Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Isotonic and Isometric Muscle Contractions

Isotonic and Isometric Muscle Contractions

Two primary types of muscle contractions are isotonic and isometric, each serving unique functions and involving distinct mechanisms. Both isotonic and isometric contractions are integral to the body's complex system of movement and stability. Isotonic exercises contribute significantly to functional strength and movement, while isometric contractions are crucial for maintaining posture and joint stability.
Isotonic contractions
Isotonic contractions occur when a muscle changes length while the...

Muscle Stimulation Frequency

Muscle Stimulation Frequency

The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...

Motor Unit Stimulation

Motor Unit Stimulation

When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...

Alterations in Muscle Tone ll

Alterations in Muscle Tone ll

Alterations in muscle tone are common manifestations of neurological disorders and reflect dysfunction within different nervous system regions. Spasticity, paratonia, and dystonia represent distinct forms of hypertonia, each with unique mechanisms, clinical features, and diagnostic importance.CharacteristicsSpasticity happens from upper motor neuron lesions and is characterized by velocity-dependent resistance to passive movement. Clinical features include:Exaggerated deep tendon reflexesClonus...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

The effect of age on ankle joint position sense differs between contralateral matching and ipsilateral reproduction tasks.

Experimental brain research·2025

Same author

Fatigability of the thenar muscles using electrical nerve stimulation with fixed stimuli count, while varying the frequency and duty cycle.

Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology·2023

Same author

Does somatosensory feedback from the plantar foot sole contribute to verticality perception?

Somatosensory & motor research·2021

Same author

Posture and gaze tracking of a vertically moving target reveals age-related constraints in visuo-motor coupling.

Neuroscience letters·2017

Same author

Aging affects postural tracking of complex visual motion cues.

Experimental brain research·2016

Same author

Changes in specific jumping performance after detraining period.

The Journal of sports medicine and physical fitness·2014

Search research articles

Related Experiment Video

Updated: May 24, 2026

A Simple Non-invasive Method for Temporary Knockdown of Upper Limb Proprioception

A Simple Non-invasive Method for Temporary Knockdown of Upper Limb Proprioception

Published on: March 3, 2018

Tendon vibration during submaximal isometric strength and postural tasks.

S I Spiliopoulou¹, I G Amiridis, V Hatzitaki

¹Laboratory of Neuromechanics, Department of Physical Education and Sport Sciences, Aristotle University of Thessaloniki at Serres, Agios Ioannis, 62110, Serres, Greece.

European Journal of Applied Physiology

|March 6, 2012

Summary

Tendon vibration (TV) enhances submaximal strength and muscle activation at lower intensities but not maximal efforts. TV also impacts balance control by increasing muscle activity and altering posture, suggesting Ia afferent input influences motor output.

More Related Videos

In Vivo Measurement of Hindlimb Dorsiflexor Isometric Torque from Pig

In Vivo Measurement of Hindlimb Dorsiflexor Isometric Torque from Pig

Published on: September 3, 2021

Related Experiment Videos

Last Updated: May 24, 2026

A Simple Non-invasive Method for Temporary Knockdown of Upper Limb Proprioception

A Simple Non-invasive Method for Temporary Knockdown of Upper Limb Proprioception

Published on: March 3, 2018

In Vivo Measurement of Hindlimb Dorsiflexor Isometric Torque from Pig

In Vivo Measurement of Hindlimb Dorsiflexor Isometric Torque from Pig

Published on: September 3, 2021

Area of Science:

Biomechanics
Neuroscience
Exercise Physiology

Background:

Tendon vibration (TV) is a technique used to stimulate muscle afferents.
Its effects on submaximal strength and balance control require further elucidation.

Purpose of the Study:

To investigate the impact of Achilles tendon vibration on isometric plantarflexion strength and static balance.
To examine the associated changes in muscle activation and motor output.

Main Methods:

29 women performed isometric plantarflexions and postural tasks under various visual and vibration conditions.
Muscle activation (EMG) and torque were measured; ultrasonography assessed muscle contractile properties.

Main Results:

TV increased plantarflexion torque and agonist/antagonist muscle activation at 20% and 30% MVC, but not 10% or 50% MVC.
TV altered center of pressure and increased ankle muscle EMG during balance tasks.
Ultrasonography confirmed TV-induced changes in medial gastrocnemius pennation and fascicle length.

Conclusions:

TV enhances motor output at lower levels of central drive, likely via Ia afferent stimulation.
Motor output augmentation from TV attenuates at higher central drive levels.
TV influences both strength and balance, with distinct effects depending on task intensity and sensory input.