Korean Journal of Sport Biomechanics 2016; 26(1): 71-82 KJSB http://dx.doi.org/10.5103/KJSB.2016.26.1.71 ORIGINAL http://e-kjsb.org eISSN 2093-9752 Kinematic Comparisons of the Tsukahara Vault between a Top-level Athlete and Sublevel Collegiate Athletes Cheol-Hee Park1, Young-Kwan Kim2, Chang-Yei Back1 1Department of Physical Education, Graduate School, Chonnam National University, Gwangju, Korea 2Department of Physical Education, College of Education, Chonnam National University, Gwangju, Korea Received : 31 January 2016 Objective: The purpose of this study was to investigate kinematic comparisons of Revised : 22 February 2016 Tsukahara vault in gymnastics between a top-level athlete and sublevel collegiate athletes in order to obtain information on key biomechanical points for successful Tsukahara Accepted : 18 March 2016 vaults. Methods: An Olympic gold medalist (height, 160 cm; weight, 52 kg; age, 25 years) and five sublevel collegiate gymnasts (height, 168.2 ± 3.4 cm; weight, 59.6 ± 3.1 kg; age, 23.2 ± 1.6 years) participated in this study. They repeatedly performed Tsukahara vaults including one somersault. Fourteen motion-capturing cameras were used to collect the trajectories of 26 body markers during Tsukahara vaults. Event time, displacement and velocity of the center of mass, joint angles, the distance between the two hands on the horse, and averaged horizontal and vertical impact forces were calculated and compared. Results: The top-level athlete showed a larger range of motion (ROM) of the hip and knee joints compared to sublevel collegiate athletes during board contact. During horse Corresponding Author contact, the top-level athlete had a narrow distance between the two hands with extended Young-Kwan Kim elbows and shoulders in order to produce a strong blocking force from the horse with a Department of Physical shorter contact time. At the moment of horse take-off, reactive hip extension of the top-level Education, Chonnam National athlete enhanced propulsive take-off velocity and hip posture during post-flight phase. University, 77 Yongbong-ro, Conclusion: Even though a high velocity of the center of mass is important, the posture Buk-gu, Gwangiu, 61186, Korea and interactive action during horse contact is crucial to post-flight performance and the Tel : +82-62-530-2553 advanced performance of Tsukahara vaults. Fax : +82-62-530-2563 Email : [email protected] Keywords: Tsukahara vault, Gymnastics, Kinematics I. INTRODUCTION rently 6.4]) and successfully performed it in the London Olympic Games in 2012, resulting in a gold medal. This The vault, an artistic gymnastics skill, is one of the major has improved South Korea's international standing in vault medal events in the Olympic Games for South Korea. events. Continuous efforts have been made by athletes, Jong Hoon Park won the first bronze medal in the Seoul coaching staff, and sports scientists to enhance perform- Olympic Games in 1988, and Ok Ryul Yoo and Hong Chul ance, enabling the new technique to be developed and Yeo won a bronze medal in the Barcelona Olympic Games improved, which has resulted in top-level achievements. in 1992 and a silver medal in the Atlanta Olympic Games According to recent changes in the gymnastics rules, in 1996, respectively. In addition, Hak Seon Yang developed all athletes must demonstrate 2 different techniques in a new technique (YANG Hak Seon, difficulty score 7.4 [cur- competition. The International Federation of Gymnastics Copyright ○C 2016 Korean Journal of Sport Biomechanics This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by- nc/3.0/) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 72 Cheol-Hee Park, et al. KJSB (Federation Internationale de Gymnastique, 2013) has de- new type of vaulting table is used. Previous papers found cided that athletes must perform 2 different kinds of vault that it was difficult to increase take-off momentum be- motions from different groups (EG-I to EG-V) in prelim- cause of the sideways approaching to the horse in the inary rounds and final rounds, respectively. Among the Tsukahara technique, resulting in a longer horse contact different technique groups, the favorite one for Korean time and the majority of the weight being supported by men is the Tsukahara type (Group IV) (Yeo, 2003). Recently, one arm (Dilman, Cheetham, & Smith, 1985; Park, Youn, in order to enhance their chances of winning medals, they Back, Kim, & Chung, 2003). However, the new vaulting have also often used the handspring type (Group III) pre- table with a rounded front and wide top area for a stable ferred by western athletes. The Tsukahara vault is com- touch introduced in 2001 is more beneficial for the twist posed of board take-off, sideways hands touch down on of the Tsukahara type compared to other techniques (Park the horse, and stretched take-off with a backward salto, & Kim, 2014). In addition, it has been