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

Motor Unit Stimulation01:20

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...
Design Example: Frog Muscle Response01:14

Design Example: Frog Muscle Response

A student is tasked to work on an intriguing experiment involving an RL (Resistor-Inductor) circuit to study the muscle response of a frog's leg to electrical stimulation. The RL circuit plays a crucial role in this experiment, providing the means to control and measure the electrical impulses that trigger muscle contraction.
When the switch connecting the RL circuit is closed, a brief muscle contraction is observed. This is because, at a steady state, the inductor acts like a short circuit,...
Exercise and Muscle Performance01:27

Exercise and Muscle Performance

Exercise induces a range of adaptations in muscle tissue, depending on the type and duration of activity. Such physical training can be broadly categorized into two types: endurance exercises and resistance exercises.
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
Muscle Stimulation Frequency01:22

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...
Excitation-Contraction Coupling in Skeletal Muscles01:20

Excitation-Contraction Coupling in Skeletal Muscles

Excitation-contraction coupling is a series of events that occur between generating an action potential and initiating a muscle contraction. It occurs at the triad, a structure found in skeletal muscle fibers that comprise a T-tubule and terminal cisternae of the sarcoplasmic reticulum on each side. These triads are visible in longitudinally sectioned muscle fibers. They are typically located at the A-I junction — the junction between the A and I bands of the sarcomere.
When an action potential...
Generation of Action Potential in Skeletal Muscles01:24

Generation of Action Potential in Skeletal Muscles

Every cell in the body maintains a membrane potential due to an uneven distribution of positive and negative charges across its plasma membrane. The membrane potential is measured in millivolts and quantifies the difference in charge across the membrane.
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the cell's...

You might also read

Related Articles

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

Sort by
Same author

Normative data and predictors of trunk muscle endurance performance in young tennis players.

Frontiers in sports and active living·2026
Same author

Grip Strength in Young Tennis Players: Normative Values and Predictors of Performance.

International journal of sports physiology and performance·2026
Same author

Spatial distribution of major and trace elements in artificial lakes in Serbia: health risk indices and suitability of water for drinking and irrigation purposes.

Environmental monitoring and assessment·2023
Same author

Backheel Pass During Forward Running as a Mechanism of Severe Acute Hamstring Injury in Football: A Case Report.

Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine·2023
Same author

Effects of age, sex and task on postural sway during quiet stance.

Gait & posture·2021
Same author

Factorial Structure of Trunk Motor Qualities and Their Association with Explosive Movement Performance in Young Footballers.

Sports (Basel, Switzerland)·2021

Related Experiment Video

Updated: Jun 25, 2026

"Avatar", a Modified Ex vivo Work Loop Experiments Using In vivo Strain and Activation
07:03

"Avatar", a Modified Ex vivo Work Loop Experiments Using In vivo Strain and Activation

Published on: August 18, 2023

Leg muscles design: the maximum dynamic output hypothesis.

Slobodan Jaric1, Goran Markovic

  • 1Department of Health, Nutrition, and Exercise Sciences, University of Delaware, Newark, DE 19716, USA. jaric@udel.edu

Medicine and Science in Sports and Exercise
|March 12, 2009
PubMed
Summary

Physically active individuals

Area of Science:

  • Biomechanics and Exercise Physiology
  • Human Movement Science

Background:

  • Muscles generate peak power at specific external loads.
  • Understanding optimal load for maximum dynamic output (MDO) is crucial for performance.
  • The role of body weight as an optimal load for lower-limb muscles is debated.

Purpose of the Study:

  • To propose and review evidence for the Maximum Dynamic Output (MDO) hypothesis.
  • To investigate if lower-limb muscles are optimized for movements against body weight.
  • To explore implications for assessing muscle function and adaptation.

Main Methods:

  • Review of existing literature, including evolutionary and anatomical considerations.
  • Analysis of experimental findings on power and momentum production during vertical jumping.

More Related Videos

Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
07:30

Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations

Published on: May 1, 2018

Construction of Constant-Load (Isotonic) and Constant-Velocity (Isokinetic) Torque-Velocity-Power Profiles In vivo for the Rat Plantar Flexors
07:44

Construction of Constant-Load (Isotonic) and Constant-Velocity (Isokinetic) Torque-Velocity-Power Profiles In vivo for the Rat Plantar Flexors

Published on: October 3, 2025

Related Experiment Videos

Last Updated: Jun 25, 2026

"Avatar", a Modified Ex vivo Work Loop Experiments Using In vivo Strain and Activation
07:03

"Avatar", a Modified Ex vivo Work Loop Experiments Using In vivo Strain and Activation

Published on: August 18, 2023

Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
07:30

Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations

Published on: May 1, 2018

Construction of Constant-Load (Isotonic) and Constant-Velocity (Isokinetic) Torque-Velocity-Power Profiles In vivo for the Rat Plantar Flexors
07:44

Construction of Constant-Load (Isotonic) and Constant-Velocity (Isokinetic) Torque-Velocity-Power Profiles In vivo for the Rat Plantar Flexors

Published on: October 3, 2025

  • Comparison of optimal loads for habitually active individuals versus strength-trained athletes.

    • Main Results:

    • Evidence suggests lower-limb muscles are designed for MDO against self-imposed loads (body weight and inertia).
    • Optimal load for vertical jumping power/momentum in active individuals may be their own body weight.
    • This implies body-size-independent MDO in rapid movements.

    Conclusions:

    • The MDO hypothesis offers a framework for understanding muscle structure-function relationships and adaptations.
    • Unloaded rapid movements (e.g., vertical jumps) could assess MDO in non-athletes.
    • This approach simplifies physical ability and neuromuscular function assessments.