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Does eccentric-exercise-induced jaw muscle soreness influence brainstem reflexes?
Tetsurou Torisu1, Kelun Wang, Peter Svensson
1Center for Sensory-Motor Interaction (SMI), Laboratory for Human Experimental Pain Research, Aalborg University, Fredrik Bajers Vej 7 D-3, DK-9220 Aalborg, Denmark.
Summary
Eccentric jaw exercises induced muscle soreness, which increased exteroceptive suppression (ES) brainstem reflexes but did not significantly alter the jaw-stretch reflex in healthy men.
Area of Science:
- Neuroscience
- Physiology
- Pain Research
Background:
- Muscle pain can influence neural reflexes.
- Eccentric exercises are known to induce muscle soreness.
- Brainstem reflexes play a role in motor control and sensory processing.
Purpose of the Study:
- To examine how eccentric jaw exercise-induced soreness affects brainstem reflexes.
- To investigate the impact on the short-latency jaw-stretch reflex and long-latency exteroceptive suppression (ES).
- To determine if soreness magnitude correlates with reflex changes.
Main Methods:
- Fifteen healthy men underwent eccentric jaw exercises for 30 minutes.
- Jaw-closing muscle reflexes were recorded before, immediately after, and one day after exercise.
- A control session without exercise was included for comparison.
Main Results:
- Muscle soreness was significantly elevated until one day after exercise.
- Exteroceptive suppression (ES) responses showed a trend towards increased inhibition post-exercise.
- A significant correlation was found between ES response and maximum biting soreness.
Conclusions:
- Muscle soreness from eccentric jaw exercises differentially affects brainstem reflexes.
- The jaw-stretch reflex remained unchanged, while ES responses were modulated.
- These findings suggest varying effects of muscle pain types on brainstem reflexes.
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