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Updated: Aug 6, 2025
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Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles
Published on: November 1, 2012
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Less fatiguability in eccentric than concentric repetitive maximal muscle contractions
Riku Yoshida1, Kazuki Kasahara1, Yuta Murakami1
1Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan.
European Journal of Applied Physiology
|March 19, 2023
Summary
Repetitive maximal concentric-only contractions caused greater torque loss than eccentric-only contractions, indicating higher muscle fatigue. However, maximal voluntary isometric contraction (MVC-ISO) did not reflect this difference in fatigue resistance.
Area of Science:
- Biomechanics and Exercise Physiology
- Muscle Physiology and Fatigue
Background:
- Understanding muscle fatigue profiles is crucial for optimizing training and rehabilitation protocols.
- Different contraction types (concentric, eccentric, and combined) elicit distinct physiological responses and fatigue patterns.
Purpose of the Study:
- To compare muscle fatigue profiles of elbow flexion using concentric-only, eccentric-only, and combined concentric-eccentric contractions.
- To analyze changes in torque and biceps brachii electromyogram (EMG) activity during repetitive maximal voluntary contractions.
Main Methods:
- Fifteen healthy young men performed 30 repetitive maximal voluntary contractions (concentric-only, eccentric-only, concentric-eccentric) on an isokinetic dynamometer.
- Torque and EMG data were recorded, along with maximal voluntary isometric contraction (MVC-ISO) before and after protocols.
- Statistical analysis involved two-way repeated measures ANOVA to compare changes among conditions.
Main Results:
- Torque significantly decreased across all conditions, with greater reductions in concentric-only and concentric phases of combined contractions compared to eccentric-only.
- Maximal voluntary isometric contraction (MVC-ISO) torque showed similar decreases after concentric-only and eccentric-only protocols, but a larger decrease after the combined protocol.
- Biceps brachii EMG activity decreased similarly across all conditions during contractions and in MVC-ISO tests.
Conclusions:
- Repetitive maximal eccentric contractions demonstrate greater fatigue resistance than concentric contractions.
- Maximal voluntary isometric contraction (MVC-ISO) may not fully capture the differential fatigue resistance observed between concentric and eccentric contractions.
- These findings have implications for designing exercise programs that target specific muscle fatigue characteristics.
Keywords:
Elbow flexorsElectromyogramLengthening muscle contractionMaximal voluntary isometric contractionMore Related Videos
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