Search Results
Results 301 - 350 of 1300
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Pereira Marta Inez R - - 2009
Cerebral contra-lateral frontal lobe and the dominant vastus lateralis muscle oxygenation (Cox, Mox) and blood volume (Cbv, Mbv) were recorded simultaneously using near infrared spectroscopy (NIRS) in 12 healthy volunteers (37.4 +/- 9.9 years; 72.3 +/- 16.1 kg; 171.0 +/- 9.6 cm) during 2 min resting baseline, an isometric knee ...
Baptista R R - - 2009
Skeletal muscle force production following repetitive contractions is preferentially reduced when muscle is evaluated with low-frequency stimulation. This selective impairment in force generation is called low-frequency fatigue (LFF) and could be dependent on the contraction type. The purpose of this study was to compare LFF after concentric and eccentric maximal ...
Gardner A Scott - - 2009
Previous investigators have quantified fatigue during short maximal cycling trials ( approximately 30 s) by calculating a fatigue index. Other investigators have reported a curvilinear power-pedaling rate relationship during short fatigue-free maximal cycling trials (<6 s). During maximal trials, pedaling rates may change with fatigue. Quantification of fatigue using fatigue ...
Lin Dingding - - 2009
The purposes of this study were to investigate the effects of fatigue location and age on changes in postural control induced by localized muscle fatigue, as well as the patterns of recovery post-fatigue. Groups of 16 younger (18-25 years) and 16 older (55-65 years) participants performed submaximal isotonic fatiguing exercises ...
White A T - - 2009
BACKGROUND: Multiple sclerosis (MS) patients experience fatigue as a chronic symptom that decreases quality of life. Commonly, fatigue in MS patients is manifested as decreased motor function during or after physical activity and is associated with changes in brain metabolism. OBJECTIVE: To determine brain activation patterns in MS patients and ...
Moraes Antonio C - - 2009
OBJECTIVE: The aim of this study was to describe by means of surface electromyography the activation of the rectus abdominis, obliquus externus and rectus femoris muscles during the "crunch" abdominal exercise performed with loads. METHODS: Thirteen subjects performed crunch exercises with loads representing 80, 60, 40 and 20% of the ...
Dritsa Maria - - 2009
OBJECTIVES: (1) To explore moderators of the effects of home-based exercise on reductions in physical and mental fatigue scores in postpartum depressed women and (2) to explore mediators of the intervention on changes in physical fatigue. METHOD: Eighty-eight women in the postpartum period (4-38 weeks) obtaining a score >or=10 on ...
Shibuya Kenichi - - 2009
Previous studies have investigated the relationship between prefrontal cortex activation and perceived exertion during prolonged exercise. However, the effect of perceived exertion on prefrontal cortex activity is confounded by exercise intensity. Therefore, the changes in prefrontal cortex activity in response to perceived exertion remain unclear. The purpose of the present ...
Windsor P M - - 2009
AIMS: An observational cohort study in patients undergoing treatment at a single cancer centre to evaluate the usefulness of providing written information on exercise and fatigue to patients at the start of their treatment, to assess whether patients exercised during treatment and their level of fatigue before and after treatment. ...
Girard Olivier - - 2010
The alteration in neuromuscular function of knee extensor muscles was characterised after a squash match in 10 trained players. Maximal voluntary contraction (MVC) and surface EMG activity of vastus lateralis (VL) and vastus medialis (VM) muscles were measured before and immediately after a 1-h squash match. M-wave and twitch contractile ...
Gauche Elodie - - 2009
PURPOSE: This study investigated neuromuscular fatigue following high versus low-intensity eccentric exercise corresponding to the same amount of work. METHODS: Ten volunteers performed two eccentric exercises of the elbow flexors: a high-intensity versus a low-intensity exercise. Maximal voluntary contraction torque and surface electromyography of the biceps brachii muscle were recorded ...
Oncu Jülide - - 2009
OBJECTIVE: To investigate and compare the impact of hospital and home exercise programmes on aerobic capacity, fatigue, and quality of life in patients with post-polio syndrome. DESIGN: A prospective, randomized controlled trial. SETTING: Department of Physical Medicine and Rehabilitation, University Hospital. SUBJECTS: Thirty-two patients were divided into two groups for ...
Yu Xiaoming - - 2009
Critical swimming speed (U(crit)) and tail-flip speed of kuruma shrimp, Marsupenaeus japonicus (9.92+/-0.60 cm, 10.18+/-1.89 g) were determined at 25-26 degrees C. Metabolite concentrations in hemolymph, pleopods and abdominal muscles, and hepatopancreas were measured before exercise and immediately after exercise fatigue to evaluate physiological effect of exercise in M. japonicus. ...
Maes Michael - - 2009
PURPOSE OF REVIEW: The aim of this paper is to review recent findings on inflammatory and oxidative and nitrosative stress (IO&NS) pathways in chronic fatigue and somatization disorder. RECENT FINDINGS: Activation of IO&NS pathways is the key phenomenon underpinning chronic fatigue syndrome (CFS): intracellular inflammation, with an increased production of ...
Billaut François - - 2009
Females have often been reported to have a greater muscle fatigue resistance than males, especially during exercise at low-to-moderate intensities. Differences in muscle mass, muscle metabolism and voluntary activation patterns have been the primary explanations for the differences in performance and physiological responses to exercise between sexes. However, while ample ...
Tseng Benjamin Y - - 2009
BACKGROUND: Fatigue is a commonly neglected issue despite the high incidence rate reported in people post-stroke. OBJECTIVE: To explore the relationship between fatigue, aerobic fitness, and motor control in people with chronic stroke. METHODS: Nine people post-stroke participated in this cross-sectional study (7 females, mean age = 56.8 (11.8) years, ...
Ament Wim - - 2009
Physical exercise affects the equilibrium of the internal environment. During exercise the contracting muscles generate force or power and heat. So physical exercise is in fact a form of mechanical energy. This generated energy will deplete the energy stocks within the body. During exercise, metabolites and heat are generated, which ...
Schwartz Fabiano P FP Department of Electrical Engineering, University of Brasília, Brasília, DF 70910-900 Brazil. - - 2009
Efficiency of muscular work is usually measured as the relationship between work load and maximum exercise duration. The present study analyzes the efficiency feature as a ratio between mechanical work (WK) and the energy (E) of the surface electromyographic signal (SEMG). This relation (WK/E(SEMG)) was compared with the most common ...
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 ...
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