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vastus lateralis

Florian Husmann, Martin Gube, Sabine Felser, Matthias Weippert, Anett Mau-Moeller, Sven Bruhn, Martin Behrens
PURPOSE: Despite growing interest in task-dependent alterations of central and peripheral fatigue following endurance exercise, little is known about the impact of rowing on quadriceps muscle fatigue. This study aimed to investigate central and peripheral mechanisms of fatigue following a 2000-m rowing time-trial. METHODS: Eight competitive rowers (4 males, 4 females, 20 ± 4 years) performed a 2000-m time-trial on an indoor rower and a control condition (sitting)...
October 21, 2016: Medicine and Science in Sports and Exercise
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
Justin D La Favor, Gabriel S Dubis, Huimin Yan, Joseph D White, Margaret A M Nelson, Ethan J Anderson, Robert C Hickner
OBJECTIVE: The objectives of this study were to determine the impact of in vivo reactive oxygen species (ROS) on microvascular endothelial function in obese human subjects and the efficacy of an aerobic exercise intervention on alleviating obesity-associated dysfunctionality. APPROACH AND RESULTS: Young, sedentary men and women were divided into lean (body mass index 18-25; n=14), intermediate (body mass index 28-32.5; n=13), and obese (body mass index 33-40; n=15) groups...
October 20, 2016: Arteriosclerosis, Thrombosis, and Vascular Biology
Victor M Niemeijer, Ruud F Spee, Thijs Schoots, Pieter F F Wijn, Hareld M Kemps
The extent and speed of transient skeletal muscle deoxygenation during exercise onset in chronic heart failure (CHF) patients is related to impairments of local O2 delivery and utilization. This study examined the physiological background of submaximal exercise performance in 19 moderately impaired CHF patients (Weber class A, B, and C) compared with 19 matched healthy control (HC) subjects by measuring skeletal muscle oxygenation (SmO2) changes during cycling exercise. All subjects performed two subsequent moderate-intensity 6-minute exercise tests (bout 1 and 2) with measurements of pulmonary oxygen uptake kinetics, and SmO2 using near infrared (NIR) spatially resolved spectroscopy (SRS) at the vastus lateralis for determination of absolute oxygenation values, amplitudes, kinetics (mean response time for onset), and deoxygenation overshoot characteristics...
October 7, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Tsuyoshi Goto, Toshinori Sakai, Tetsuya Enishi, Nori Sato, Koji Komatsu, Koichi Sairyo, Shinsuke Katoh
Neurogenic intermittent claudication is a main symptom in lumbar spinal stenosis (LSS), and postural change is often observed during walking. This study aimed to identify the changes in posture and muscle activity in the trunk and legs during walking in patients with LSS by examining 6 patients who had undergone decompression surgery. None of them had significant paralysis. Gait analysis using Vicon motion capture system(®) with electromyographic recordings of the paravertebral muscles (PVM) and vastus lateralis muscle (VL) was performed preoperatively and 2 weeks postoperatively...
October 6, 2016: Gait & Posture
Hsing-Hua Tsai, Chin-Pu Lin, Yi-Hui Lin, Chih-Chin Hsu, Jong-Shyan Wang
PURPOSE: Exercise training improves endothelium-dependent vasodilation, whereas hypoxic stress causes vascular endothelial dysfunction. Monocyte-derived endothelial progenitor cells (Mon-EPCs) contribute to vascular repair process by differentiating into endothelial cells. This study investigates how high-intensity interval (HIT) and moderate-intensity continuous (MCT) exercise training affect circulating Mon-EPC levels and EPC functionality under hypoxic condition. METHODS: Sixty healthy sedentary males were randomized to engage in either HIT (3-min intervals at 40 and 80 % VO2max for five repetitions, n = 20) or MCT (sustained 60 % VO2max, n = 20) for 30 min/day, 5 days/week for 6 weeks, or to a control group (CTL) that did not received exercise intervention (n = 20)...
October 19, 2016: European Journal of Applied Physiology
Cory M Smith, Terry J Housh, Nathaniel D M Jenkins, Ethan C Hill, Kristen C Cochrane, Amelia A Miramonti, Richard J Schmidt, Glen O Johnson
The purposes of the present study were to apply a unique method for the identification of the time course of changes in neuromuscular responses and to infer the motor unit activation strategies used to maintain force during a fatiguing, intermittent isometric workbout. Eleven men performed 50, 6 s intermittent isometric muscle actions of the leg extensors, each separated by 2 s of rest at 60% maximal voluntary isometric contraction (MVIC). Electromyographic (EMG) and mechanomyographic (MMG) amplitude (root mean square; RMS) and frequency (mean power frequency; MPF) were obtained from the vastus lateralis (VL) every 5 of the 50 repetitions and normalized as a percent of the initial repetition...
