keyword
MENU ▼
Read by QxMD icon Read
search

"Force-velocity"

keyword
https://www.readbyqxmd.com/read/28530478/validity-of-a-linear-velocity-transducer-for-testing-maximum-vertical-jumps
#1
Alejandro Pérez-Castilla, Belén Feriche, Slobodan Jaric, Paulino Padial, Amador García-Ramos
This study aimed to examine the validity of mechanical variables obtained by a linear velocity transducer from the unconstrained and constrained squat jump (SJ). Twenty-three men were tested on the unconstrained SJ and the SJ constrained by a Smith machine. Maximum values of force, velocity, and power were simultaneously recorded both by a linear velocity transducer attached to a bar of mass of 17, 30, 45, 60 and 75 kg and by a force plate. Linear velocity transducer generally overestimated the outcomes measured as compared to the force plate, particularly in unconstrained SJ...
May 22, 2017: Journal of Applied Biomechanics
https://www.readbyqxmd.com/read/28507191/lowering-metabolic-rate-mitigates-muscle-atrophy-in-western-fence-lizards
#2
J Balaban, E Azizi
Extended periods of skeletal muscle disuse can cause a significant loss of contractile proteins, which compromises the ability to generate force, mechanical work or power, thus compromising locomotor performance. Several hibernating organisms can resist muscle atrophy despite months of inactivity. This resistance has been attributed to a reduction in body temperature and metabolic rate and activation of physiological pathways that counteract pathways of protein degradation. However, in these systems such strategies are not mutually exclusive and the effects of these mechanisms can be difficult to separate...
May 15, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28501023/force-velocity-relationship-of-leg-muscles-assessed-with-motorized-treadmill-tests-two-velocity-method
#3
Slobodanka Dobrijevic, Vladimir Ilic, Sasa Djuric, Slobodan Jaric
Linear regression models applied on force (F) and velocity (V) data obtained from loaded multi-joint functional movement tasks have often been used to assess mechanical capacities of the tested muscles. The present study aimed to explore the properties of the F-V relationship of leg muscles exerting the maximum pulling F at a wide range of V on a standard motorized treadmill. Young and physically active male and female subjects (N=13+15) were tested on their maximum pulling F exerted horizontally while walking or running on a treadmill set to 8 different velocities (1...
May 4, 2017: Gait & Posture
https://www.readbyqxmd.com/read/28475551/evaluation-of-muscle-mechanical-capacities-through-the-two-load-method-optimization-of-the-load-selection
#4
Alejandro Pérez-Castilla, Slobodan Jaric, Belén Feriche, Paulino Padial, Amador García-Ramos
Recent research has revealed that the force-velocity relationship obtained from the 'two-load method' (i.e., functional movements tested against just 2 external loads) could be a feasible method for the selective assessment of muscle force, velocity, and power-producing capacities. The study investigated the reliability and concurrent validity of the outcomes of the two-load method observed from (1) farther vs. closer data points (20-70%1RM, 30-60%1RM, and 40-50%1RM), and (2) force-biased (50-70%1RM) vs. velocity-biased (20-40%1RM) data points...
April 25, 2017: Journal of Strength and Conditioning Research
https://www.readbyqxmd.com/read/28469742/muscle-force-velocity-relationships-observed-in-four-different-functional-tests
#5
Milena Z Zivkovic, Sasa Djuric, Ivan Cuk, Dejan Suzovic, Slobodan Jaric
The aims of the present study were to investigate the shape and strength of the force-velocity relationships observed in different functional movement tests and explore the parameters depicting force, velocity and power producing capacities of the tested muscles. Twelve subjects were tested on maximum performance in vertical jumps, cycling, bench press throws, and bench pulls performed against different loads. Thereafter, both the averaged and maximum force and velocity variables recorded from individual trials were used for force-velocity relationship modeling...
