평행봉 Healy 버티기 동작의 3차원 운동학적 분석 = Three-dimensional Analysis of Healy Twist to Reward Swing in Support Motion on Parallel Bar

다국어 초록 (Multilingual Abstract)

The purpose of this study is to examine the kinematical mechanism on Healy rwist to reward swing in support motion, and to grope for the better swing technique on the parallel bar. The subjects were four national ranked gymnasts who participated in the 1996 olympic game and four collegiate gymnasts. 2 S-VHS vedio caneras were used for the three-dimentional cinemerographical analysis. Also a rectangular shape control point containing markers of known coordinates, which encompassed the space of movement, was constructed and filmed to permit caliblation of the movement, After the filming of the control point it was removed and the Healy twist to reward swing in support motion techniques of each subject were filmed. And for the synchronization of three cameras, it was used the moment of braking out the ballon as the syn-event. The Direct Linear Transformation(DLT) technique was employed to obtain 3-D position coordinates and a cubic spline function was used for smoothing and differentiation. And the selected kinematical variables were the leaning arms angles at release, the leaning arms gngles at regrasp, the shoulder and hip angle, the velocity change of the center of the mass and the horizontal and vertical displacement of the center of the mass, T-test was used to test for differences between the skilled and the less-skilled gymnasts in the selected kinematical variables using SPSS-PC statistical program. Based on the results of this study, the following conclusions are drawn; 1) Angle Variable There are statistically no significant difference between two group in the all of the angle variables such as leaning arm of at release & at regrasp, shoulder & hip angle of at regrasp. but The mean values between two group are all the difference. The skilled group all the larger angles than the less-skilled group. 2) Displacement Variable(center of mass) There are statistically no significant difference between two group in the all of the displacement variables at each phase, but the mean values between two group are all the difference. The skilled group showed the longer displacement than the less-skilled group in all the horizontal displacement at each phase and vertical displacement at regrasp, vertical position. The less-skilled group showed the longer vertical displacement than the skilled group at release and horizontal position. 3) Velocity Variable(center of mass) There are statistically no significant difference between two group in all of the velocity variables at all phase. but there are all the difference between the mean value of groups. The skilled group showed the higher resultant velocity at 1st and 2nd phase and the less-skilled group showed the higher resultant velocity at 3rd phase. The skilled group showed the higher horizontal velocity at 1st phase and the lower horizontal velocity at 2nd and 3rd phase than the less-skilled group. The skilled group showed the lower vertical velocity except 2nd phase than the less-skilled group. In summary, the skilled group performs the Healy twist to reward swing in support motion with the larger angle variables. This leads to increase the leaning arm angle and the height of regrasp position. The increased leaning arm, shoulder and hip angles lead to increase the velocity of the Healy motion. Therefore, the body position without crouch at all phase and the higher center of the mass at regrasp make easy to perform more than skills after the Healy swing motion.