Estimation of force-activation, force-length, and force-velocity properties in isolated, electrically stimulated muscle

1994 ◽  
Vol 41 (3) ◽  
pp. 205-216 ◽  
Author(s):  
W.K. Durfee ◽  
K.I. Palmer
Keyword(s):  
Force Velocity ◽  
Activation Force ◽  
Force Activation

Force responses to constant-velocity shortening of electrically stimulated human muscle-tendon complex

1996 ◽  
Vol 81 (1) ◽  
pp. 384-392 ◽  
Author(s):  
C. S. Cook ◽  
M. J. McDonagh
Keyword(s):  
Isometric Force ◽  
Human Muscle ◽  
Maximal Activation ◽  
First Dorsal Interosseus ◽  
In Series ◽  
Velocity Equation ◽  
Force Velocity ◽  
Activation Force ◽  
The Hill ◽  
Different Levels

Force-velocity curves in human muscle often have unexpectedly high forces at high velocities. If series elasticity is the cause, it should have less effect at lower activation levels and larger shortening amplitudes. The first dorsal interosseus muscle-tendon complex was shortened at different levels of activation and by different amplitudes. Force-velocity curves had high force well maintained at high velocities. With an actuator release of 4.21 mm at 80% of maximal activation, force was > 45% of isometric force (Po) for all actuator velocities > 200 mm/s (1.49 muscle lengths/s). At 30% activation, the force was > 25% of Po at these velocities. The smaller 2.46-mm releases produced higher forces than the 4.21-mm releases at these velocities. At 80% activation, force was > 65% of Po, and at 30% activation, it was > 50% of Po at these velocities. Corrections of these data for elasticity produced classic Hill-type force-velocity curves. A model incorporating the Hill force-velocity equation and a spring in series accounts for the results.

scholarly journals Effects of plantar flexors training (force vs. velocity) on plantar flexion and squat jump force-velocity relationships

2019 ◽  
Vol 22 (sup1) ◽  
pp. S350-S351
Author(s):  
C. Giroux ◽  
R. Hager ◽  
J. Feugray ◽  
G. Lauby ◽  
S. Dorel ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
Plantar Flexors ◽  
Squat Jump ◽  
Force Velocity

scholarly journals Eccentric Force-Velocity Characteristics during a Novel Squat Protocol in Trained Rugby Union Athletes—Pilot Study

2021 ◽  
Vol 6 (2) ◽  
pp. 32
Author(s):  
Conor McNeill ◽  
C. Martyn Beaven ◽  
Daniel T. McMaster ◽  
Nicholas Gill
Keyword(s):  
Pilot Study ◽  
Dynamic Performance ◽  
Intraclass Correlation ◽  
Rugby Union ◽  
Mean Velocity ◽  
Force Development ◽  
Back Squat ◽  
Force Velocity ◽  
Force Time ◽  
Change In Mean

Eccentric strength characteristics have been shown to be important factors in physical performance. Many eccentric tests have been performed in isolation or with supramaximal loading. The purpose of this study was to investigate within- and between- session reliability of an incremental eccentric back squat protocol. Force plates and a linear position transducer captured force-time-displacement data across six loading conditions, separated by at least seven days. The reliability of eccentric specific measurements was assessed using coefficient of variation (CV), change in mean, and intraclass correlation coefficient (ICC). Eccentric peak force demonstrated good ICC (≥0.82) and TE (≤7.3%) for each load. Variables based on mean data were generally less reliable (e.g., mean rate of force development, mean force, mean velocity). This novel protocol meets acceptable levels of reliability for different eccentric-specific measurements although the extent to which these variables affect dynamic performance requires further research.

scholarly journals Maximizing Acceleration and Change of Direction in Sport: A Case Series to Illustrate How the Force-Velocity Profile Provides Additional Information to That Derived from Linear Sprint Time

