ABSTRACT


A comparative analysis on kinematic variables and muscle activity between Yeopchagi of two-feet stance posture and Yeopchagi movement of Hakdari seogi posture among the Taekwondo Poomsae


Kim, Se Won
Department sports medicine
Graduate School of Biomedical Science
Korea University
Supervised by prof. Kim, Chang Kook

The purposes of this research are to analyze image and muscle activity between Yeopchagi of two-feet stance posture and Yeopchagi movement of Hakdari seogi posture among the Taekwondo Poomsae, obtain kinematic and muscle activity data of two Yeopchagi, provide scientific basic data by finding movement organization factors, characteristics and similarities and differences of each seogi posture Yeopchagi, suggest effective direction of performance for guide''s correct guidance and Poomsae player''s Yeopchagi technological movement and contribute to the improvement of Poomsae player''s athletic performance. Research subjects were 6 male Poomsae players who were registered in Korea Taekwondo Association as Poomsae players with career of get a prize and the experiment was conducted by 6 cameras, wireless EMG and force platform. As a result, following conclusions could be obtained.

1. Kinematic variables

First, for the total time required, Yeopchagi of Hakdari seogi posture was more rapid than Yeopchagi of two-feet stance posture. In the time required by condition, Yeopchagi of Hakdari seogi posture showed both increase and decrease in performance time, but Yeopchagi of two-feet stance posture showed continuously decreased performance time by condition.

Second, in transfer of physical center, Yeopchagi of two-feet stance posture showed greater left/right movement and front/back movement than Yeopchagi and changing differences of up and down position were similar. In transfer speed of physical center, Yeopchagi of two-feet stance posture showed continuously increased speed of center from preparation posture to the final impact and Yeopchagi of Hakdari seogi posture showed differences of speed increase from the time when knee joint becomes minimum angle.

Third, in changes of hip joint angle, angular speed and each acceleration, there were significantly statistical differences for the right angel of hip joint in EVENT 1 and EVENT 2. And, angular speed [Right/E1,E2(ｐ＜.001)] and each acceleration didn''t show significantly statistical differences. Angular speed [E1~E4 (ｐ＞.05)], Each acceleration [E1~E4 (ｐ＞.05)]

Fourth, for changes of knee joint angle, angular speed and each acceleration, knee joint changes of Yeopchagi of two stance postures show same similarities in EVENT 3 and EVENT 4 without significantly statistical difference. Knee joint changes show significantly statistical differences in EVENT 1 and EVENT 2. For changes of knee joint angle [Right: E1,E2(ｐ＜.001)/Left: E1,E2(ｐ＜.001)] and each speed change of knee joint, angular speed of right knee joint showed significantly statistical differences in EVENT 2 [Right: E2(ｐ＜.05)]. And, in each acceleration, there was not significantly statistical difference in EVENT 1∼ EVENT 4. Each acceleration of knee joint [E1~E4 (ｐ＞.05)].

Fifth, for changes of ankle joint angle, angular speed and each acceleration, ankle joint of kicking foot didn''t show dorsiflexion at the time of impact striking the target during both Yeopchagi of two-feet stance posture and Yeopchagi of Hakdari seogi posture. And, there were significantly statistical differences in EVENT 1 and EVENT 2. Knee joint angle [Left: E1,E2(ｐ＜.001)], Angular speed of knee joint [Right: E2(ｐ＜.05)/Left: E2(ｐ＜.001)], Each acceleration of knee joint [E1~E4 (ｐ＞.05)].

2. Changes of muscle activity

First, on the first condition, straight muscle of thigh commonly showed the highest muscle activity in Yeopchagi of two-feet stance posture and Yeopchagi of Hakdari seogi posture and Yeopchagi of two stance postures was right straight muscle of thigh. The second highest muscle activity was straight muscle of thigh in Yepchagi of two-feet stance posture(L) and anterior tibial muscle in Yeopchagi of Hakdari seogi posture(L). And, if examining the characteristics of sequential muscle activity after the second muscle activity of Yeopchagi of two stand postures, Yeopchagi of two-feet stance posture showed the highest muscle activity in support foot and nextly, muscles of kicking feet showed muscle activity. Yeopchagi of Hakdari seogi posture showed the highest muscle activity in kicking foot and nextly, muscle activity was shown in muscles of support foot. Right gastrocnemius of Yeopchagi of two stance postures shows significantly statistical differences.
(Gastrocnemius/Rp＜.05)

Second, the muscle which showed the highest muscle activity in Yeopchagi of two-feet stance posture and Yeopchagi of Hakdari seogi posture on the second condition was same as the result of the first condition. The second highest muscle activity was shown in straight muscle of thigh and there were positional differences as Yeopchagi of two-feet stance posture was left straight muscle of thigh and Yeopchagi of Hakdari seogi posture was right one. So, there were significantly statistical differences in right bicephalus femoris(ｐ＜.05) and right gastrocnemius(ｐ＜.001).

Third, the muscle which showed the highest muscle activity in Yeopchagi of two-feet stance posture and Yeopchagi of Hakdari seogi posture on the third condition was support foot; left straight muscle of thigh in Yeopchagi of two-feet stance posture and right kicking foot in Yeopchagi of Hakdari seogi posture. During the Yeopchagi of Hakdari seogi posture, muscle activity of right straight muscle of thigh was higher than left straight muscle of thigh in the first condition ~ the third condition. During the Yeopchagi of two-feet stance posture, right straight muscle of thigh on the first condition and left straight muscle of thigh of the second condition and the third condition showed differences of muscle activity.

If synthesizing the results, kinematic differences and differences of muscle activity were shown in EVENT 1 because of the different positions between kicking foot and support foot as the characteristics of preparation posture in Yeopchagi of two-feet stance posture and Yeopchagi of Hakdari seogi posture. Kinematic differences and differences of muscle activity were shown in EVENT 1 and Yeopchagi of two-feet stance posture used external force on the ground in EVENT 2, but Yeopchagi of Hakdari seogi posture didn''t use external force on the ground. Therefore, there were kinematic differences and differences of muscle activity and there were common movement in EVENT3 and EVENT 4. However, there were differences of muscle activity according to the characteristics of posture and use of external force on the ground.