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Low frequency fatigue

Alyssandra N Baniqued, Jorge M Zuniga, Thomas C Strunc, Katie M Keenan, Agrini K Boken, Jeffrey J Anderson
The purpose of this study was to determine if the amount of subcutaneous tissue over the quadriceps affects the assessment of mean power frequency at the fatigue threshold (MPFFT). It was hypothesized that greater skinfold values will result in lower power outputs associated to the MPFFT. Fourteen adults (Mean ± SD age = 20.7 ± 0.99; body weight = 72.8 ± 12.6 kg) performed an incremental cycle ergometry test to exhaustion while surface electromyographic (EMG) signals were measured from the vastus lateralis...
2016: International Journal of Exercise Science
Jonathan T Kaplan, Corey P Neu, Hicham Drissi, Nancy C Emery, David M Pierce
Osteoarthritis and articular cartilage injuries are common conditions in human joints and a frequent cause of pain and disability. Unfortunately, cartilage is avascular and has limited capabilities for self-repair. Despite the societal impact, there is little information on the dynamic process of cartilage degeneration. We performed a series of cyclic unconfined compression tests motivated by in vivo loading conditions and designed to generate mechanical fatigue. We examined the functional (both stress-stretch and creep) responses of the tissue after recovery from a specified number of loading cycles, as well as histology and second harmonic generation microscopy images...
October 1, 2016: Journal of the Mechanical Behavior of Biomedical Materials
Yasuhide Yoshitake, Hiroaki Kanehisa, Minoru Shinohara
PURPOSE: The purpose of this study was to determine the modulation of common low-frequency oscillations in pools of motor units across antagonistic muscles due to the difference in the activation level of pools of spinal motor neurons and the presence of neuromuscular fatigue during intended co-contraction. METHODS: Ten healthy young men (21.8 ± 1.5 yr) performed intended steady co-contractions of elbow flexors and extensors at maximal and a submaximal (10% of maximal electromyogram, EMG) effort...
October 6, 2016: Medicine and Science in Sports and Exercise
Zewei Wang, Qing Yang, Li Min Chen
The goals of this study are to characterize the temporal dynamics of inter-regional connectivity of the brain in chronic headache (CH) patients versus their age/gender matched controls (CONCH, n=28 pairs), and to determine whether dynamic measures reveal additional features to static functional connectivity and correlate with psychometric scores. Cortical thickness and inter-regional resting state fMRI connectivity were quantified and compared between CH and CONCH groups. Six cortical regions of interest (ROI) pairs that exhibited correlated cortical thickness and static functional connectivity abnormalities were selected for temporal dynamic analysis...
October 14, 2016: Magnetic Resonance Imaging
Marcus Yung, Richard P Wells
Many contemporary occupations are characterised by long periods of low loads. These lower force levels, which are relevant to the development of work-related musculoskeletal disorders, are usually not the focus of fatigue studies. In studies that did measure fatigue in light manual or precision work, within and between measurement responses were inconsistent. The aim of this study was to identify fatigue measures that were responsive at lower force levels (<10% MVC) over the course of an 8-h period. A complementary set of fatigue measures, reflecting both neuromuscular and cognitive mechanisms, was measured during a light precision micro-pipetting task performed by 11 participants...
October 14, 2016: Ergonomics
Elisa G Krächan, Alexander U Fischer, Jürgen Franke, Eckhard Friauf
At early stations of the auditory pathway, information is encoded in the precise signal timing and rate. Auditory synapses must maintain the relative timing of events with submillisecond precision even during sustained and high-frequency stimulation. In non-auditory brain regions, e.g. telencephalic ones, synapses are activated at considerably lower frequencies. Central to understanding the heterogeneity of synaptic systems is to elucidate the physical, chemical, and biological factors that determine synapse performance...
September 26, 2016: Journal of Physiology
G Muldaeva, N Rukaber, L Arystan, L Haydargalieva, Z Kenzhetaeva
The aim of this research was to determine the frequency and degree of severity of asthenic syndrome (AS) and estimation of physical health of women with iron-deficiency anemia (IDA) and without it. 30 women were inspected with the set diagnosis of IDA and 20 nearly were healthy. All participants were assessed according objective status. AS was determined by the scale of estimation of asthenia - Scale Asthenic Conditions (SAC) of LD Malkova, the scale of subjective evaluation of asthenia (MFI-20). Level of somatic health was appraised by methodology of LG Apanasenko...
