A 'kickout' double salto backward tucked dismount from the horizontal bar performed by elite gymnasts

The aim of this study was to identify the differences in the tucked and extended body positions, and in the spatiotemporal characteristics of the motion of the centre of mass, during the performance of kickout and non-kickout double salto backward tucked dismounts. A 16-mm camera, operating at 100 Hz, was used to record double salto backward tucked dismounts during the 1990 national championships in Japan and the USA. A high-scoring kickout group (n = 24) had a significantly (P < 0.005) higher body centre of mass at the tightest tuck position in the first salto, and shorter time to achieve maximum body extension during the second salto, than did a low-scoring non-kickout group (n = 24). Furthermore, the kickout group showed greater height of body centre of mass, larger normalized moment of inertia, and smaller body angle from the vertical at maximum body extension. Consequently, they had longer duration and larger distances of flight than the non-kickout group in which to display the maximum body extension before landing on the mat. It was concluded that the kickout double salto backward tucked dismount is indeed more effective than the non-kickout dismount because it involves (a) greater body extension in an inverted position before passing through the vertical and (b) greater heights of centre of mass at the peak of flight, at the tightest tuck and at maximum body extension. Furthermore, this dismount enhances the display of virtuosity for which bonus points are awarded. The results suggest that this kickout dismount may be helpful in developing the mechanical foundation necessary for learning more advanced dismounts, such as the triple salto backward tucked and double salto backward stretched, with increased effectiveness and safety.