Biomechanical Analysis of SPIN KICKS for Establishing the Technical Difficulty of Free style Poomsae in Taekwondo

Purpose: Quantitative grounds for the difficulty distinction and clear evaluation criteria of Taekwondo free style Poomsae spin kick are required. The purpose of this research is to conduct a kinematic analysis of 540°Dwihuryochagi(540D), 720°Dollyochagi(720D) and 900°Dwihuryochagi(900D) and provide a quantitative basis for spin kick difficulty classification. Method: 13 athletes(age: 20.6±0.7 years, height: 171.3±4.2 cm, weight: 65.4±6.2 kg, experience: 8.3±4.5 years) were selected for this study. The analysis variables were the interval-specific time required for the spin kick, the displacement and velocity of the center of mass(COM), and the rotation angle and rotation angular velocity of the trunk. Results: First, as the rotation angle increased, the time to kick(E2-E4) increased and the height of kick-off(E4) COM decreased(p<.05). Second, it has been shown that the time to land(E4-E5) is shortened(p<.05). The 900D was followed by kick after the landing was completed. Third, for the rotational angular velocity of the torso, rapid angular velocity was shown in the order of 900D > 720D > 540D in the air rotation interval(Phase 2-5). Conclusion: Based on the results of this study, the difficulty of 900D should be allocated higher than that of 540D and 720D. In addition, Video Assistant Referee(VAR) techniques need to be applied to evaluate the suc-cess of 900D.