Author(s): ISHIKAWA, M., NORO, H., HATA, K., YAMAZAKI, Y., LEE, R.Y., YANAGIYA, T., Institution: JUNTENDO UNIVERSITY, Country: JAPAN, Abstract-ID: 1458

INTRODUCTION:
The scoring in artistic gymnastics is based on the sum of the Difficulty Score (D-Score), reflecting the difficulty of the skills, and the Execution Score (E-Score), which evaluates the aesthetic quality of the performance. Traditional scoring relied on visual human judgment, leading to concerns about subjectivity and discrepancies in the location of judgment. Recently, AI scoring systems (Judging Support System, Fujitsu, Japan) have been used in international competitions for judging. An AI scoring system makes it possible to estimate 3D skeletal coordinates, without using reflective markers. Therefore, this system not only improves the accuracy of gymnastic motion evaluation but also provides insights into the technical corrections that can enhance athletic performance and reduce injury prevention. This study aimed to clarify the technical factors in the successful execution of “switch leap to ring position” using three-dimensional kinematic analysis with the AI scoring system.
METHODS:
Four female college gymnasts performed a total of 120 trials of “Switch to leap to ring position” leap on the balance beam over a 5-day practice period. The AI scoring system was used to identify successful and unsuccessful trials by tracking 18 body points to analyze the kinematic and kinetic of the movement. Specific criteria for success comprised three points: leg split over 180° in both forward and backward direction (Criteria 1), front foot positioned above the horizontal (Criteria 2), and back foot toe pointed above the head (Criteria 3).
RESULTS:
Of the 120 “Switch leap to ring position” trials, 82 were successful and 38 were unsuccessful. Out of 120 trials, 45 met Criteria 1 (leg split over 180°), 102 met Criteria 2 (front foot positioned above horizontal) and 68 met Criteria 3 (back foot toes pointed above toes). The 68 trials that cleared Criteria 3 were all successful performances. In contrast, only 41 attempts met all three requirements. Multiple regression analysis showed a significant correlation between Criteria 2 and 3 with skill certification. Successful trials had significantly greater splitting the leg angle in Criteria 1 and significantly higher back foot tiptop position in Criteria 2. Comparing the success and failure of the techniques, a significant difference in Criteria 1 and 3 was found. Successful trials showed a significantly higher average angular velocity (4.4rad/s) compared to unsuccessful trials.
CONCLUSION:
The most important factor to be recognized in the “Switch leap to ring position” on a balance beam about the toe of the back foot reaches above the top of the head (Criteria 3). Moreover, increasing the angular velocity of the swinging-up leg is more likely to be certified as a technique.