Motoshima Y., Maeda A. KASAMATSU VERSUS TSUKAHARA VAULT Vol. 7 Issue 2: 15 - 24 KASAMATSU VERSUS TSUKAHARA VAULT Yoshie Motoshima1, Akira Maeda2 1 Graduate School of Physical Education, National Institute of Fitness and Sports in Kanoya, Japan 2 National Institute of Fitness and Sports in Kanoya, Japan _Original article Abstract In the gymnastics vault, many male gymnasts presently perform vaulting of the Kasamatsu type in competitions. The purpose of this study was to clarify the characteristics of the vaulting motion of the Kasamatsu vault in comparison with the Tsukahara vault. Six male college gymnasts performed the Kasamatsu and Tsukahara vaults. Their vaulting motion was captured by the 3-dimensional optical motion capture system MAC3D. For both the Kasamatsu and Tsukahara vaults, horizontal velocity of the center of mass decreased, vertical velocity increased, and angular momentum was produced in the board contact phase. In addition, horizontal and vertical velocity decreased in the vault contact phase. However, no significant difference was observed between both vaults. The contribution of the upper limbs to angular momentum about the center of mass was significantly higher for the Kasamatsu vault than that for the Tsukahara vault at vault takeoff. These results suggest that the turn during the Kasamatsu vault was performed with rotation of the lower limbs being suppressed and angular momentum being maintained using the upper limbs. Keywords: biomechanics, gymnastics, kinamtics, upper limbs, lower limbs. INTRODUCTION The vaulting motion is composed of the run-up, board contact, pre-flight, vault contact, post-flight, and landing phases. Among them, it is possible to alter the mechanical parameters in the board and vault contact phases, but the force that can be adjusted in the vault contact phase is slight, and it is difficult to make up for an error by the vault contact phase if it occurs during the board takeoff motion (Prassas, 1999). The force in the board contact phase is important to the success of vaulting performance (Takei, Dunn, & Blucker, 2003). There are 3 types of vaults: front handspring, sideways handspring, and Yurchenko. With respect to the front handspring type, it has been reported that there is a positive correlation between distance of the post-flight phase and horizontal velocity of the center of mass at board takeoff (Cheetham, 1983), velocity and angular velocity in the pre-flight and vault contact phases are important determinants for the success of the 'handspring and somersault forward tucked' (King, Yeadon, & Kerwin, 1999; Takei, 1988), the force in the vault contact phase affects the height of the center of mass and the number of rotations of the somersault (Takei, 1991a, 1991b), and the force in the board contact phase is an important factor Science of Gymnastics Journal 15 Science of Gymnastics Journal Motoshima Y., Maeda A. KASAMATSU VERSUS TSUKAHARA VAULT Vol. 7 Issue 2: 15 - 24 (Takei, Dunn, & Blucker, 2003). With respect to the Yurchenko type, it has been reported that touching down on the springboard by raising the upper body and increasing the vertical velocity of the center of mass by block motion in the vault contact phase affect the height and distance of the post-flight phase (Uzunov, 2010). As noted, there have been many studies showing the importance of the board contact and vault contact phases in vaults of the front handspring and Yurchenko types. However, with respect to the Kasamatsu type, which is a sideways handspring type of vault that many male gymnasts have been performing in competitions in recent years, although it has been reported for hand placement (Kerwin et al., 1993) and kinematic parameters of Kasamatsu vault with 1 turn (Akopian) (Farana, Uchytil, Jandacka, Zahradnik, & Vaverka, 2014), biomechanical study of vault of the Kasamatsu type is less than the front handspring type. The Kasamatsu vault was first pioneered by Shigeru Kasamatsu at the 1974 World Cup. This