2021 ◽  
Vol 18 (11) ◽  
pp. 6140
Author(s):  
Andrés Baena-Raya ◽  
Manuel A. Rodríguez-Pérez ◽  
Pedro Jiménez-Reyes ◽  
Alberto Soriano-Maldonado
Keyword(s):  
Mechanical Properties ◽  
Case Series ◽  
Relevant Information ◽  
Maximal Power Output ◽  
Sprint Time ◽  
Change Of Direction ◽  
Training Interventions ◽  
Additional Information ◽  
Technical Report ◽  
Force Velocity

Sprint running and change of direction (COD) present similar mechanical demands, involving an acceleration phase in which athletes need to produce and apply substantial horizontal external force. Assessing the mechanical properties underpinning individual sprint acceleration might add relevant information about COD performance in addition to that obtained through sprint time alone. The present technical report uses a case series of three athletes with nearly identical 20 m sprint times but with different mechanical properties and COD performances. This makes it possible to illustrate, for the first time, a potential rationale for why the sprint force-velocity (FV) profile (i.e., theoretical maximal force (F0), velocity (V0), maximal power output (Pmax), ratio of effective horizontal component (RFpeak) and index of force application technique (DRF)) provides key information about COD performance (i.e., further to that derived from simple sprint time), which can be used to individualize training. This technical report provides practitioners with a justification to assess the FV profile in addition to sprint time when the aim is to enhance sprint acceleration and COD performance; practical interpretations and advice on how training interventions could be individualized based on the athletes’ differential sprint mechanical properties are also specified.

Anodal transcranial direct current stimulation enhances strength training volume but not the force–velocity profile

2020 ◽  
Vol 120 (8) ◽  
pp. 1881-1891 ◽  
Author(s):  
Carlos Alix-Fages ◽  
Amador García-Ramos ◽  
Giancarlo Calderón-Nadal ◽  
David Colomer-Poveda ◽  
Salvador Romero-Arenas ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Strength Training ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Training Volume ◽  
Direct Current Stimulation ◽  
Force Velocity

The High-Pull Exercise: A Comparison Between a VersaPulley Flywheel Device and the Free Weight

2017 ◽  
Vol 12 (4) ◽  
pp. 527-532 ◽  
Author(s):  
F. Javier Núñez ◽  
Luis J. Suarez-Arrones ◽  
Paul Cater ◽  
Alberto Mendez-Villanueva
Keyword(s):  
Blood Lactate ◽  
Peak Velocity ◽  
Lactate Concentration ◽  
Training Session ◽  
Blood Lactate Concentration ◽  
Free Weight ◽  
Force Velocity ◽  
S Peak ◽  
Rugby Players ◽  
Eccentric Overload

The aim of this study was to examine the kinematics and kinetics (force, velocity, and acceleration) and blood lactate concentration with the VersaPulley (VP) device in comparison with free-weight (FW) exercise at a similar external load. Fifteen rugby players randomly performed 2 training sessions of 6 sets of 6 repetitions with 20 s of recovery between sets of the high-pull exercise with the VP and the FW. The training sessions were separated by 72 h. Barbell displacement (cm), peak velocity (m/s), peak acceleration (m/s2), mean propulsive velocity (m/s), mean propulsive acceleration (m/s2), propulsive phase (%), and mean and maximal force (N) were continuously recorded during each repetition. Blood lactate concentration was measured after each training session (end) and 3 min and 5 min later. Barbell displacement (+4.8%, small ES), peak velocity (+4.5% small ES), mean propulsive acceleration (+8.8%, small ES), and eccentric force (+26.7, large ES) were substantially higher with VP than with FW. Blood lactate concentration was also greater after the VP exercise (end +32.9%, 3 min later +36%, 5 min later +33.8%; large ES). Maximal concentric force was substantially higher with FW than VP during the 6th set (+6.4%, small ES). In the cohort and exercise investigated in the current study, VP training can be considered an efficient training device to induce an accentuated eccentric overload and augmented metabolic demands (ie, blood lactate concentration).

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