February 2017: Journal of Human Kinetics
https://www.readbyqxmd.com/read/28462115/therapeutic-potential-of-eccentric-exercises-for-age-related-muscle-atrophy
#6
REVIEW
Jae-Young Lim
Recent studies have focused on evidence-based interventions to prevent mobility decline and enhance physical performance in older adults. Several modalities, in addition to traditional strengthening programs, have been designed to manage age-related functional decline more effectively. In this study, we reviewed the current relevant literatures to assess the therapeutic potential of eccentric exercises for age-related muscle atrophy (sarcopenia). Age-related changes in human skeletal muscle, and their relationship with physical performance, are discussed with reference to in vitro physiologic and human biomechanics studies...
September 2016: Integr Med Res
https://www.readbyqxmd.com/read/28338423/assessment-of-leg-muscles-mechanical-capacities-which-jump-loading-and-variable-type-provide-the-most-reliable-outcomes
#7
Amador García-Ramos, Belén Feriche, Alejandro Pérez-Castilla, Paulino Padial, Slobodan Jaric
This study aimed to explore the strength of the force-velocity (F-V) relationship of lower limb muscles and the reliability of its parameters (maximum force [F0], slope [a], maximum velocity [V0], and maximum power [P0]). Twenty-three men were tested in two different jump types (squat and countermovement jump: SJ and CMJ), performed under two different loading conditions (free weight and Smith machine: Free and Smith) with 0, 17, 30, 45, 60, and 75 kg loads. The maximum and averaged values of F and V were obtained for the F-V relationship modelling...
July 2017: European Journal of Sport Science
https://www.readbyqxmd.com/read/28328719/predicting-the-maximum-dynamic-strength-in-bench-press-the-high-precision-of-the-bar-velocity-approach
#8
Irineu Loturco, Ronaldo Kobal, José E Moraes, Katia Kitamura, César C Cal Abad, Lucas A Pereira, Fábio Y Nakamura
Loturco, I, Kobal, R, Moraes, JE, Kitamura, K, Cal Abad, CC, Pereira, LA, and Nakamura, FY. Predicting the maximum dynamic strength in bench press: the high precision of the bar velocity approach. J Strength Cond Res 31(4): 1127-1131, 2017-The aim of this study was to determine the force-velocity relationship and test the possibility of determining the 1 repetition maximum (1RM) in "free weight" and Smith machine bench presses. Thirty-six male top-level athletes from 3 different sports were submitted to a standardized 1RM bench press assessment (free weight or Smith machine, in randomized order), following standard procedures encompassing lifts performed at 40-100% of 1RM...
April 2017: Journal of Strength and Conditioning Research
https://www.readbyqxmd.com/read/28282405/in-vivo-muscle-force-and-muscle-power-during-near-maximal-frog-jumps
#9
Eng Kuan Moo, Daniel R Peterson, Timothy R Leonard, Motoshi Kaya, Walter Herzog
Frogs' outstanding jumping ability has been associated with a high power output from the leg extensor muscles. Two main theories have emerged to explain the high power output of the frog leg extensor muscles, either (i) the contractile conditions of all leg extensor muscles are optimized in terms of muscle length and speed of shortening, or (ii) maximal power is achieved through a dynamic catch mechanism that uncouples fibre shortening from the corresponding muscle-tendon unit shortening. As in vivo instantaneous power generation in frog hind limb muscles during jumping has never been measured directly, it is hard to distinguish between the two theories...
2017: PloS One
https://www.readbyqxmd.com/read/28253041/load-force-and-power-velocity-relationships-in-the-prone-pull-up-exercise
#10
Mario Muñoz-López, David Marchante, Miguel A Cano-Ruiz, José López Chicharro, Carlos Balsalobre-Fernández
PURPOSE: To analyze the load, force and power-velocity relationships, as well as to determine the load that optimizes power output on the pull-up exercise. METHODS: Eighty-two resistance trained males (Age = 26.8 ± 5.0 yrs.; Pull-up 1RM - normalized per kg of body mass- = 1.5 ± 0.34) performed two repetitions with 4 incremental loads (ranging 70-100%1-RM) in the pull-up exercise while mean propulsive velocity (MPV), force (MPF) and power (MPP) were measured using a linear transducer...
