Read by QxMD icon Read

Muscle power

Jacob J Morse, Gramos Pallaska, Patrick R Pierce, Travis M Fields, Sujay S Galen, Moh H Malek
Morse, JJ, Pallaska, G, Pierce, PR, Fields, TM, Galen, SS, and Malek, MH. Acute low-dose caffeine supplementation increases electromyographic fatigue threshold in healthy men. J Strength Cond Res 30(11): 3236-3241, 2016-The purpose of this study is to determine whether consumption of a single low-dose caffeine drink will delay the onset of the electromyographic fatigue threshold (EMGFT) in the superficial quadriceps femoris muscles. We hypothesize that the EMGFT values for the caffeine condition will be significantly higher than the EMGFT values for the placebo condition...
November 2016: Journal of Strength and Conditioning Research
Justin X Nicoll, Andrew C Fry, Andrew J Galpin, Adam J Sterczala, Donald B Thomason, Christopher A Moore, Lawrence W Weiss, Loren Z F Chiu
PURPOSE: Many physiological maladaptations persist after overreaching and overtraining resistance exercise (RE). However, no studies have investigated changes in mitogen-activated protein kinases (MAPK) after overtraining in humans, despite their critical role regulating exercise-induced muscular adaptations. The purpose of this study was to describe the changes in total and resting phosphorylation status of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase (JNK) and p38-MAPK following a period of RE overreaching or overtraining...
October 22, 2016: European Journal of Applied Physiology
Ellen L Mintz, Juliana A Passipieri, Daniel Y Lovell, George J Christ
Despite the regenerative capacity of skeletal muscle, permanent functional and/or cosmetic deficits (e.g., volumetric muscle loss (VML) resulting from traumatic injury, disease and various congenital, genetic and acquired conditions are quite common. Tissue engineering and regenerative medicine technologies have enormous potential to provide a therapeutic solution. However, utilization of biologically relevant animal models in combination with longitudinal assessments of pertinent functional measures are critical to the development of improved regenerative therapeutics for treatment of VML-like injuries...
October 7, 2016: Journal of Visualized Experiments: JoVE
Wang-Dong Zhang, Wen-Hui Wang, Shu-Xian Li, Shuai Jia, Xue-Feng Zhang, Ting-Ting Cao
BACKGROUND: The neonatal Fc receptor (FcRn) plays a crucial role in transporting IgG and associated antigens across polarized epithelial barriers in mucosal immunity. However, it was not clear that FcRn expression in aggregated lymphoid nodules area (ALNA) in abomasum, a unique and important mucosal immune structure discovered only in Bactrian camels. In the present study, 27 Alashan Bactrian camels were divided into the following five age groups: fetus (10-13 months of gestation), young (1-2 years), pubertal (3-5 years), middle-aged (6-16 years) and old (17-20 years)...
October 20, 2016: BMC Veterinary Research
Eric C Honert, Karl E Zelik
INTRODUCTION: Inverse dynamics joint kinetics are often used to infer contributions from underlying groups of muscle-tendon units (MTUs). However, such interpretations are confounded by multiarticular (multi-joint) musculature, which can cause inverse dynamics to over- or under-estimate net MTU power. Misestimation of MTU power could lead to incorrect scientific conclusions, or to empirical estimates that misguide musculoskeletal simulations, assistive device designs, or clinical interventions...
2016: PloS One
Luca Fusi, Valentina Percario, Elisabetta Brunello, Marco Caremani, Pasquale Bianco, Joseph D Powers, Massimo Reconditi, Vincenzo Lombardi, Gabriella Piazzesi
KEY POINTS: Myosin filament mechanosensing determines the efficiency of the contraction by adapting the number of switched ON motors to the load. Accordingly, the unloaded shortening velocity (V0 ) is already set at the end of the latency relaxation (LR), ∼10 ms after the start of stimulation, when the myosin filament is still in the OFF state. Here the number of actin-attached motors per half-myosin filament (n) during V0 shortening imposed either at the end of LR or at the plateau of the isometric contraction is estimated from the relation between half-sarcomere compliance and force during the force redevelopment after the shortening...
