摘要：Introduction: The rhythmic gymnastics (RG) is a high leap demanding sport (Hutchinson et al., 1998). Leaps are fundamental human movements that require complex motor coordination of both upper and lower body segment. To make it all more interesting and complex, RG leaps performance is almost always followed by a requisite manipulation (the ball, the rope, the hoop, the ribbon, the clubs), and that manipulation is referred to requisite throws or passing through it. In spite of the growing popularity of this Olympic sport, there is a lack of biomechanical analyses in literature, regarding the techniques of rhythmic gymnastics. Aim: The aim of this study was to determine the difference in the certain kinematics parameters, between two types of the leaps, i.e., the front split leap, with the trunk bended backward, and both legs implied in the take off, after the stationary position and front split leap, with the trunk bended backward, and one leg implied in the take off, after the running, which could have an impact on the retention of well-defined "split" form. Method: The study included one subject - Evgenia Olegovna Kanaeva, Russian rhythmic gymnast, actual world champion, the only one in the history of the rhythmic gymnastics, who managed to win six gold medals at the World Championship. The sample of variables consisted of the following kinematics parameters in both types of the leaps: trajectory of the center of gravity of the body (CG) in X and Y axis and the resultant velocity (Vr) of the CG. The data were obtained in the digitizing process, by using the software for kinematics analysis (Hum- an™, Version 5.0, 2005 HMA Technology Inc., Canada). The basic descriptive parameters and statistical significance of differences were determined by using the SPSS 12.0, statistical program for data processing. Results: The absolute frequencies in the Vr of the CG, showed the normal distribution in absolute values of the Vr, in the split front leap, with the trunk bended backward, and one leg implied in the take off, after the running. T-test showed that there was no statistically significant difference (p=.186) in arithmetic mean values in the Vr of the CG, between both leaps, but a statistically significant correlation in the Vr of the CG in the flight phase was determined, in both split leaps (r=. 658, p=.002). Conclusion: The split front leap, with the trunk bended backward, and both legs implied in the take off, after the stationary position, because of its mentioned characteristics, can be considered as energy demanding and more risky for injuries, due to the excessive velocity at the moment of the landing, and with justified greater difficulty in relation to the split front leap, with the trunk bended backward, and one leg implied in the take off, after the stationary position (0.1 point more).
关键词：rhythmic gymnastics; kinematics analysis; front leaps; comparison