March 2, 2017: International Journal of Sports Physiology and Performance
https://www.readbyqxmd.com/read/28245549/a-rls-svm-aided-fusion-methodology-for-ins-during-gps-outages
#11
Yiqing Yao, Xiaosu Xu
In order to maintain a relatively high accuracy of navigation performance during global positioning system (GPS) outages, a novel robust least squares support vector machine (LS-SVM)-aided fusion methodology is explored to provide the pseudo-GPS position information for the inertial navigation system (INS). The relationship between the yaw, specific force, velocity, and the position increment is modeled. Rather than share the same weight in the traditional LS-SVM, the proposed algorithm allocates various weights for different data, which makes the system immune to the outliers...
February 24, 2017: Sensors
https://www.readbyqxmd.com/read/28223172/a-simple-model-of-cardiac-muscle-for-multiscale-simulation-passive-mechanics-crossbridge-kinetics-and-calcium-regulation
#12
Fyodor A Syomin, Andrey K Tsaturyan
A simple model of cardiac muscle was designed for multiscale simulation of heart mechanics. Relaxed cardiac muscle was described as a transversally isotropic hyperelastic material. Active tension caused by actin-myosin crossbridges depends on the ensemble averaged strain of myosin heads bound to actin. Calcium activation was modeled by Ca(2+) binding to troponin-C. To account for the dependence of troponin affinity for Ca(2+) on myosin heads strongly bound to actin, the kinetics of troponin binding to Ca(2+) in the overlap zone of the thin and thick filaments and outside it were separated...
February 20, 2017: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/28202584/comparison-of-human-gastrocnemius-forces-predicted-by-hill-type-muscle-models-and-estimated-from-ultrasound-images
#13
Taylor J M Dick, Andrew A Biewener, James M Wakeling
Hill-type models are ubiquitous in the field of biomechanics, providing estimates of a muscle's force as a function of its activation state and its assumed force-length and force-velocity properties. However, despite their routine use, the accuracy with which Hill-type models predict the forces generated by muscles during submaximal, dynamic tasks remains largely unknown. This study compared human gastrocnemius forces predicted by Hill-type models with the forces estimated from ultrasound-based measures of tendon length changes and stiffness during cycling, over a range of loads and cadences...
May 1, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28193897/simulating-the-dynamics-of-the-mechanochemical-cycle-of-myosin-v
#14
Shayantani Mukherjee, Raphael Alhadeff, Arieh Warshel
The detailed dynamics of the cycle of myosin-V are explored by simulation approaches, examining the nature of the energy-driven motion. Our study started with Langevin dynamics (LD) simulations on a very coarse landscape with a single rate-limiting barrier and reproduced the stall force and the hand-over-hand dynamics. We then considered a more realistic landscape and used time-dependent Monte Carlo (MC) simulations that allowed trajectories long enough to reproduce the force/velocity characteristic sigmoidal correlation, while also reproducing the hand-over-hand motion...
February 28, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28188199/back-to-the-future-revisiting-the-physiological-cost-of-negative-work-as-a-team-based-activity-for-exercise-physiology-students
#15
Matthew A Kilgas, Steven J Elmer
We implemented a team-based activity in our exercise physiology teaching laboratory that was inspired from Abbott et al.'s classic 1952 Journal of Physiology paper titled "The physiological cost of negative work." Abbott et al. connected two bicycles via one chain. One person cycled forward (muscle shortening contractions, positive work) while the other resisted the reverse moving pedals (muscle lengthening contractions, negative work), and the cost of work was compared. This study was the first to link human whole body energetics with isolated muscle force-velocity characteristics...
