Voluntary contractionIsometricExcitation-contractionMaximalEvoked PotentialsElectromyographyMethodsEccentricTissueNerveNeuralFatigue taskHighRelationshipsActivationKeywordsForceEffectsEffectNeuromodulationPhysiologicalVivoIntactDepressionCurrentsApproachesMeasurementsForce productionSlow-twitchPropertiesCurrentGenerallyRelationship
Voluntary contraction3
- Stimulation intensity was set to achieve 15% of knee extension maximal voluntary contraction (MVC). (wku.edu)
- In order to determine which types of fatigue protocols are most likely to induce LFF, ten individuals participated in four different fatigue experiments which induced similar reductions in maximal force output as following: (1) 2-min intermittent high-frequency stimulation (40 Hz), (2) 4-min intermittent low-frequency stimulation (20 Hz), (3) sustained 100% maximal voluntary contraction (MVC), and (4) low-force voluntary contractions (20% MVC). (nih.gov)
- However, these studies did not test H-reflex modulation during isometric maximum voluntary contraction (iMVC) and did not incorporate a control group in their study design to compare the results of the endurance training group to individuals without the endurance training stimulus. (frontiersin.org)
Isometric8
- The effect of number of lengthening contractions on rat isometric force production at different frequencies of nerve stimulation. (cdc.gov)
- Aim: To test the effect of 3, 10, 60 and 240 lengthening contractions (LC) on maximal isometric force of rat plantar flexor muscles at different stimulation frequencies. (cdc.gov)
- After the lengthening contraction protocols, maximal isometric force was measured at different frequencies of nerve activation to obtain frequency-dependent force deficits (weakness). (cdc.gov)
- Using a ratio of isometric force at 20:100 Hz stimulation, the relative depression of force at low frequency was determined. (cdc.gov)
- The relative depression of isometric force at low frequency was most prominent during the early repetitions. (cdc.gov)
- All subjects performed maximal voluntary contractions (MVC) and an intermittent knee extension isometric submaximal voluntary fatigue task at 50% MVC until the fatigue criteria were met for pre-post testing. (wku.edu)
- Measured time courses of force decay during isometric contractions of rabbit M. gastrocnemius and M. plantaris were employed for model verification, with the finding that our suggested model enhancement proved eminently promising. (frontiersin.org)
- During neuromuscular testing, rate of torque development, isometric maximum voluntary torque and muscle activation were measured. (frontiersin.org)
Excitation-contraction2
- Conclusion: As low-frequency force depression appears to result primarily from excitation-contraction (E-C) coupling failure, the early LC in a series of repeated contractions probably contribute most to damage of the cellular components involved in E-C coupling. (cdc.gov)
- Written in terms of differential-algebraic equations, the new sub-model allows to enhance existing Hill-type excitation-contraction models in a straightforward way. (frontiersin.org)
Maximal1
- The degree of LFF during the low-force voluntary contractions was most highly correlated to the duration of the fatigue task and to a lesser extent, to the decrease in maximal force output and the force-time integrals during the fatigue task. (nih.gov)
Evoked Potentials1
- These evoked potentials are elicited by electrical stimulation of the posterior tibial nerve in the popliteal fossa and their amplitudes can be recorded in the soleus muscle (SOL). (frontiersin.org)
Electromyography1
- Surface electromyography (sEMG) of the vastus lateralis (VL) and vastus medialis (VM) muscles were recorded during the fatigue task to examine changes in muscle activation. (wku.edu)
Methods1
Eccentric1
- Eccentric muscle actions (ECC) are characterized by muscle lengthening, despite actin-myosin crossbridge formation. (researchgate.net)
Tissue1
- electrical currents are slightly slowed down at cells' membranes which causes an increase of capacitive tissue properties. (answerdiaries.co.uk)
Nerve1
- Furthermore, evoked spinal reflex responses of the soleus muscle (H-reflex evoked at rest and during iMVC, V-wave), peak twitch torques induced by electrical stimulation of the posterior tibial nerve at rest and fatigue resistance were evaluated. (frontiersin.org)
Neural2
- Initiated by neural impulses and subsequent calcium release, skeletal muscle fibers contract (actively generate force) as a result of repetitive power strokes of acto-myosin cross-bridges. (frontiersin.org)