reported that the during which a technical difficulty score depends on the new type of vaulting table enables an increased take-off number of twist rotations in the air (Lee, Back, Kim, & force from horse blocking, and the development of various Kong, 2005). In contrast, the handspring technique is com- post-flight techniques (Back et al., 2005). posed of motions with a forward approach and both hands From the perspective of the training field, it is necessary touch-down on the horse simultaneously, which is bene- to completely master the basic Tsukahara technique in ficial in obtaining greater heights and also in generating order to perform advanced Tsukahara techniques. A number sagittal rotation, enabling various techniques to be applied. of studies have shown that it is only possible to perform The Tsukahara technique induces reverse torque in the advanced techniques successfully when basic techniques horse contact phase, so it is advantageous for producing are perfectly mastered (Lee et al., 2006). Hence, it is neces- twist moment of the body (Park & Kim, 2014). sary to objectively evaluate the basic techniques of athletes To date, research on gymnastic vaulting has revealed and give correct feedback of kinematic measurements while strategic factors that enhance the post-flight time and athletes learns basic techniques. facilitate advanced techniques. It has already been re- Therefore, the present study captured basic Tsukahara ported that a fast horizontal velocity in the approach run techniques from athletes at different levels using the new to the horse is essential for reaching a high vertical velocity vaulting table and conducted kinematic analyses. Through in post-flight (Park & Song, 2012; Lim, 2004; Takei, 1988, comparative analysis of kinematic factors, this study aimed 1989, 1996, 1998, 2007; Yeadon, King, & Springings, 1998), to find out the strengths and weaknesses of a top-level and it was also revealed that it is critical to generate a athlete and sublevel athletes, and to identify key points vertical component of propulsion for successful perform- of the Tsukahara vault required for performing advanced ance through a strong blocking at horse contact in order techniques. In addition, the secondary aims were to pro- to obtain vertical velocity effectively (Lee, Park, & Lee, vide coaches and young athletes intending to learn the 2006; Lee, Song, & Park, 2012). At the moment of horse Tsukahara technique for the first time with basic data to contact, elbow and shoulder joints should not be flexed, perform evidence-based training. In addition, this study and the center of mass should not be displaced forward specifically describes the postures of both hands at the in the direction of movement (Yeo, 2006). moment of horse touch-down, which were overlooked in Among studies on the vault, however, only a few studies previous studies. have focused on basic motions using the new type of vaulting table. Early studies on basic motions were con- II. METHODS ducted with the old type of vaulting table, and recent studies using the new type of vaulting table have only 1. Study subjects dealt with the application of highly advanced motion analysis. Thus, the results of early studies on basic motions The top-level athlete (A) was YHS, a gold medalist of are inappropriate to current training situations where the the vault in the 2012 London Olympic Games, who was Korean Journal of Sport Biomechanics KJSB Kinematic Comparisons of the Tsukahara Vault between a Top-level Athlete and Sublevel Collegiate Athletes 73 able to perform the Tsukahara 1260°. Sublevel athletes (B) 2. Study equipment were 5 collegiate athletes who could perform a 360° twist motion in the Tsukahara. The average difficulty score (D- For motion measurements, 8 indoor infrared cameras score) of the sublevel athletes was 4.4 points, which was (Osprey®, Motion Analysis, USA) and 6 outdoor infrared lower than that of normal collegiate athletes (5.2 points). high-speed cameras (Raptor-E®, Motion Analysis, USA) were Anthropometric data and D-scores of the subjects are used together. Cameras were operated using manufacturer- presented in Table 1. According to the code of research provided software (Cortex 4.0®, Motion Analysis, USA), in ethics, written informed consent forms were received from which the sampling rate was set to 200 Hz. To acquire the participants prior to the experiment. and analyze the desired motion data, 26 19-mm reflective markers were attached to major anatomical points, in which a 15-segment body model was used (Figure 1, Table 2). A Table 1. Anthropometric data of subjects and their D-score global coordinate system was set up with the forward in performance movement direction as the X axis, the Y axis on the per- Height Weight Career Age Score pendicular line in the horizontal plane, and the vertical (cm) (kg) (yr) (yr) (D-score) direction as Z axis.