A Biomechanical Analysis Of The Compulsory HECHT Vault

Abstract

In this study, junior and 4 senior elite gymnasts competing in the 1993 Men's Winter National Competition werc videotaped performing the compulsory hecht vault for the first time in national competition. This vault, which will be performed at the 1996 Olympic Game, differs from other vaults being done today because it requires the gymnast to change his direction on of rotation between the preflight and postflight phases of the vault. Since gymnasts have not yet mastered this skill, a 2D kinematic analysis was done to compare characteristics of high and low scoring vaults in attempt to provide coaches with some information regarding those characteristics critical to success. The 14 highest scoring vaults, the 14 lowest scoring vaults, and an additional 10 vaults performed by national team members were digitized at 100 Hz and analyzed using the PEAK Performance, Inc. system for motion analysis. Kinematic variables of interest, such as the angle and angular velocity of the segment relative to horizontal and the angles of the shoulder and the hip joints, were computed for the preflight, repulsion, and postflight phases of the vault. These parameters were compared with gymnasts' scores and maximum height attained during postlight. Results of the study indicate that U.s. gymnasts are using three . different techmques to perform this vault, characterized by the degree of hip flexion exhibited in the repulsion and postflight phases of the vault. No significant differences in score distribution were observed between groups of gymnasts using the different techniques. Within each group, however, the highest scores were awarded to gymnasts whoso trunk angle at contact relative to horizontal was greater tban 10 degrees. These gymnasts had greater shoulder angles at contact and achieved a greater angular velocity of the trunk relative to horizontal during postflight than the lower scoring gymnasts. Future studies must be done to determine which of the three techniques have the greatest potential for success.