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Relationship Between Intermuscular Synchronization of Upper Leg Muscles and Training Level in Karate Kumite
Velimir Jeknić1, Milivoj Dopsaj1, Nenad Koropanovski2
1Faculty of Sport and Physical Education, University of Belgrade, 11030 Belgrade, Serbia.
Journal of Functional Morphology and Kinesiology
|September 26, 2025
Summary
Karate training enhances neuromuscular adaptations, improving muscle synchronization. Elite karate practitioners show superior intermuscular synchronization, indicating optimized neural strategies for combat sports performance.
Area of Science:
- Sports Science
- Biomechanics
- Neuroscience
Background:
- Karate training may induce specific neuromuscular adaptations.
- Intermuscular synchronization in leg muscles is crucial for performance in sports like karate.
- The level of karate training might influence neuromuscular control and coordination.
Purpose of the Study:
- To compare neuromuscular response and intermuscular synchronization in thigh muscles across different karate experience levels and non-athletes.
- To investigate if karate training leads to neuromuscular adaptations.
- To determine if intermuscular synchronization is dependent on karate skill level.
Main Methods:
- Tensiomyography (TMG) was used to measure neuromuscular response in thigh muscles (rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinosus).
- Indexes of Intermuscular Synchronization (IIS) were calculated for contraction time (Tc), total contraction time (TcT), and rate of muscle tension development (RMTD).
- Participants included elite karate athletes (KE), sub-elite karate athletes (KSE), basic karate trainees (KB), and non-athletes (NA).
Main Results:
- Significant differences in intermuscular synchronization indexes were found between karate groups and non-athletes.
- Karate practitioners (KE, KSE, KB) showed shorter contraction time indexes in dominant knee extensors compared to non-athletes.
- Elite karate athletes (KE) demonstrated superior synchronization in non-dominant flexors compared to all other groups.
Conclusions:
- Muscle coordination patterns, assessed by TMG-based indexes, are sensitive to training level and laterality in karate practitioners.
- Elite athletes exhibit enhanced intermuscular synchronization, suggesting specific neuromuscular adaptations for high-level combat sports.
- Improved synchronization may reflect optimized neural strategies for stability, speed, and efficiency, valuable for performance diagnostics and training in combat sports.
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