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Induction and Assessment of Exertional Skeletal Muscle Damage in Humans
Published on: December 11, 2016
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Motor unit activity after eccentric exercise and muscle damage in humans.
Acta Physiologica (Oxford, England)
|April 25, 2014
Summary
Eccentric exercise causes muscle damage, altering nervous system muscle activation. Motor unit changes, like reduced conduction velocity, explain increased EMG and muscle fatigue for up to a week.
Area of Science:
- Exercise Physiology
- Neuroscience
- Muscle Biology
Background:
- Unaccustomed eccentric exercise induces muscle damage and soreness, impacting muscle function.
- The precise influence of this muscle damage on neural muscle activation remains unclear.
Purpose of the Study:
- To review the effects of eccentric exercise on nervous system muscle activation.
- To examine changes in motor unit activity using electromyography (EMG) and intramuscular recordings.
Main Methods:
- Analysis of surface electromyography (EMG) and intramuscular recordings.
- Review of existing research on motor unit activity post-eccentric exercise.
Main Results:
- Eccentric exercise alters the EMG-force relationship, affecting motor performance.
- Significant changes in motor unit recruitment thresholds, discharge rates, conduction velocities, and synchronization occur for up to a week.
- Increased submaximal EMG post-exercise is linked to decreased motor unit conduction velocity and antagonist coactivation.
Conclusions:
- Eccentric exercise profoundly impacts motor unit behavior and muscle activation.
- Further research is needed to confirm preferential damage to high-threshold motor units in humans.
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