March 1, 2017: Advances in Physiology Education
https://www.readbyqxmd.com/read/28169153/effects-of-light-load-maximal-lifting-velocity-weight-training-vs-combined-weight-training-and-plyometrics-on-sprint-vertical-jump-and-strength-performance-in-adult-soccer-players
#16
David Rodríguez-Rosell, Julio Torres-Torrelo, Felipe Franco-Márquez, José Manuel González-Suárez, Juan José González-Badillo
OBJECTIVES: The purpose of this study was to compare the effects of combined light-load maximal lifting velocity weight training (WT) and plyometric training (PT) with WT alone on strength, jump and sprint performance in semiprofessional soccer players. DESIGN: Experimental, pre-post tests measures. METHODS: Thirty adult soccer players were randomly assigned into three groups: WT alone (FSG, n=10), WT combined to jump and sprint exercises (COM, n=10) and control group (CG, n=10)...
January 24, 2017: Journal of Science and Medicine in Sport
https://www.readbyqxmd.com/read/28162847/c-tactile-afferents-cutaneous-mediators-of-oxytocin-release-during-affiliative-tactile-interactions
#17
REVIEW
Susannah C Walker, Paula D Trotter, William T Swaney, Andrew Marshall, Francis P Mcglone
Low intensity, non-noxious, stimulation of cutaneous somatosensory nerves has been shown to trigger oxytocin release and is associated with increased social motivation, plus reduced physiological and behavioural reactivity to stressors. However, to date, little attention has been paid to the specific nature of the mechanosensory nerves which mediate these effects. In recent years, the neuroscientific study of human skin nerves (microneurography studies on single peripheral nerve fibres) has led to the identification and characterisation of a class of touch sensitive nerve fibres named C-tactile afferents...
January 19, 2017: Neuropeptides
https://www.readbyqxmd.com/read/28062031/how-to-measure-load-dependent-kinetics-of-individual-motor-molecules-without-a-force-clamp
#18
J Sung, K I Mortensen, J A Spudich, H Flyvbjerg
Single-molecule force spectroscopy techniques, including optical trapping, magnetic trapping, and atomic force microscopy, have provided unprecedented opportunities to understand biological processes at the smallest biological length scales. For example, they have been used to elucidate the molecular basis of muscle contraction and intracellular cargo transport along cytoskeletal filamentous proteins. Optical trapping is among the most sophisticated single-molecule techniques. With exceptionally high spatial and temporal resolutions, it has been extensively utilized to understand biological functions at the single molecule level, such as conformational changes and force-generation of individual motor proteins or force-dependent kinetics in molecular interactions...
2017: Methods in Enzymology
https://www.readbyqxmd.com/read/28051333/optimal-loading-for-maximising-power-during-sled-resisted-sprinting
#19
Matt R Cross, Matt Brughelli, Pierre Samozino, Scott R Brown, Jean-Benoit Morin
Purpose We sought to ascertain whether force-velocity-power relationships could be compiled from a battery of sled-resisted over-ground sprints, and to clarify and compare the optimal loading conditions for maximising power production for different athlete cohorts. Methods Recreational mixed-sport athletes (n=12) and sprinters (n=15) performed multiple trials of maximal sprints unloaded and towing a selection of sled masses (20-120% body-mass). Velocity data were collected by sports radar, and kinetics at peak velocity were quantified using friction coefficients and aerodynamic drag...
January 4, 2017: International Journal of Sports Physiology and Performance
https://www.readbyqxmd.com/read/28044199/muscle-fascicle-shortening-behaviour-of-vastus-lateralis-during-a-maximal-force-velocity-test
#20
Hugo Hauraix, Sylvain Dorel, Giuseppe Rabita, Gaël Guilhem, Antoine Nordez
PURPOSE: Muscle fascicles-tendon interactions are the main determinant in production of high joint velocity. Currently, no study has investigated the muscle fascicles behaviour of knee extensor muscles until the highest reachable velocity (e.g., unloaded knee extension). We aimed to track the changes in vastus lateralis fascicles length during knee extensions to quantify muscle fascicles and tendinous tissues contributions to muscle-tendon unit shortening and to determine maximal muscle fascicles shortening velocity...
February 2017: European Journal of Applied Physiology
keyword
keyword
80523
1
2
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"