October 20, 2016: Journal of Physiology
Robert Walaszek, Stanislaw Sterkowicz, Wieslaw Chwala, Katarzyna Sterkowicz-Przybycien, Katarzyna Walaszek, Marcin Burdacki, Artur Klys
BACKGROUND: Physical activity is beneficial for young children. The aim is to monitor the changes in body posture and balance, as well as in the level of lower limbs mechanical output in six-year-old boys practicing judo (JU) and in a group not practicing that sport (NT). METHODS: In 12 matched pairs of boys (JU+NT) body mass and height were measured and BMI was calculated at three time points (baseline, three months, six months). Body posture was evaluated with the use of Moiré method (TT, DTK, MR, LALBC-F, DALBS)...
October 20, 2016: Journal of Sports Medicine and Physical Fitness
Mariusz Naczk, Artur Lopacinski, Wioletta Brzenczek-Owczarzak, Jarosław Arlet, Alicja Naczk, Zdzisław Adach
The aim of this study was to evaluate the influence of dry-land inertial training (IT) on muscle force, muscle power, and swimming performance. Fourteen young, national-level, competitive swimmers were randomly divided into IT and control (C) groups. The experiment lasted four weeks, during which time both groups underwent their regular swimming training. In addition, the IT group underwent IT using the Inertial Training Measurement System (ITMS) three times per week. The muscle groups involved during the upsweep phase of the arm stroke in front crawl and butterfly stroke were trained...
October 19, 2016: European Journal of Sport Science
Yoshihiro Fukumoto, Hiroshige Tateuchi, Rui Tsukagoshi, Yusuke Okita, Haruhiko Akiyama, Kazutaka So, Yutaka Kuroda, Noriaki Ichihashi
OBJECTIVE: The aim of this study was to investigate the effects of high-velocity (HV) and low-velocity (LV) resistance training on gait kinematics and kinetics in patients with hip osteoarthritis. DESIGN: This was a single-blind, randomized controlled trial. Forty-six women with hip osteoarthritis were randomly allocated to the HV (n = 23) or LV (n = 23) training group. The participants underwent an 8-week home-based the HV or LV resistance-training program, involving the hip and knee muscles...
October 13, 2016: American Journal of Physical Medicine & Rehabilitation
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
Thomas W Storer, Shehzad Basaria, Tinna Traustadottir, S Mitchell Harman, Karol Pencina, Zhuoying Li, Thomas G Travison, Renee Miciek, Panayiotis Tsitouras, Kathleen Hally, Grace Huang, Shalender Bhasin
CONTEXT: Testosterone's effects on muscle strength and physical function in older men have been inconsistent; its effects on muscle power and fatigability have not been studied. OBJECTIVE: To determine the effects of testosterone administration for 3 years in older men on muscle strength, power, fatigability and physical function Study Design: In this double-blind, placebo-controlled, randomized trial, healthy men ≥60 years with total testosterone 100-400 ng/dL or free testosterone <50 pg/mL, were randomized to 7...
October 18, 2016: Journal of Clinical Endocrinology and Metabolism
Mona Alilet, Julien Behr, Jean-Philippe Nueffer, Benoit Barbier-Brion, Sébastien Aubry
: The subscapularis (SSC) muscle is the most powerful of the rotator cuff muscles, and plays an important role in shoulder motion and stabilization. SSC tendon tear is quite uncommon, compared to the supraspinatus (SSP) tendon, and, most of the time, part of a large rupture of the rotator cuff. Various complementary imaging techniques can be used to obtain an accurate diagnosis of SSC tendon lesions, as well as their extension and muscular impact. Pre-operative diagnosis by imaging is a key issue, since a lesion of the SSC tendon impacts on treatment, surgical approach, and post-operative functional prognosis of rotator cuff injuries...
