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Target kinematic effect in Kyokushin karate front kicks: an analysis of velocity, acceleration, and muscle activation patterns

2025; Volume: 13; Issue: 1 Linguagem: Inglês

10.16926/par.2025.13.14

2300-5076

Dariusz Mosler, Tomasz Góra, Jacek Kaczmarski, Monika Błaszczyszyn, Marcin Chociaj, Zbigniew Borysiuk,

Sports Performance and Training

Karate training involves extensive practice without physical targets. While target kinematic effect has been identified in taekwon-do, this phenomenon remains unexplored in Kyokushin karate. This study aimed to verify the extent of target kinematic effects in Kyokushin practitioners' front kicks through examination of acceleration, angular, and electromyographical data. Material and Methods: Nineteen male Kyokushin practitioners (mean age 27.05 years) participated. Movement data was collected using wireless sEMG system (3000 Hz) and MyoMotion inertial sensors IMU (ang. inertial measurement unit) (200 Hz). Participants performed front kicks under six conditions: before warm-up, after warm-up, and after shadow sparring, each with and without a target shield. Seven muscles were monitored via sEMG, while four inertial sensors tracked movement of the pelvis, thigh, shank, and foot. Results: Significant velocity differences emerged after shadow sparring (16.91 m/s target vs. 14.39 m/s non-target, p = 0.045). Foot segment acceleration nearly doubled with target presence (57.83 m/s² to 99.27 m/s²). Angular measurements showed consistent adaptations across body segments when striking the target. EMG analysis revealed limited differences, with only the rectus femoris showing significant changes in the initial phase. Conclusion: The study confirmed target kinematic effect in Kyokushin practitioners, manifesting through substantial changes in acceleration and joint angles, particularly in distal segments. Limited EMG differences suggest consistent muscle activation patterns despite technique modifications. These findings indicate air-striking practice may not fully replicate the biomechanical demands of striking physical targets.