October 18, 2016: Physiological Measurement
Joanna Majerczak, Marcin Grandys, Krzysztof Duda, Agnieszka Zakrzewska, Aneta Balcerczyk, Leszek Kolodziejski, Dorota Szymoniak-Chochol, Ryszard T Smolenski, Grzegorz Bartosz, Stefan Chlopicki, Jerzy A Zoladz
In this study we have evaluated the effect of 20-weeks of moderate-intensity endurance training (ET) on the endothelial glycocalyx layer integrity in relation to the training-induced changes in antioxidant defence. Eleven healthy young, untrained men performed an incremental cycling exercise until exhaustion before and after 20 weeks of ET. Endurance training consisted of 40- minute sessions, mainly of moderate-intensity (∼50% of VO2max ), performed 4 times per week. Venous blood samples were taken at rest and at the end of the maximal exercise test...
October 17, 2016: Experimental Physiology
Sebastian Frese, Jens A Petersen, Maria Ligon-Auer, Sandro Manuel Mueller, Violeta Mihaylova, Saskia M Gehrig, Veronika Kana, Elisabeth J Rushing, Evelyn Unterburger, Georg Kägi, Jean-Marc Burgunder, Marco Toigo, Hans H Jung
Huntington disease (HD) is a relentlessly progressive neurodegenerative disorder with symptoms across a wide range of neurological domains, including cognitive and motor dysfunction. There is still no causative treatment for HD but environmental factors such as passive lifestyle may modulate disease onset and progression. In humans, multidisciplinary rehabilitation has a positive impact on cognitive functions. However, a specific role for exercise as a component of an environmental enrichment effect has been difficult to demonstrate...
October 17, 2016: Journal of Neurology
Christoph Zinner, David Morales-Alamo, Niels Ørtenblad, Filip J Larsen, Tomas A Schiffer, Sarah J Willis, Miriam Gelabert-Rebato, Mario Perez-Valera, Robert Boushel, Jose A L Calbet, Hans-Christer Holmberg
To elucidate the mechanisms underlying the differences in adaptation of arm and leg muscles to sprint training, over a period of 11 days 16 untrained men performed six sessions of 4-6 × 30-s all-out sprints (SIT) with the legs and arms, separately, with a 1-h interval of recovery. Limb-specific VO2peak, sprint performance (two 30-s Wingate tests with 4-min recovery), muscle efficiency and time-trial performance (TT, 5-min all-out) were assessed and biopsies from the m. vastus lateralis and m. triceps brachii taken before and after training...
2016: Frontiers in Physiology
Masahiro Horiuchi, Yoko Handa, Daijiro Abe, Yoshiyuki Fukuoka
We measured oxygen consumption during walking per unit distance (Cw) values for 12 human healthy young males at six speeds from 0.667 to 1.639 m s(-1) (four min per stage) on a level gradient under normobaric normoxia, moderate hypoxia (15% O2), and severe hypoxia (11% O2). Muscle deoxygenation (HHb) was measured at the vastus lateralis muscle using near-infrared spectroscopy. Economical speed which can minimize the Cw in each individual was calculated from a U-shaped relationship. We found a significantly slower economical speed (ES) under severe hypoxia [1...
October 15, 2016: Biology Open
Luca Mesin, Davide Dardanello, Alberto Rainoldi, Gennaro Boccia
During fatiguing contractions, many adjustments in motor units behaviour occur: decrease in muscle fibre conduction velocity; increase in motor units synchronisation; modulation of motor units firing rate; increase in variability of motor units inter-spike interval. We simulated the influence of all these adjustments on synthetic EMG signals in isometric/isotonic conditions. The fractal dimension of the EMG signal was found mainly influenced by motor units firing behaviour, being affected by both firing rate and synchronisation level, and least affected by muscle fibre conduction velocity...
October 12, 2016: Medical Engineering & Physics
Amy E Mendham, Rob Duffield, Aaron J Coutts, Frank E Marino, Andriy Boyko, Andrew J McAinch, David John Bishop
PURPOSE: This study assessed the mitochondrial related signaling responses to a single bout of non-contact, modified football (touch rugby), played as small-sided games (SSG), or cycling (CYC) exercise in sedentary, obese, middle-aged men. METHOD: In a randomized, cross-over design, nine middle-aged, sedentary, obese men completed two, 40-min exercise conditions (CYC and SSG) separated by a 21-d recovery period. Heart rate (HR) and Ratings of Perceived Exertion were collected during each bout...
