 2008
This study examined the effects of pulsed shortwave diathermy on intramuscular temperature, surface electromyography (EMG), and mechanomyography (MMG) of the vastus lateralis. Thirty-five men were assigned to diathermy (n = 13), sham-diathermy (n = 12), or control (n = 10) groups. Each subject performed isometric maximal voluntary contractions (MVCs) and ...
Mileva Katya N - - 2009
The aim of this study was to determine whether low-frequency whole-body vibration (WBV) modulates the excitability of the corticospinal and intracortical pathways related to tibialis anterior (TA) muscle activity, thus contributing to the observed changes in neuromuscular function during and after WBV exercise. Motor-evoked potentials (MEPs) elicited in response to ...
Leal Junior Ernesto Cesar Pinto - - 2009
This study aimed to investigate the effect of 830 nm low-level laser therapy (LLLT) on skeletal muscle fatigue. Ten healthy male professional volleyball players entered a crossover randomized double-blinded placebo-controlled trial. Active LLLT (830 nm wavelength, 100 mW output, spot size 0.0028 cm(2), 200 s total irradiation time) or an ...
Kimura Tetsuya - - 2008
The present study examined whether the mechanomyogram (MMG) could assess the fatigue-related changes in muscle mechanical properties during cycle exercise. In eight male subjects, the MMG signals were measured in vastus lateralis and rectus femoris by electret condenser microphones. It was found that the integrated MMG (iMMG) showed non linear ...
Baudry Stéphane - - 2008
The purpose of this study was to examine the effects of postactivation potentiation (PAP) on the torque and rate of torque development for contractions evoked by short trains of stimuli at different frequencies, in young and elderly adults. Individual mechanical contributions to each electrical stimulus within trains were also analysed. ...
Decorte Nicolas - - 2008
INTRODUCTION: Oral beta2-agonist administration improves muscle function in persons without asthma. We performed a double-blind, randomized, controlled crossover study to assess whether acute inhaled salbutamol administration improves muscle strength and fatigability in healthy moderately trained subjects. METHODS: Quadriceps muscle strength was measured during maximal voluntary contraction (MVC) and femoral nerve ...
Umeda Takashi - - 2008
To clarify the physical and mental fatigue caused by intense exercise and the relationship between the two types of fatigue, we examined changes in anthropometric and biochemical variables, neutrophil function, and the Profile of Mood States (POMS) questionnaire in 13 female university judoists attending a one-week training camp. Blood glucose, ...
Mulder E R - - 2008
The contractile characteristics of fast voluntary and electrically evoked unilateral isometric knee extensions were followed in 16 healthy men during 56 days of horizontal bed rest and assessed at bed rest days 4, 7, 10, 17, 24, 38 and 56. Subjects were randomized to either an inactive control group (Ctrl, ...
Cairns S P - - 2008
During intense exercise or electrical stimulation of skeletal muscle the concentrations of several ions change simultaneously in interstitial, transverse tubular and intracellular compartments. Consequently the functional effects of multiple ionic changes need to be considered together. A diminished transsarcolemmal K(+) gradient per se can reduce maximal force in non-fatigued muscle ...
Bercier Stephane - - 2009
OBJECTIVE: The objective of this work was to study modifications in motor control through surface electromyographic (sEMG) activity during a very short all-out cycling exercise. METHODS: Twelve male cyclists (age 23+/-4 years) participated in this study. After a warm-up period, each subject performed three all-out cycling exercises of 6s separated ...
Arabadzhiev Todor I - - 2008
The influence of changes in the intracellular action potential (IAP) spatial profile on motor unit potentials (MUPs), number of turns per second (NTs), and mean turn amplitude were simulated and analyzed. We show why measurement of NTs was "the best indicator of neurogenic affection" and why the lower diagnostic yield ...
Damon Bruce M BM Institute of Imaging Science, Vanderbilt University, Nashville, TN 37232, USA. - - 2008
It has previously been observed that during isometric dorsiflexion exercise, the time course of T2-weighted signal intensity (SI) changes is spatially heterogeneous. The purpose of this study was to test the hypothesis that this spatial heterogeneity would increase at higher contraction intensities. Eight subjects performed 90-s isometric dorsiflexion contractions at ...
Oliveira Anderson de Souza Castelo Ade - - 2009
The aim of this study was to evaluate the EMG activity of lumbar multifidus (MU), longissimus thoracis (LT) and iliocostalis (IC) muscles during an upper limb resistance exercise (biceps curl). Ten healthy males performed maximal voluntary isometric contraction (MVC) of the trunk extensors, after this, the biceps curl exercise was ...
El Mhandi Lhassan - - 2008
Exercise intolerance and undue fatigue are common complaints in patients with Charcot-Marie-Tooth (CMT) disease. Reduced physical ability is due directly to the disease, but it is also due to physical deconditioning. The aim of this study was to test whether 24 weeks of interval-training exercise (ITE) cycling can significantly improve ...
Nijs Jo - - 2008
OBJECTIVE: It was hypothesized that the use of exercise limits prevents symptom increases and worsening of their health status following a walking exercise in people with chronic fatigue syndrome. DESIGN: An uncontrolled clinical trial (semi-experimental design). SETTING: Outpatient clinic of a university department. SUBJECTS: Twenty-four patients with chronic fatigue syndrome. ...