- Commonly, muscle fatigue, i.e., the decline of the generable force level over time, is differentiated between central fatigue , i.e., the inability of the neural network to provide sufficient stimulation, and peripheral fatigue , i.e., the inability of the muscle cells to provide energy through metabolic activities (cf. (frontiersin.org)
Fatigue task1
- EMG data were quantified for root mean square (RMS) EMG and reported as a percent rate of change over the duration of the fatigue task and median frequency (MF) is reported as the average MF during the fatigue task. (wku.edu)
High8
- Neuromuscular electrical stimulation (NMES) is often used as a rehabilitative modality and evidence has suggested that high frequencies of NMES may elicit increases in muscle strength. (wku.edu)
- However, little is known regarding the effects of a high-frequency NMES intervention on voluntary skeletal muscle fatigue. (wku.edu)
- The aim of this study was to determine the effect of a 4-week high-frequency NMES intervention on voluntary muscular fatigue and changes in neuromuscular activation patterns of the quadriceps during voluntary fatiguing muscle contractions in older adults. (wku.edu)
- Treatment with high-frequency NMES did not improve muscle endurance or related EMG parameters. (wku.edu)
- It is possible that NMES induced adaptations may be frequency-specific and that high-frequency NMES may not be efficacious when the goal is to improve skeletal muscle endurance. (wku.edu)
- Low-frequency fatigue (LFF) is defined as a greater loss of force that occurs in during low versus high frequencies of stimulation. (nih.gov)
- LFF was higher following the low-force voluntary contractions compared to the high-force voluntary and evoked contractions. (nih.gov)
- Muscles performing mechanical work become exhausted, that is, they fail to maintain high force levels for a longer time period. (frontiersin.org)
Relationships1
- Short (5s) trains of 10, 20, 30, 40, and 80 Hz were used to determine the force-versus-frequency relationships before and after the fatigue tasks. (nih.gov)
Activation1
- Triceps surae muscle activation and tibialis anterior muscle co-activation were assessed by normalized root mean square of the EMG signal during the initial phase of contraction (0-100, 100-200 ms) and iMVC of the plantar flexors. (frontiersin.org)
Keywords1
- Keywords: electrical impedance tomography and bioimpedance. (answerdiaries.co.uk)
Force2
- Force deficits were also measured at each stimulation frequency tested (5:120 Hz). (cdc.gov)
- Muscles acting eccentrically are capable of producing higher levels of force compared to muscles acting concentrically. (researchgate.net)
Effects1
- Therefore, the effects which determine the tissue's impedance depend on the stimulation frequency. (answerdiaries.co.uk)
Effect1
- Previously published studies on the effect of short-term endurance training on neuromuscular function of the plantar flexors have shown that the H-reflex elicited at rest and during weak voluntary contractions was increased following the training regime. (frontiersin.org)
Neuromodulation2
- Transcranial magnetic stimulation is a neuromodulation technique increasingly used to partly fill this therapeutic void. (solacepsychiatry.com)
- In terms of alternative treatment approaches, one option is therapeutic neuromodulation, which involves the use of various devices to alter electrical activity in the central nervous system. (solacepsychiatry.com)
Physiological1
- Furthermore, the physiological and psychological effects of higher frequency sound and noise comprise an enormous volume of literature and have not been reviewed at this time. (nih.gov)
Vivo3
- The aim of this study was to investigate the effects of short-term nitrate supplementation on the in vivo contractile properties of the skeletal muscle and voluntary muscle function of humans. (medscape.com)
- Conclusions These results indicate that 7 d of dietary nitrate supplementation enhanced the in vivo contractile properties of the human skeletal muscle. (medscape.com)
- The zebrafish Danio rerio offers many advantages for investigating the relationship between ion channel expression and muscle fibre activity in vivo . (silverchair.com)
Intact2
- Methods: Using a dynamometer and electrical nerve stimulation, maximally active skeletal muscles were stretched by ankle rotation to produce LC of the plantar flexor muscles in intact female rats. (cdc.gov)
- [ 14 ] Intact fast-twitch, but not slow-twitch muscle, of nitrate-fed mice had 50%-100% greater peak force response to low frequencies (≤50 Hz) of electrical stimulation compared with age-matched controls, and this effect seemed to be due to improved intracellular calcium handling and increased crossbridge sensitivity to calcium. (medscape.com)