October 14, 2016: Journal of Applied Physiology
Ashraf S Gorgey, Zachary A Graham, William A Bauman, Christopher Cardozo, David R Gater
STUDY DESIGN: Longitudinal design. OBJECTIVES: The study determined the effects of two forms of exercise training on the abundance of two proteins, (glucose transporter-4 [GLUT-4], adenosine monophosphate kinase [AMPK]) involved in glucose utilization and the transcriptional coactivator that regulates the genes involved in energy metabolism and mitochondrial biogenesis (peroxisome proliferator-activated receptor (PPAR) coactivator 1 alpha [PGC-1α]), in muscles in men with chronic motor-complete spinal cord injury (SCI)...
October 13, 2016: Journal of Spinal Cord Medicine
R Pellini, A De Virgilio, G Mercante, B Pichi, V Manciocco, P Marchesi, F Ferreli, G Spriano
In the last decade, the antero-lateral thigh free flap (ALT) has become the most popular free flap for tongue reconstruction because of less donor site morbidity and better cosmetic outcomes. However, fascio-cutaneous ALT may be insufficient to reconstruct major tongue defects, while its muscular-cutaneous variant (using the vastus lateralis muscle) may be too bulky. The present study describes our preliminary experience of tongue reconstruction with vastus lateralis myofascial flap, which could potentially offer unique advantages in head and neck reconstruction including adequate bulk when needed, optimal functional results and obliteration of dead space thus preventing fistulas and infections with minimal morbidity...
August 2016: Acta Otorhinolaryngologica Italica
David C Nieman, Kevin A Zwetsloot, Dominic D Lomiwes, Mary P Meaney, Roger D Hurst
The cytokine response to heavy exertion varies widely for unknown reasons, and this study evaluated the relative importance of glycogen depletion, muscle damage, and stress hormone changes on blood and muscle cytokine measures. Cyclists (N = 20) participated in a 75-km cycling time trial (168 ± 26.0 min), with blood and vastus lateralis muscle samples collected before and after. Muscle glycogen decreased 77.2 ± 17.4%, muscle IL-6, IL-8, and MCP-1 mRNA increased 18.5 ± 2.8-, 45.3 ± 7.8-, and 8.25 ± 1.75-fold, and muscle IL-6, IL-8, and MCP-1 protein increased 70...
2016: Frontiers in Physiology
Cristina Caresio, Massimo Salvi, Filippo Molinari, Kristen M Meiburger, Marco Alessandro Minetto
Musculoskeletal ultrasound imaging allows non-invasive measurement of skeletal muscle thickness. Current techniques generally suffer from manual operator dependency, while all the computer-aided approaches are limited to be semi-automatic or specifically optimized for a single muscle. The aim of this study was to develop and validate a fully automatic method, named MUSA (Muscle UltraSound Analysis), for measurement of muscle thickness on longitudinal ultrasound images acquired from different skeletal muscles...
October 6, 2016: Ultrasound in Medicine & Biology
Krzysztof A Tomaszewski, Jens Vikse, Brandon M Henry, Joyeeta Roy, Przemysław A Pękala, Maren Svensen, Daniel Guay, Karolina Saganiak, Jerzy A Walocha
The lateral circumflex femoral artery is responsible for vascularization of the head and neck of the femur, greater trochanter, vastus lateralis and the knee. The origin of the lateral circumflex femoral artery has been reported to vary significantly throughout the literature, with numerous branching patterns described and variable distances to the mid-inguinal point reported. The aim of this study was to determine the estimated population prevalence and pooled means of these anatomical characteristics, and review their associated clinical relevance...
October 7, 2016: Folia Morphologica (Warsz)
Anna Mika, Łukasz Oleksy, Renata Kielnar, Ewa Wodka-Natkaniec, Magdalena Twardowska, Kamil Kamiński, Zbigniew Małek
BACKGROUND: The aim of this study is to assess if the application of different methods of active recovery (working the same or different muscle groups from those which were active during fatiguing exercise) results in significant differences in muscle performance and if the efficiency of the active recovery method is dependent upon the specific sport activity (training loads). DESIGN: A parallel group non-blinded trial with repeated measurements. METHODS: Thirteen mountain canoeists and twelve football players participated in this study...
2016: PloS One
Gabriel Andrade Paz, Jason DeFreitas, Marianna de Freitas Maia, Jurandir Silva, Vicente Lima, Humberto Miranda
STUDY DESIGN: Crossover design. CONTEXT: Excessive valgus and varus force which affected the knee joint during dynamic tasks has been often associated to lower extremity injuries. Strategies to increase the resistance against these asymmetries, such as, the use of a physioball between the knees or elastic bands around the knees are often applied in rehabilitation and conditioning programs. OBJECTIVE: The purpose of this study was to investigate the effect of performing leg press (LP) 45° using a physioball and elastic band over multiple sets with submaximal loads on electromyographic (EMG) amplitude and fatigue indices...
September 26, 2016: Journal of Sport Rehabilitation
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