Saito Yoko - - 2008
PURPOSE: Females have been reported to have greater resistance to skeletal muscle fatigue than males. Blood flow, which plays an important role in supplying oxygen and nutrients to working muscles, may play an important role in the mechanisms of gender difference. We hypothesized that females would have greater conduit artery ...
Dimeo F - - 2008
BACKGROUND: Fatigue is a relevant problem of cancer patients during and after treatment. Several studies have shown that exercise can improve quality of life and functional status of cancer patients undergoing chemo- or radiotherapy. However, there is a lack of information about the effects of this intervention on persistent cancer-related ...
Nijs Jo J Division of Musculoskeletal Physiotherapy, Department of Health Care Sciences, University College Antwerp, Vrije Universiteit Brussel, Belgium. - - 2008
Controversy regarding the aetiology and treatment of patients with chronic fatigue syndrome continues among the medical professions. The Cochrane Collaboration advises practitioners to implement graded exercise therapy for patients with chronic fatigue syndrome using cognitive behavioural principles. Conversely, there is evidence that exercise can exacerbate symptoms in chronic fatigue syndrome, ...
Harvey Samuel B SB Institute of Psychiatry, King's College London, London, UK. - - 2008
To review the etiology of chronic fatigue syndrome (CFS) and test hypotheses relating to immune system dysfunction, physical deconditioning, exercise avoidance, and childhood illness experiences, using a large prospective birth cohort. A total of 4779 participants from the Medical Research Council's National Survey of Health and Development were prospectively followed ...
White Kevin T - - 2008
Recent studies suggest that the Shaker exercise induces fatigue in the upper esophageal sphincter (UES) opening muscles and sternocleidomastoid (SCM), with the SCMs fatiguing earliest. The aim of this study was to measure fatigue induced by the isometric portion of the Shaker exercise by measuring the rate of change in ...
Thickbroom Gary W - - 2008
OBJECTIVE: To determine if task performance and fatigability during rapid repetitive exercise of the lower limb differ in a group of MS subjects compared to a control group, and what central changes accompany the development of fatigue and the period of recovery. METHODS: Transcranial magnetic stimulation (TMS) was used to ...
Taylor Bryan J - - 2008
High-intensity exercise (> or =90% of maximal O(2) uptake) sustained to the limit of tolerance elicits expiratory muscle fatigue (EMF). We asked whether prior EMF affects subsequent exercise tolerance. Eight male subjects (means +/- SD; maximal O(2) uptake = 53.5 +/- 5.2 ml.kg(-1).min(-1)) cycled at 90% of peak power output ...
Ting Ping-Huang - - 2008
Long duration of driving is a significant cause of fatigue-related accidents on motorways or major roadways. The fatigue caused by driving for extended periods acutely impairs driver alertness and performance and can compromise transportation safety. This study quantitatively measured the progression of driver fatigue and identified the conservative safe duration ...
McCullagh Ruth - - 2008
OBJECTIVE: To determine if exercise benefits patients with multiple sclerosis. DESIGN: Randomized controlled trial. SETTINGS: Participants exercised at home and also attended exercise classes held in a hospital physiotherapy gym. SUBJECTS: Thirty patients, diagnosed and independently mobile, were recruited in the Dublin area. INTERVENTION: For three months, classes were held ...
Dempsey Jerome A - - 2008
We briefly summarize recent evidence pertaining to how mechanisms primarily under the control of the respiratory system-namely, arterial oxyhemoglobin desaturation, respiratory muscle work and fatigue, and cyclical fluctuations in intrathoracic pressure-may contribute to exercise limitation. Respiratory influences on cardiac output and on sympathetic vasoconstrictor activity and blood flow distribution are ...
Stephen Sharon A - - 2008
PURPOSE: The purpose of this study was to describe fatigue and the relationships among fatigue intensity, self-reported functional status, and quality of life in older adults with stable heart failure. METHODS: A descriptive, correlational design was used to collect quantitative data with reliable and valid instruments. Fifty-three eligible volunteers completed ...
Jing L - - 2008
AIM: There are few researches on the effects of music therapy on the recovery from exercise-induced fatigue worldwide. The aim of this study was to evaluate the effects of relaxing music on aerobic exercise-induced fatigue. The authors' hypothesis is that relaxing music can effectively eliminate aerobic exercise-induced fatigue. METHODS: Thirty ...
Martins Jaqueline - - 2008
Imbalance and weakness of the serratus anterior and upper trapezius force couple have been described in patients with shoulder dysfunction. There is interest in identifying exercises that selectively activate these muscles and including it in rehabilitation protocols. This study aims to verify the UT/SA electromyographic (EMG) amplitude ratio, performed in ...
Lydakis C - - 2008
Chronic dynamic (aerobic) exercise decreases central arterial stiffness, whereas chronic resistance exercise evokes the opposite effect. Nevertheless, there is little information available on the effects of acute bouts of exercise. Also, there is limited data showing an increase of central arterial stiffness during acute mental stress. This study aimed to ...
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