vault is performed by a handspring with 1/4 turn in pre-flight and a backward somersault with 3/4 turn in post-flight. In the vaults of the Kasamatsu type, the D-score is incremented by 0.4 for each additional 1/2 turn in the post-flight phase. Kasamatsu vault with 2 turns (Lopez, D-score 6.0) is described in the code of points of men's artistic gymnastics as the vault of the highest difficulty among the Kasamatsu-type vaults (FIG, 2013). The motions of board contact and vault contact are also important factors for the success of Kasamatsu-type vaults, and it is important to clearly teach the motions and techniques in order to effectively improve performance. Therefore, the present study aimed to clarify the characteristics of the vaulting motion of the Kasamatsu vault by comparison with the Tsukahara vault, which is a sideways type that does not have a turn in the post-flight phase. METHODS Subjects Six male college gymnasts (age: 20.0±1.5 years, height: 1.64±0.04 m, body mass: 59.6±3.7 kg, competition history: 11.5±2.3 years) volunteered to participate in this study. After explaining the purpose, measurement content, risks, and data management of the study, informed consent was obtained from each subject. This study was conducted in accordance with the Declaration of Helsinki and approved by the ethics committee of the National Institute of Fitness and Sports in Kanoya. Measurement methods and data processing After sufficient warm-up, subjects performed the Kasamatsu vault (D-score 4.4, Figure 1) and Tsukahara vault (D-score 3.6, Figure 2) each twice randomly. All trials were recorded using the 3-dimensional optical motion capture system MAC3D (Motion Analysis Corp., USA, 400Hz), and the performance was scored by a certified judge of the Japan Gymnastics Association. A higher trial of E-score, indicating the quality of the performance, was selected for analysis for each vault. A reflective marker with a diameter of 18mm, which was attached to the body portion of the subject, was captured by synchronized Raptor 12 cameras, and 3-dimensional coordinates were recorded by Cortex 3.1.1 (Motion Analysis Corp., USA) key software. The reflective makers were attached to the parietal, front head, rear head, acromion (left and right), lateral epicondyle of the humerus (left and right), ulnar styloid process (left and right), third metacarpal bone (left and right), lower end of the scapula (right), sacrum, lower rib (left and right), anterior superior iliac spine (left and right), greater trochanter (left and right), lateral epicondyle of the femur (left and right), heel bone (left and right), external condyle fibula (left and right), and third metatarsal bone (left and right). The coordinate system was set to a static coordinate system consisting of X-axis Science of Gymnastics Journal 16 Science of Gymnastics Journal Motoshima Y., Maeda A. KASAMATSU VERSUS TSUKAHARA VAULT Vol. 7 Issue 2: 15 - 24 vector in the horizontal direction with respect to the advancing direction, Y-axis vector in the advancing direction, and Z-axis vector in the vertical direction. The plus X-axis represented the direction in which each subject turned. The 3-dimensional coordinate values obtained by MAC3D were smoothed using a fourth-order lowpass Butterworth filter with 10.3-19.5Hz cut-off frequency calculated by residual analysis (Winter, 2009) . Evaluation items Based on the smoothed 3-dimensional coordinates, the body was regarded as a rigid body composed of 15 segments, and velocity of the center of mass, angular velocity of trunk and lower limbs, and angular momentum about the center of mass (Hay et al., 1977) were calculated using the inertia coefficient of the body segments in Japanese athletes (Ae et al., 1992). In addition, angular momentums of the head, trunk, right upper limbs, left upper limbs, right lower limbs, and left lower limbs were calculated, and their contribution was calculated by dividing by the angular momentum of the whole body. The performance