July 2016: Georgian Medical News
Vijayshree Yadav, Gail Marracci, Edward Kim, Rebecca Spain, Michelle Cameron, Shannon Overs, Andrew Riddehough, David K B Li, John McDougall, Jesus Lovera, Charles Murchison, Dennis Bourdette
BACKGROUND: The role that dietary interventions can play in multiple sclerosis (MS) management is of huge interest amongst patients and researchers but data evaluating this is limited. Possible effects of a very-low-fat, plant-based dietary intervention on MS related progression and disease activity as measured by brain imaging and MS related symptoms have not been evaluated in a randomized-controlled trial. Despite use of disease modifying therapies (DMT), poor quality of life (QOL) in MS patients can be a significant problem with fatigue being one of the common disabling symptoms...
September 2016: Multiple Sclerosis and related Disorders
Clécio Gabriel de Souza, Daniel Tezoni Borges, Liane de Brito Macedo, Jamilson Simões Brasileiro
Low-level laser therapy (LLLT) has been suggested as a resource capable of increasing resistance to fatigue and enhancing muscle performance through its metabolic and photochemical effects. This study evaluated the immediate effects of the application of LLLT on neuromuscular performance of the plantar ankle flexors in healthy subjects through a fatigue-induced protocol. This is a randomized controlled clinical trial, attended by 60 young and physically active volunteers of both genders. The subjects were randomly assigned into three groups, control, placebo, and laser, and underwent a preliminary evaluation of the isokinetic performance of plantar flexors and electromyographic activity of the soleus muscle to ensure homogeneity between groups...
September 17, 2016: Lasers in Medical Science
Thomas Cattagni, Clément Billet, Christophe Cornu, Marc Jubeau
CONTEXT: The prolonged tendon vibration may induce muscle fatigue, as assessed by a decrease in maximal force production. It remains however unknown whether the decrease in muscle strength after prolonged Achilles tendon vibration is related to the vibration frequency. OBJECTIVE: This study aimed to assess the maximal capacity of plantar flexor neuromuscular function before and after prolonged Achilles tendon vibration at low and high frequencies generated using a portable device...
August 24, 2016: Journal of Sport Rehabilitation
Michele M Pelter, Richard Fidler, Xiao Hu
BACKGROUND: Although electrocardiographic monitoring is valuable for continuous surveillance of intensive care unit (ICU) patients, false alarms are common and have been cited as a cause of alarm fatigue. ANSI/AAMI EC12:2002 states that electrocardiograms (ECGs) should not detect a QRS if the waveform is less than 0.15 mV (1.5 mm) for adult patients, in order to avoid mislabeling P waves or baseline noise as QRSs during complete heart block or asystole. However, ECG software algorithms often use more conservative QRS thresholds, which may result in false-positive asystole alarms in patients with low-amplitude QRS complexes...
September 2016: Biomedical Instrumentation & Technology
Bruzas Vidas, Kamandulis Sigitas, Venckunas Tomas, Snieckus Audrius, Mockus Pranas
BACKGROUND: During competition, a boxer must continue to deliver high-impact punches despite increasing fatigue. It is unclear whether the effects of plyometric training using external weights are transferred to sport-specific movements such as punching. The aim of the study was to investigate the effects of a 4-week cycle of plyometric training with external weights on punching ability. METHODS: The study involved eight male amateur boxers aged 22.3±2.5 years with at least 7 years of competitive experience...
September 13, 2016: Journal of Sports Medicine and Physical Fitness
Reinier J Jansen, Ben D Sawyer, René van Egmond, Huib de Ridder, Peter A Hancock
OBJECTIVE: We examine how transitions in task demand are manifested in mental workload and performance in a dual-task setting. BACKGROUND: Hysteresis has been defined as the ongoing influence of demand levels prior to a demand transition. Authors of previous studies predominantly examined hysteretic effects in terms of performance. However, little is known about the temporal development of hysteresis in mental workload. METHOD: A simulated driving task was combined with an auditory memory task...
September 9, 2016: Human Factors
Hiroshi Kato, Naoto Sassa, Masayuki Miyazaki, Mio Takeuchi, Miho Asai, Akane Iwai, Yukihiro Noda, Momokazu Gotoh, Kiyofumi Yamada
PURPOSE: Axitinib is a selective tyrosine kinase inhibitor of VEGF receptors, approved for advanced renal cell carcinoma (RCC). Associations between axitinib plasma exposure, genetic polymorphisms of ABC transporters and axitinib-induced toxicities have not been adequately explored. METHODS: Twenty RCC patients treated with axitinib were enrolled in this study. Blood samples were collected 0, 0.5, 1, 2, 4, and 6 h after administration of axitinib on day 1 and at steady state...
