| Summary: | 碩士 === 臺北市立體育學院 === 運動技術研究所 === 99 === Purpose: This study aimed to analyze the biomechanical characteristics of side snap kick movements in elite karate athletes. Method: Five elite karate athletes who are national team members and holders of international titles were analyzed by the Hawkeye digital video recorder system and the AMTI force platform record system. The data was analyzed statistically in order to understand the technical characteristics of the karate side snap kick. Results:1. Leg Lifting Phase: In order to increase the speed at which the knee is raised, the angles of both joints in the lower limb are reduced because of the generation of secondary vertical counterforce when the ball of the foot leaves the ground. 2. Leg Snapping Out Phase: The angle of each joint is extended and enlarged to generate maximum attack speed; creating a state where body weight is transferred, causing minimum vertical counterforce and facilitating the generation of maximum attack force. 3. Leg Snapping Back Phase: Each joint of the lower limb is contracted in order to rapidly increase the speed at which the leg snaps back and to generate secondary angular velocity and angular acceleration. 4. Landing Phase: The angles of hip and knee joints are increased as the movement is finished and landed, and the angle of the ankle joint is decreased as the ball of the foot touches the ground. Body weight is transferred once again when the kick moves back from the Leg Snapping Back Phase to the Landing Phase. Conclusion: 1. In the Leg Snapping Out Phase and the Leg Snapping Back Phase of karate side snap kick movements, the hip, knee and ankle joints all extend out and snap back rapidly, causing the displacement of each angle and generating peak levels of angular velocity and angular acceleration. 2. The biggest change of vertical counterforce is crucial in the Leg Snapping Back Phase and during knee lifting. Hence, kicking movements in karate are not only about attack strength, but also the supporting power and the steadiness of motion in the lower limbs. The average peak value is 16.038±1.104g. The manner of karate snap side kicks is in accordance with the kinematic chain and the kinetic chain principle in each joint of the lower limbs.
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