October 17, 2016: Insights Into Imaging
Angela M Sanford
PURPOSE OF REVIEW: The purpose of this review is to examine the concept of anorexia of aging, including its complex pathophysiology and the multifaceted interventions required to prevent adverse health consequences from this geriatric syndrome. RECENT FINDINGS: Anorexia of aging is extremely common, occurring in up to 30% of elderly individuals; however, this diagnosis is frequently missed or erroneously attributed to a normal part of the aging process. With aging, impairments in smell and taste can limit the desire to eat...
October 5, 2016: Current Opinion in Clinical Nutrition and Metabolic Care
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
Sarah Jones, William D-C Man, Wei Gao, Irene J Higginson, Andrew Wilcock, Matthew Maddocks
BACKGROUND: This review is an update of a previously published review in the Cochrane Database of Systematic Reviews Issue 1, 2013 on Neuromuscular electrical stimulation for muscle weakness in adults with advanced disease.Patients with advanced progressive disease often experience muscle weakness, which can impact adversely on their ability to be independent and their quality of life. In those patients who are unable or unwilling to undertake whole-body exercise, neuromuscular electrical stimulation (NMES) may be an alternative treatment to enhance lower limb muscle strength...
October 17, 2016: Cochrane Database of Systematic Reviews
Thomas Wyss, Maria Boesch, Lilian Roos, Céline Tschopp, Klaus M Frei, Hubert Annen, Roberto La Marca
BACKGROUND: Good physical fitness seems to help the individual to buffer the potential harmful impact of psychosocial stress on somatic and mental health. The aim of the present study is to investigate the role of physical fitness levels on the autonomic nervous system (ANS; i.e. heart rate and salivary alpha amylase) responses to acute psychosocial stress, while controlling for established factors influencing individual stress reactions. METHODS: The Trier Social Stress Test for Groups (TSST-G) was executed with 302 male recruits during their first week of Swiss Army basic training...
December 2016: Sports Medicine—Open
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
R Rabl, A Horvath, C Breitschaedel, S Flunkert, H Roemer, B Hutter-Paier
BACKGROUND: Evaluation of motor deficits in rodents is mostly restricted to limb motor tests that are often high stressors for the animals. NEW METHOD: To test rodents for orofacial motor impairments in a stress-free environment, we established the pasta gnawing test by measuring the biting noise of mice that eat a piece of spaghetti. Two parameters were evaluated, the biting speed and the biting peaks per biting episode. To evaluate the power of this test compared to commonly used limb motor and muscle strength tests, three mouse models of Parkinson's disease, amyotrophic lateral sclerosis and Niemann pick disease were tested in the pasta gnawing test, RotaRod and wire suspension test...
October 13, 2016: Journal of Neuroscience Methods
Morteza Amjadi, Metin Sitti
There is an increasing demand for soft actuators because of their importance in soft robotics, artificial muscles, biomimetic devices, and beyond. However, the development of soft actuators capable of low-voltage operation, powerful actuation, and programmable shape-changing is still challenging. In this work, we propose programmable bilayer actuators that operate based on the large hygroscopic contraction of the copy paper and simultaneously large thermal expansion of the polypropylene film upon increasing the temperature...
October 16, 2016: ACS Nano
Afshin Samani, Divya Srinivasan, Svend Erik Mathiassen, Pascal Madeleine
The spatio-temporal distribution of muscle activity has been suggested to be a determinant of fatigue development. Pursuing this hypothesis, we investigated the pattern of muscular activity in the shoulder and arm during a repetitive dynamic task performed until participants' rating of perceived exertion reached 8 on Borg's CR-10 scale. We collected high-density surface electromyogram (HD-EMG) over the upper trapezius, as well as bipolar EMG from biceps brachii, triceps brachii, deltoideus anterior, serratus anterior, upper and lower trapezius from 21 healthy women...
October 14, 2016: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"