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

Excitation-Contraction Coupling in Skeletal Muscles01:20

Excitation-Contraction Coupling in Skeletal Muscles

16.3K
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...
16.3K
Motor Unit Stimulation01:20

Motor Unit Stimulation

4.1K
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...
4.1K

You might also read

Related Articles

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

Sort by
Same author

Mechanobiological and neuromuscular responses to foot-position variations during front and back squat exercises.

Frontiers in physiology·2026
Same author

Perception of sexual harassment among female athletes participating in team sports in the Northern Cyprus.

Frontiers in psychology·2025
Same author

Relationship Between Anabolic-Androgenic Steroid Use, Aggression, and Narcissism in Male Bodybuilders.

Medicina (Kaunas, Lithuania)·2025
Same author

Kinematic and EMG activities during front and back squat variations in maximum loads.

Journal of sports sciences·2015

Related Experiment Video

Updated: Mar 1, 2026

Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise
09:21

Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise

Published on: August 25, 2022

3.9K

Kinematic and Electromyographic Activity Changes during Back Squat with Submaximal and Maximal Loading.

Hasan U Yavuz1,2, Deniz Erdag2

  • 1Department of Sports Medicine, Faculty of Medicine, Near East University, Nicosia, Northern Cyprus, Mersin 10, Turkey.

Applied Bionics and Biomechanics
|May 27, 2017
PubMed
Summary

Maximal loading in squats significantly increased muscle activity in the vastus medialis and gluteus maximus, but not other muscles. Increased forward lean during maximal loads may raise lumbar injury risk.

More Related Videos

Biomechanical Changes Related to Low Back Pain: An Innovative Tool for Movement Pattern Assessment and Treatment Evaluation in Rehabilitation
06:28

Biomechanical Changes Related to Low Back Pain: An Innovative Tool for Movement Pattern Assessment and Treatment Evaluation in Rehabilitation

Published on: December 13, 2024

1.5K
Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study
08:40

Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study

Published on: November 11, 2022

1.5K

Related Experiment Videos

Last Updated: Mar 1, 2026

Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise
09:21

Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise

Published on: August 25, 2022

3.9K
Biomechanical Changes Related to Low Back Pain: An Innovative Tool for Movement Pattern Assessment and Treatment Evaluation in Rehabilitation
06:28

Biomechanical Changes Related to Low Back Pain: An Innovative Tool for Movement Pattern Assessment and Treatment Evaluation in Rehabilitation

Published on: December 13, 2024

1.5K
Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study
08:40

Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study

Published on: November 11, 2022

1.5K

Area of Science:

  • Biomechanics
  • Exercise Physiology
  • Sports Science

Background:

  • The squat maneuver is a fundamental exercise for lower body strength.
  • Understanding the effects of maximal loading on muscle activity and kinematics is crucial for optimizing training and preventing injury.

Purpose of the Study:

  • To investigate kinematic and muscular activity changes during squat maneuvers with maximal loading.
  • To compare muscle activation and movement patterns at 80%, 90%, and 100% of one-repetition maximum (1RM).

Main Methods:

  • Fourteen experienced male individuals performed squats at 80%, 90%, and 100% of their 1RM.
  • Electromyographic (EMG) activity of key lower body and back muscles was recorded.
  • Kinematic data were analyzed using 2D analysis software.

Main Results:

  • Overall muscle activity increased with load, with significant increases in vastus medialis and gluteus maximus at 90% and 100% 1RM compared to 80%.
  • No significant differences in muscle activity were observed between 90% and 100% 1RM.
  • Maximal loading led to increased forward lean in the hip joint.

Conclusions:

  • Maximal loading in squats may not be essential for enhancing knee extensor strength.
  • Increased forward lean during maximal squats could elevate the risk of lumbar injury.