태권도 앞꼬아서기 옆차기의 운동역학적 분석

Abstract

Kinetic analysis of the Apkkoaseogi Yeopchagi in Taekwondo

Bo Seob Heo

Department of Physical Education The Graduate School Pukyong National University Directed by Professor Yong Jae Kim Ph.D.

Abstract

This paper is to establish the kinetic and kinematic factors of Apkkoaseogi(front cross stance) Yeopchagi(side kick) in Taekwondo through factors such as movement of the center of the whole body, the angle of the kicking foot, the supporting foot in the lower body, and the muscle activity and then describe the improvement in the skill for the Taekwondo Poomsae players. The study was performed targeting 6 awarded players who had the experience of winning at the national team competition and other nationwide competitions and 6 players who had no experiences at those competitions. After explaining to them the purpose and procedure of the test and getting the written consents from them, the test was conducted. For the test, 5 high speed digital cameras(Motion Master 100) and wireless EMG(QEMG-4, Lxtha Korea) were used to collect the data on 5 practices of Apkkoaseogi(front cross stance) Yeopchagi(side kick) in Taekwondo focusing on the movement of the center of the body, the angle of the hip joint, knee joint and the ankle joint, and the muscle activity of the femoral rectus muscle, biceps femoris, gastrocnemius muscle and tibialis anterior. Among them, 1 action which was judged to be the most perfect was chosen for analysis. By removing the first and last 2 seconds in the signal of surface electromyography test, the root mean square(RMS) and the % MVIC value were obtained for analysis. For the processing of the data, SPSS 21.0 software was used and the analyzed values were obtained including the average(M) and standard deviation(SD). For the identification of the difference between the awarded players and the non-awarded players, the independent sample t-test was conducted and the significant statistical level was set as(p< .05). The results were as follows. 1. Duration of Apkkoaseogi Yeopchagi in Taekwondo The duration of Apkkoaseogi Yeopchagi in Taekwondo at each phase showed a significant difference at the phase of P4(p< .05). 2. The Movement of the center of the body at Apkkoaseogi Yeopchagi in Taekwondo 1) As for the change in the movement of the center of the body of the longitudinal axis(Y axis), there were statistically significant differences in E1 Phase(p< .01), E2 Phase(p< .01), E3 Phase(p< .01), E4 Phase(p<. 01), E5 Phase(p< .05) and E6 Phase(p<. 05). 2) There were also statistically significant differences in the change in the movement of the center of the body of the vertical axis(Z axis) at the stages of E2 Phase(p< .05), E3 Phase(p< .05), and E4 Phase(p< .01). 3. Angle of lower body in the action of Apkkoaseogi Yeopchagi in Taekwondo 1) There were statistically significant differences in the right hip joint in E2 Phase(p< .01), E3 Phase(p< .01), and E6 Phase(p<. 01). There was a statistically significant difference in the left hip joint at the Phase E4(p< .01). 2) There was a statistically significant difference at the right knee joint in E6 Phase(p< .01) while there was a statistically significant difference(p< .05) at the left knee joint in Phases E2 and E6. 3) There was also a statistically significant difference at the right ankle joint in the phase E4(p< .05). 4. Muscle activity in the lower body at Apkkoaseogi Yeopchagi in Taekwondo 1) There were big muscle activities in the left and right side of the femoral rectus muscle and the statistically significant difference between them. 2) There were big muscle activities in the right side of the biceps femoris and the statistically significant difference. 3) There were big muscle activities in the right side of the gastrocnemius muscle and the statistically significant difference. In conclusion, the Apkkoaseogi(front cross stance) Yeopchagi(side kick) in Taekwondo needs a stable movement of the upper body and a stable posture of the kicking foot as well as the balance of the supporting foot. For a strong, fast Yeopchagi of 170°, there is a need for a strong power of repulsive power using the ground, the sequential use of the joints and the flexibility of the lower joints. For an effective Yeopchagi, the understanding and the repetitive training are required through a scientific approach and practices for strengthening the main muscle and the flexibility are required.