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Updated: Jun 30, 2026
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In vivo Measurement of Knee Extensor Muscle Function in Mice
Published on: March 4, 2021
The effect of remote voluntary contractions on knee extensor torque
William P Ebben1, David H Leigh, Christopher F Geiser
1Program in Exercise Science, Department of Physical Therapy, Marquette University, Milwaukee, WI 53201, USA. webben70@hotmail.com
Medicine and Science in Sports and Exercise
|September 19, 2008
Summary
Remote voluntary contractions (RVC) significantly enhance isometric knee extensor torque, with a combination of jaw clenching, gripping, and the Valsalva maneuver yielding the greatest improvements. These findings support the concurrent activation potentiation (CAP) phenomenon.
Area of Science:
- Exercise Physiology
- Human Performance
- Neuromuscular Function
Background:
- Concurrent activation potentiation (CAP) is a phenomenon where contractions in muscles remote from the prime mover enhance force production.
- Remote voluntary contractions (RVC) are proposed to be the mechanism underlying CAP.
- Understanding RVC effects is crucial for optimizing strength and athletic performance.
Purpose of the Study:
- To investigate the impact of various RVC strategies on isometric knee extensor torque.
- To determine if RVC can augment maximal voluntary contractions (MVC).
- To provide empirical evidence for the existence of the CAP phenomenon.
Main Methods:
- Twelve resistance-trained males participated in the study.
- Subjects performed maximal voluntary isometric contractions (MVIC) of knee extensors under various RVC conditions and a no-RVC control.
- RVC conditions included jaw clenching, gripping, Valsalva maneuver, and combinations thereof.
Main Results:
- A significant main effect of RVC condition on knee extensor torque was observed (P = 0.001).
- Specific RVC combinations led to significant increases in torque compared to no RVC (P < 0.05).
- The combination of jaw clenching, bilateral gripping, and Valsalva maneuver increased average and peak torque by approximately 14.6% and 14.8%, respectively.
Conclusions:
- Remote voluntary contractions effectively augment isometric knee extensor torque.
- These findings support the existence and practical application of the concurrent activation potentiation (CAP) phenomenon.
- RVC strategies may be beneficial for enhancing strength during resistance training and athletic activities.
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