Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Ankle Joint01:10

Ankle Joint

3.7K
The ankle is formed by the talocrural joint (crural = leg). It consists of the articulations between the talus bone of the foot and the distal ends of the tibia and fibula of the leg. The superior aspect of the talus bone is square-shaped and has three areas of articulation. The top of the talus articulates with the inferior tibia. This is the portion of the ankle joint that carries the body weight between the leg and foot. The sides of the talus are firmly held in position by the articulations...
3.7K
Muscles of the Leg that Move the Foot and Toes01:28

Muscles of the Leg that Move the Foot and Toes

4.9K
The human leg comprises an intricate system of muscles that facilitate the movement of feet and toes. Within this system, the muscles are categorized into the anterior, lateral, and posterior compartments, each with a unique set of muscles carrying out specific functions.
Anterior Compartment
The anterior compartment includes muscles that contribute to the dorsiflexion of the foot. This compartment houses the tibialis anterior, extensor hallucis longus, and extensor digitorum longus muscles....
4.9K
Somatic Spinal Reflexes01:22

Somatic Spinal Reflexes

7.9K
Somatic spinal reflexes are rapid, involuntary muscular responses to external stimuli that involve the somatic musculature and the spinal cord.
One of the most well-known somatic spinal reflexes is the stretch reflex, which is activated by the sudden stretching of a muscle. This reflex involves the activation of specialized sensory receptors called muscle spindles, which are located in the muscle tissue and detect changes in the length and speed of muscle contractions. When a muscle is suddenly...
7.9K
Motor Unit Stimulation01:20

Motor Unit Stimulation

4.9K
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...
4.9K
Reflex Activity01:08

Reflex Activity

5.0K
A reflex activity is an automatic, involuntary response to specific stimuli. It is a part of our survival mechanism, designed to protect us from potential harm. For example, when a bright light suddenly shines into our eyes, we instinctively close them or look away. This is a simple reflex activity orchestrated by the nervous system without conscious thought or effort.
A reflex exam is a diagnostic procedure performed by a healthcare professional to evaluate the functionality of a patient's...
5.0K
Muscle Stimulation Frequency01:22

Muscle Stimulation Frequency

5.1K
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...
5.1K

You might also read

Related Articles

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

Sort by
Same author

Treatment Patterns and Clinical Outcomes in Patients With EGFR-Mutated Non-Small-Cell Lung Cancer After Progression on Osimertinib.

Clinical lung cancer·2024
Same author

Overcoming Barriers to Tobacco Cessation and Lung Cancer Screening among Racial and Ethnic Minority Groups and Underserved Patients in Academic Centers and Community Network Sites: The City of Hope Experience.

Journal of clinical medicine·2023
Same author

Increasing clinician participation in tobacco cessation by an implementation science-based tobacco cessation champion program.

Cancer causes & control : CCC·2022
Same author

Ablative Radiotherapy as a Strategy to Overcome TKI Resistance in EGFR-Mutated NSCLC.

Cancers·2022
Same author

Cancer Survivors, Oncology, and Primary Care Perspectives on Survivorship Care: An Integrative Review.

Journal of primary care & community health·2022
Same author

Machine learning to refine prognostic and predictive nodal burden thresholds for post-operative radiotherapy in completely resected stage III-N2 non-small cell lung cancer.

Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology·2022
Same journal

A Biologically Dominant Trophoblastic Component Guiding Neoadjuvant EMA/CO in Endometrial Carcinoma: A Clinical Case Report.

Clinical case reports·2026
Same journal

Could Fabry Disease Cause Giant Coronary Aneurysms in a 7-Month-Old Infant: A Case Report.

Clinical case reports·2026
Same journal

Correction to "Loss of Consciousness in a Child Following Accidental Ingestion of Brimonidine Ointment: A Case Report".

Clinical case reports·2026
Same journal

Simultaneous Transvenous Lead Extraction and Intra-Operative Epicardial Extravascular Defibrillator (EV-ICD) Implantation During Tricuspid Valve Replacement.

Clinical case reports·2026
Same journal

Successful Surgical Management of Chronic Subdural Hematoma in a Patient With Severe Thrombocytopenia due to Aplastic Anemia: A Case Report.

Clinical case reports·2026
Same journal

Appendix Mucinous Neoplasm.

Clinical case reports·2026
See all related articles

Related Experiment Video

Updated: Apr 6, 2026

Diagnosis of Musculus Gastrocnemius Tightness - Key Factors for the Clinical Examination
08:43

Diagnosis of Musculus Gastrocnemius Tightness - Key Factors for the Clinical Examination

Published on: July 7, 2016

15.2K

Ankle clonus.

Shoaib Bilal Fareedy1, Ranjan Pathak1

  • 1Department of Medicine, Reading Health System Reading, PA, USA.

Clinical Case Reports
|July 18, 2015
PubMed
Summary
This summary is machine-generated.

Clonus, involuntary muscle contractions, can result from neurological damage like stroke. This case highlights significant left ankle clonus in a patient with a history of right middle cerebral artery stroke.

Keywords:
Ankle clonusclonusstrokevideo case

More Related Videos

In Vivo Measurement of Hindlimb Dorsiflexor Isometric Torque from Pig
09:41

In Vivo Measurement of Hindlimb Dorsiflexor Isometric Torque from Pig

Published on: September 3, 2021

4.6K
Author Spotlight: Integrating Mechanical and Biological Analysis in Tendinopathy Research
04:37

Author Spotlight: Integrating Mechanical and Biological Analysis in Tendinopathy Research

Published on: March 1, 2024

1.5K

Related Experiment Videos

Last Updated: Apr 6, 2026

Diagnosis of Musculus Gastrocnemius Tightness - Key Factors for the Clinical Examination
08:43

Diagnosis of Musculus Gastrocnemius Tightness - Key Factors for the Clinical Examination

Published on: July 7, 2016

15.2K
In Vivo Measurement of Hindlimb Dorsiflexor Isometric Torque from Pig
09:41

In Vivo Measurement of Hindlimb Dorsiflexor Isometric Torque from Pig

Published on: September 3, 2021

4.6K
Author Spotlight: Integrating Mechanical and Biological Analysis in Tendinopathy Research
04:37

Author Spotlight: Integrating Mechanical and Biological Analysis in Tendinopathy Research

Published on: March 1, 2024

1.5K

Area of Science:

  • Neurology
  • Neuroscience
  • Clinical Medicine

Background:

  • Clonus is characterized by involuntary, rhythmic muscular contractions and relaxations.
  • It often indicates upper motor neuron pathway damage.
  • Potential causes include stroke, multiple sclerosis, and metabolic conditions like hepatic failure or serotonin syndrome.

Purpose of the Study:

  • To present a video case study of clonus.
  • To illustrate clonus in the context of a specific neurological event.

Main Methods:

  • Case report presentation.
  • Video recording of clinical signs.

Main Results:

  • Demonstration of pronounced left ankle clonus.
  • The patient had a history of right middle cerebral artery stroke.

Conclusions:

  • This case underscores the link between cerebrovascular events and the manifestation of clonus.
  • Visual documentation of clonus provides valuable insight for medical education and understanding.