October 2016: Cancer Chemotherapy and Pharmacology
Sara Alhanbali, Piers Dawes, Simon Lloyd, Kevin J Munro
OBJECTIVE: Hearing loss may increase listening-related effort and fatigue due to the increased mental exertion required to attend to, and understand, an auditory message. Because there have been few attempts to quantify self-reported effort and fatigue in listeners with hearing loss, that was the aim of the present study. DESIGN: Participants included three groups of hearing-impaired adults: (1) hearing aid users (HA, n = 50; 31 male, 19 female; age range = 55 to 85 years); (2) cochlear implant users (CI, n = 50; 26 male, 24 female; age range = 55 to 80 years); and (3) single sided deafness (SSD, n = 50; 30 male, 20 female; age range = 58 to 80 years)...
August 18, 2016: Ear and Hearing
Marlene Giandolini, Gianluca Vernillo, Pierre Samozino, Nicolas Horvais, W Brent Edwards, Jean-Benoît Morin, Guillaume Y Millet
Scientific experiments on running mainly consider level running. However, the magnitude and etiology of fatigue depend on the exercise under consideration, particularly the predominant type of contraction, which differs between level, uphill, and downhill running. The purpose of this review is to comprehensively summarize the neurophysiological and biomechanical changes due to fatigue in graded running. When comparing prolonged hilly running (i.e., a combination of uphill and downhill running) to level running, it is found that (1) the general shape of the neuromuscular fatigue-exercise duration curve as well as the etiology of fatigue in knee extensor and plantar flexor muscles are similar and (2) the biomechanical consequences are also relatively comparable, suggesting that duration rather than elevation changes affects neuromuscular function and running patterns...
October 2016: European Journal of Applied Physiology
Alexander G Barszap, Ida-Maria Skavhaug, Sanjay S Joshi
Electromyography-based human-computer interface development is an active field of research. However, knowledge on the effects of muscle fatigue for specific devices is limited. We have developed a novel myoelectric human-computer interface in which subjects continuously navigate a cursor to targets by manipulating a single surface electromyography (sEMG) signal. Two-dimensional control is achieved through simultaneous adjustments of power in two frequency bands through a series of dynamic low-level muscle contractions...
October 2016: Human Movement Science
Igor Belyaev, Amy Dean, Horst Eger, Gerhard Hubmann, Reinhold Jandrisovits, Markus Kern, Michael Kundi, Hanns Moshammer, Piero Lercher, Kurt Müller, Gerd Oberfeld, Peter Ohnsorge, Peter Pelzmann, Claus Scheingraber, Roby Thill
Chronic diseases and illnesses associated with non-specific symptoms are on the rise. In addition to chronic stress in social and work environments, physical and chemical exposures at home, at work, and during leisure activities are causal or contributing environmental stressors that deserve attention by the general practitioner as well as by all other members of the health care community. It seems necessary now to take "new exposures" like electromagnetic fields (EMF) into account. Physicians are increasingly confronted with health problems from unidentified causes...
September 1, 2016: Reviews on Environmental Health
Thomas Cattagni, Clément Billet, Christophe Cornu, Marc Jubeau
CONTEXT: The prolonged tendon vibration may induce muscle fatigue, as assessed by a decrease in maximal force production. It remains however unknown whether the decrease in muscle strength after prolonged Achilles tendon vibration is related to the vibration frequency. OBJECTIVE: This study aimed to assess the maximal capacity of plantar flexor neuromuscular function before and after prolonged Achilles tendon vibration at low and high frequencies generated using a portable device...
July 21, 2016: Journal of Sport Rehabilitation
Elisa Pelosin, Laura Avanzino, Roberta Barella, Cristina Bet, Elisabetta Magioncalda, Carlo Trompetto, Piero Ruggeri, Mauro Casaleggio, Giovanni Abbruzzese
BACKGROUND: Treadmill Training (TT) has been indicated as a potential therapeutic tool for improving balance and gait in patients with Parkinson's disease (PD). However, the lack of evidences about the best modality of intervention (e.g.: number of sessions) and the lack of reliable follow-up measures, made difficult to hand down these results into the clinical practice. AIM: To compare the efficacy of 3 different modalities of TT program on gait performance in PD patients...
July 19, 2016: European Journal of Physical and Rehabilitation Medicine
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