of the vault was divided into four phases: board contact phase (to board takeoff from board touchdown), pre-flight phase (to vault touchdown from board takeoff), vault contact phase (to vault takeoff from vault touchdown), and post-flight phase (to landing from vault takeoff). The time of each phase was calculated. Statistical analysis Descriptive data are presented as mean and standard deviation. After the tests of normality and equal variance, two-way ANOVA with repeated measures (vaults vs. phases) was used to test changes in the velocity and angular momentum of the two vaults. If significant main effects were found, Bonferroni post-hoc test was used to identify the differences. The paired t-test was used to compare the two vaults. This statistical analysis was performed using the IBM SPSS Statistics 22 (IBM Corp., USA) and the significance level was set at p<0.05. RESULTS Motion time of each phase Table 1 shows the results of the time of each phase. There was no significant difference in the times of board support, pre-flight, vault support, and post-flight phases between the two vaults. Velocity of the center of mass Horizontal velocity of the center of mass was not an observed interaction between vaults and phases. A main effect was not observed for the vaults, but was observed for phases (F=268.846, p<0.001). The post-hoc tests showed horizontal velocity of the center of mass significantly decreased in board takeoff from board touchdown (p<0.001) and in vault takeoff from vault touchdown (p<0.01, Table 2). Vertical velocity of the center of mass was not an observed interaction between vaults and phases. A main effect was not observed for the vaults, but was observed for phases (F=1798.924, p<0.001). The post-hoc tests showed vertical velocity of the center of mass significantly increased in board takeoff from board touchdown (p<0.001) and decreased in vault touchdown from board takeoff, vault takeoff from vault touchdown, and landing from vault takeoff (p<0.001, Table 2). Angular momentum about the center of mass Angular momentum about the center of mass was not an observed interaction between vaults and phases. A main effect was not observed for the vaults, but was observed for phases (F=452.77, p<0.001). The post-hoc tests showed the absolute value of angular momentum significantly increased in board takeoff from board touchdown and decreased in vault takeoff from landing (p<0.001, Table 2). Regarding the contribution of each body segment in angular momentum, there was no significant difference between the vaults at board touchdown, board takeoff, or vault touchdown (Table 3). On the other Science of Gymnastics Journal 17 Science of Gymnastics Journal Motoshima Y., Maeda A. KASAMATSU VERSUS TSUKAHARA VAULT Vol. 7 Issue 2: 15 - 24 hand, the contribution of the upper limbs in the Kasamatsu vault was significantly higher than that in the Tsukahara vault (p<0.05), and the contribution of the right lower limbs in the Kasamatsu vault was significantly lower than that in the Tsukahara vault at vault takeoff (p<0.05, Table3). The contribution of the left upper limbs in the Kasamatsu vault was significantly lower than that in the Tsukahara vault (p<0.05, Table 3). Angular velocity of trunk and lower limbs Angular velocity of the trunk was not an observed interaction between vaults and phases. A main effect was not observed for the vaults, but was observed for phases (F=66.865, p<0.001). The post-hoc tests showed the absolute value of angular velocity of the trunk significantly increased in board takeoff from board touchdown (p<0.01, Table 4). On the other hand, angular velocity of the lower limbs was an observed interaction between vaults and phases (F=8.133, p<0.001). A simple main effect was observed for the vaults at vault takeoff (F=16.635, p<0.01). In addition, a simple main effect was observed for phases (F=876.824, p<0.05), changing significantly in board takeoff from board touchdown (p<0.05), vault touchdown from board