Virginia L. Fortney
Virginia L. Fortney and David J. Sanderson
Young-Hoo Kwon, Virginia L. Fortney and In-Sik Shin
Two of the most frequently performed vaults in the 1988 Olympic Games in Seoul were selected for 3-D cine-photogrammetry analysis: the Yurchenko layout with full twist and the Yurchenko layout. The performances included 20 vaults with the highest performance scores: 10 Yurchenko layout with Ml twist (YLF) and 10 Yurchenko layout (YL) vaults, which were performed in the women’s team optional competitions. The YLF group earned higher performance scores than the YL group. Average vaulting times were similar for the groups, but the YLF group showed shorter board and horse contact times and longer postflight times. The projectile motion variables were critical for better performance in the YLF group. Higher vertical velocity at horse takeoff was achieved mainly by minimizing its (Vv) loss during horse contact. The YL group showed the importance of angular momentum for better performance, with the normalized angular momentum during postflight being the critical variable for the YL vault.
Yoshiaki Takei, Erik P. Blucker, J. Hubert Dunn, Scott A. Myers and Virginia L. Fortney
The 20 highest scored handspring with full-turn vaults performed during the 1992 Olympic Games were compared with those receiving the 20 lowest scores. Hypotheses were that the vaults receiving high scores would (a) demonstrate larger horizontal velocity at takeoff from the board and larger vertical velocity at takeoff from the horse and (b) demonstrate greater amplitude of postflight, higher center of gravity (CG) at the completion of the full twist, and superior landing performance than those receiving low scores. Two 16-mm Locam II DC cameras, each operating at a nominal frame rate of 100 Hz, recorded the vaults. It was concluded that the vaults receiving high scores demonstrated (a) larger horizontal velocity and translational kinetic energy at takeoff from the board, larger vertical velocity and translational kinetic energy at takeoff from the horse, and greater amplitude of postflight; (b) greater heights of CG from the beginning of the second-quarter twist to halfway through the third-quarter twist; and (c) superior landing performance than those receiving low scores.