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

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...

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

Does astroglial protein S100B contribute to West Nile neuro-invasive syndrome?

Journal of the neurological sciences·2015

Same author

Variability, frequency composition, and complexity of submaximal isometric knee extension force from subacute to chronic stroke.

Neuroscience·2014

Same author

Persons with reconstructed ACL exhibit altered knee mechanics during high-speed maneuvers.

International journal of sports medicine·2014

Same author

Predictors of oral health after spinal cord injury.

Spinal cord·2013

Same author

Control of Ia afferent input to triceps surae (soleus) locomotor nucleus precedes agonist muscle activation during gait.

Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology·2010

Same author

Re: stem cells in the treatment of chronic spinal cord injury: evaluation of somatosensitive-evoked potentials in 39 patients.

Spinal cord·2010

Search research articles

Related Experiment Video

Updated: May 12, 2026

The Impact of Motor Task Conditions on Goal-Directed Arm Reaching Kinematics and Trunk Compensation in Chronic Stroke Survivors

The Impact of Motor Task Conditions on Goal-Directed Arm Reaching Kinematics and Trunk Compensation in Chronic Stroke Survivors

Published on: May 2, 2021

Impaired force steadiness is associated with changes in force frequency composition in subacute stroke.

J W Chow¹, D S Stokic

¹Center for Neuroscience and Neurological Recovery, Methodist Rehabilitation Center, Jackson, MS 39216, USA. jchow@mmrcrehab.org

|April 4, 2013

Summary

Early stroke impairs force steadiness due to altered force signal frequency. This study found reduced median frequency and increased relative peak power in stroke survivors

More Related Videos

Electroencephalography Network Indices as Biomarkers of Upper Limb Impairment in Chronic Stroke

Electroencephalography Network Indices as Biomarkers of Upper Limb Impairment in Chronic Stroke

Published on: July 14, 2023

Related Experiment Videos

Last Updated: May 12, 2026

The Impact of Motor Task Conditions on Goal-Directed Arm Reaching Kinematics and Trunk Compensation in Chronic Stroke Survivors

The Impact of Motor Task Conditions on Goal-Directed Arm Reaching Kinematics and Trunk Compensation in Chronic Stroke Survivors

Published on: May 2, 2021

Electroencephalography Network Indices as Biomarkers of Upper Limb Impairment in Chronic Stroke

Electroencephalography Network Indices as Biomarkers of Upper Limb Impairment in Chronic Stroke

Published on: July 14, 2023

Area of Science:

Neurology
Rehabilitation Science
Biomedical Engineering

Background:

Force steadiness is crucial for motor control.
Early post-stroke, motor impairments, including force control deficits, are common.
Understanding the neural underpinnings of these deficits is vital for effective rehabilitation.

Purpose of the Study:

To investigate the relationship between force steadiness and the frequency composition of the force signal after stroke.
To determine if early post-stroke force control impairments are linked to changes in force signal spectra.
To explore the correlation between force variability and spectral power in paretic and non-paretic limbs.

Main Methods:

Isometric knee extension tasks at varying contraction levels (10-50% peak torque) were performed by 34 stroke patients and 20 controls.
Power spectrum analysis of the force signal was conducted, measuring median frequency, peak power frequency, and relative power in specific frequency bands (0-3, 4-6, 8-12 Hz).
Force variability was quantified using the coefficient of variation (CV).

Main Results:

Stroke patients exhibited increased force variability (CV) compared to controls.
Paretic and non-paretic legs showed decreased median frequency and increased relative peak power.
The paretic leg displayed increased low-frequency power (0-3 Hz) and decreased higher-frequency power (4-6, 8-12 Hz).
Significant non-linear correlations were found between CV and relative spectral power in the paretic leg and, to a lesser extent, the non-paretic leg.

Conclusions:

Impaired force steadiness early after stroke is associated with altered force signal frequency composition.
Reduced modulation of force spectra and abnormal force variability suggest diminished broadband force output.
These findings highlight potential mechanisms underlying motor control deficits in both affected and unaffected limbs post-stroke.