takeoff (p<0.05), and landing from vault takeoff (p<0.001, Table 4). Table 1 Motion time of each phase Kasamatsu vault Tsukahara vault t-test Board contact phase (s) 0.124 = O.OOS 0.128 = 0.007 n.s. Pre-flight phase (5) 0.067 = 0.023 0.069 = 0.022 n.s. Vault contact phase (s) 0.2 S 3 = 0.036 0.296 = 0.029 n.s. Post-flight phase (s) 0.865 = 0.026 0.842 = 0.030 n.s. Table 2 Velocity of the center of mass and angular momentum about the center of mass. Science of Gymnastics Journal 18 Science of Gymnastics Journal Motoshima Y., Maeda A. KASAMATSU VERSUS TSUKAHARA VAULT Vol. 7 Issue 2: 15 - 24 Variables Kasamatsu vauh Tsukahara vauh Vaults vs. Phases Vaults Phases Horizonta] velocity (m/s) F=26S.S46 Beard touchdown Board takeoff Vauh touchdown Vault takeoff Landing 7.24 4.89 4.68 3.10 3.01 = 0.23 0.23 0.31 0.24 0.47 7.21 4.91 4.77 3.00 2.96 = 0.17 0.21 0.31 0.40 0.41 F=0.993 n.s. F=0.585 n.s. j *** ]n.s. j ** Vertical velocity {ni's} F=1798.924 Board touchdown Board takeoff Vault touchdown Vault takeoff Landing -1.46 4.23 3.43 2.47 -3.75 0.14 0.1S 0.18 0.09 0.56 -1.51 4.17 3.28 2.14 -3.63 - 0.15 0.14 0.17 0.27 0.71 F=0.884 n.s. F=5.043 n.s. ] ##* j *** j *** j *** Angular momentum (kgm /s) F=452.779 ### Board touchdown Board takeoff Vauh touchdown Vaüh takeoff Landing -5.9 -79.6 -79.0 -82.7 -44.0 - 1.5 4.1 5.1 8.1 6.6 -5.3 -78.3 -7S.0 -81.6 -18.S - 2.3 6.2 6.5 6.0 L0.3 F=0.643 n.s. F=0.002 n.s. j *** ]tl.S. ]n.s. j *** ** :p<0.01: ***: p<0.001 Table 3 Contribution of each body segment to angular momentum. Science of Gymnastics Journal 19 Science of Gymnastics Journal Motoshima Y., Maeda A. KASAMATSU VERSUS TSUKAHARA VAULT Vol. 7 Issue 2: 15 - 24 Variables Kasamatsu vauh Tsukahara vauh t-test 3oard touchdown (%) Head -16.4 = 13.5 -22.9 = 20.8 n.s. Trank: -3.3 - 4.3 -9.4 - 14.3 n.s. Upper limbs (Right) -15.5 = 32.7 -13.2 = 44.5 n_s. Upper limbs (Left) -35.6 = 31.3 -36.S = 49.9 n.s. Lower limbs (Right) 75.3 = 31.7 95A ± 46.9 n.s. Lower limbs (Left) 95.5 = 41.4 S7.1 = 69.1 n.s. 3oard takeoff (To) Head 12.7 =0.8 12.6 = 0.7 n.s. Trunk 11.2 = 0.8 11.5 = 0.8 n.s. Upper limbs (Right) 9.3 = 1.6 9.3 = 1..7 n.s. Upper limbs (Left) 8.9 = 1.5 8.2 = 2.3 n.s. Lower limbs (Right) 25.2 = S.9 23.7 = 7.1 n.s. Lower limbs (Left) 32.7 = 9.8 34.7 = 8.5 n.s. Vauh touchdown (%) Head 11.4 = 1.4 11.8 = 1.3 n.s. Trunk 10.4 = 1.2 10.5 = 0.6 n.s. Upper limbs (Right) 8.2 = 0.8 8.2 = 1.3 n.s. Upper limbs (Left) 7.2 = 1.5 7.0 = 1.6 n.s. Lower limbs (Right) 26.3 = 12.9 254 = 9.6 n.s. Lower limbs (Left) 36.6 = 14.0 37.1 = 1.0.8 n.s. Vauh takeoff (%) Head 13.3 = 1.5 11.8 = 2.1 n.s. Trunk 10.7 - 1.4 11..5 - 0.5 n.&. Upper limbs (Right) 7.1 = 3.2 3.6 = 1.8 * Upper limbs (Left) 7.8 = 1.3 5.8 = 1.5 ** LottVct limbs (Right) 30.8 _ 2.4 349 _ 2.5 * Lower limbs (Left) 30.4 = 3.7 32.3 = 3.1 n.s. landing (%) Head 25.5 = 5.4 24.5 = 6.3 n.s. Trunk 20.7 = 3.3 19.1 = 4.7 n.s. Upper limbs (Right) 5.9 = 3.2 6.5 = 3.0 n.s. Upper limbs (Left) 2.9 = 2.9 6.7 = 3.3 1(1 Lower limbs (Right) 21.0 = 3.6 20.3 = 1..6 n.s. Lower limbs (Left) 24.0 = 3.7 22.9 = 2.9 n.s. * :jk0.05: * *: p<0_01 Table 4 Angular velocity of trunk and lower limbs. Science of Gymnastics Journal 20 Science of Gymnastics Journal Motoshima Y., Maeda A. KASAMATSU VERSUS TSUKAHARA VAULT Vol. 7 Issue 2: 15 - 24 Variables Tsukahara vault Kasamatsu vault Vaults vs. Phases Vaults Phases Trunk angular velocity (deg/s) Board touchdown Beard takeoff Vault touchdown Vault takeoff Landing 193.S ± Î0.2 -397.7 = 42.5 -352.8 = +9.8 -471.0 = 35.5 -443.Î = lfil.fi lSj.O ± 26.4 -403.6 = 40.7 -365.8 = 39.6 -302.4 = 55.8 -458.3 = 235.3 F=1451 F=1.212 F=56.865 *** ]n.s. ]n.s. 1 il.5. Lower limb angular velocity (deg/s l Board touchdown -365.0 = 40.0 -334.1 = 70.9 Board takeoff -534.0 = 29.4 -532.6 = 66.7 Vault touchdown -605.3 = 101.7 -578.3 = 66.9 Vault takeoff -500.: = 65.7 -722.S = 54.9 Landing -78 2 = 117.6 -83.7 = 83.5 F=S 133 F=1.757= n.s. F=0.002, n.s. F=1.387, n.s. F= 16.63 5. *" F=0.035, n.s. Kasamitsu Tïjkalma F=7ft.Sit in j ]n.5. j ** F=L