Depression3
- Conclusion: As low-frequency force depression appears to result primarily from excitation-contraction (E-C) coupling failure, the early LC in a series of repeated contractions probably contribute most to damage of the cellular components involved in E-C coupling. (cdc.gov)
- In the context of treating depression, we critically review the development of transcranial magnetic stimulation, focusing on the results of controlled and pragmatic trials for depression, which consider its efficacy, safety, and tolerability. (solacepsychiatry.com)
- Two such options presently cleared by the US Food and Drug Administration (FDA) for the treatment of depression are vagus nerve stimulation (VNS) and transcranial magnetic stimulation (TMS). (solacepsychiatry.com)
Currents5
- The steady-state and kinetic properties of Na + and K + currents of inner (white) and outer (red) muscles of zebrafish larvae 4-6 days post-fertilization (d.p.f.) are described. (silverchair.com)
- In inner muscle, the outward currents were half-activated at -1.0 mV and half-inactivated at-30.4 mV, and completely inactivated within 100 ms of depolarization. (silverchair.com)
- However, spiking at frequencies of up to 200 cycles s -1 was evoked by the injection of depolarizing pulses separated by short hyperpolarizing currents. (silverchair.com)
- We suggest that the properties of the inward sodium and outward potassium currents permit high frequency firing in response to a pulsatile depolarizing input of the kind expected in fast swimming, whilst safeguarding against tetany during a strong depolarization. (silverchair.com)
- Interferential current is another form system causes increases in heart rate, of sensory electrostimulation, is formed peripheral vascular resistance and venous from two different medium-frequency return to the heart, favoring an increase in currents, which interfere with each other, blood pressure2. (bvsalud.org)
Approaches1
- In the absence of a clearly superior strategy, approaches employing vibrotactile, electrotactile and skin-stretch stimulation achieved better and more consistent results, considering both kinesthetic and grip force information, compared with other strategies or any incidental feedback. (biomedcentral.com)
Measurements2
- Measurements of extremely low frequency (ELF) magnetic fields ranged from 0.1 to 2100 milligauss (mG) and measurements of very low frequency (VLF) fields ranged from 0.1 to 30 mG. (cdc.gov)
- Measurements of ELF electric fields ranged from 2 to 5.8 volts per meter (V/m) and VLF fields ranged from 1.8 to 300 V/m. (cdc.gov)
Force production2
- Specifically, nitrate supplementation improved excitation-contraction coupling at low frequencies of stimulation and enhanced evoked explosive force production but did not affect maximum or explosive voluntary force production in untrained individuals. (medscape.com)
- 50 Hz) was similar between nitrate and control mice, rapid (explosive) force production of fast-twitch muscle was markedly enhanced in the early rising phase of 100-Hz tetanic contraction (35% reduction in the time to reach 50% peak force). (medscape.com)
Slow-twitch1
- An inactivating, outward K + current exists in both rat and frog skeletal fibres, while a noninactivating outward K + current is associated with rat slow-twitch muscle (Duval and Leoty, 1980a , b ). (silverchair.com)
Properties1
- Purpose Dietary nitrate supplementation positively affects cardiovascular function at rest and energy metabolism during exercise in humans and has recently also been reported to markedly enhance the in vitro contractile properties of mouse fast-twitch muscle. (medscape.com)
Current3
- In inner muscle fibres, all tested levels of depolarizing current above a threshold value evoked only one action potential. (silverchair.com)
- The autonomic imbalance, amplitude-modulated frequency (100Hz characterized by the hyperactive and 5Hz) of interferential current applied in sympathetic system and the hypoactive the paravertebral region modify the vessel parasympathetic system, is associated with diameter and blood flow of healthy cardiovascular diseases, such as volunteers15, which suggests a therapeutic hypertension and heart failure3. (bvsalud.org)
- BIA works by measuring how difficult it is for a harmless electrical current to move through the body. (serenitychiro.com)
Generally1
- These kinds of exercises generally involve large muscle groups and foster a strong and healthy heart and lung function. (serenitychiro.com)
Relationship1
- As yet, no firm conclusions have been reached regarding the relationship between this low-frequency noise and the residents' health complaints. (nih.gov)