PRE-FLIGHT MECHANICAL DIFFERENCES BETWEEN TWO HANDSPRING CATEGORY VALUTS PERFORMED BY ELITE GYMNASTS

Abstract

The handspring (HS) vault forms the basis for mastering the more advanced handspring and salto forward tucked (HSS) vault, which in turn provides the basis for learning the handspring and double salto forward tucked (Roche) vault with greater ease and safety. The Roche is one of the most advanced and high-risk vaults seen in major competitions today. Pre-flight mechanical variables have important “causal influence” on the subsequent phases and overall performance of the vault. Therefore, the purpose of this study was to identify the pre-flight mechanical variables that are crucial in achieving successful transition from the HS vault to the HSS vault. The subjects were 40 male gymnasts performing the HS vault at the 1987 Pan American Games and 51 male gymnasts performing the HSS vault at the 1988 Olympic Games. The vaults were filmed using a 16-mm camera operating at 100 Hz. Approximately 50 frames were digitized for each vault. A theoretical model was developed to identify the mechanical variables that determine the linear and angular motions of the vaults. The results of t test applied to the data indicated that the HSS vault, compared to the HS vault, had significantly (P < .005): (1) greater horizontal velocity and higher body center of mass (CM) at touchdown (TD) on the board; (2) greater horizontal displacement of body CM and smaller change of the vertical velocity while on the board; (3) greater horizontal velocity, greater normalized angular momentum, and higher body CM at take-off (TO) from the board; (4) smaller horizontal and vertical displacements of body CM, shorter time, and greater angular speed of pre-flight; and (5) greater vertical velocity and lower body CM at TD on the horse. In conclusion, successful transition from the HS vault to the HSS vault is likely when the focus is on achieving: (1) large horizontal velocity at TD on the board by sprinting the approach and departing from it with large horizontal velocity and normalized angular momentum; (2) small horizontal and vertical distances traveled by CM, short time, and rapid body rotation in pre-flight by reaching toward the far-end of the horse with the hands (flexion of the humerus) as quickly as possible upon TO from the board; and, consequently, (3) large vertical velocity and low body CM at TD on the horse to effect successful on-horse and post-flight performance.