BIOMECHANICAL CHARACTERISTICS OF STAG LEAP WITH BACK BEND OF THE TRUNK: A CASE STUDY

Abstract

Biomechanical considerations as reflected in correct or incorrect technique, particularly in all gymnastic disciplines are more than undoubted. The stag leap as a variation of split leaps is one of the fundamental gymnastics skill and a key movement in the development of elite female gymnasts. The aim of the study was to analyse the kinematic characteristics of the stag leap with back bend of the trunk performed in rhythmic gymnastics and simultaneously find out the explosive power regarding this particular element. A member of Slovakian national team was involved in the study. Kinematic characteristics of the element were analysed. A capture system consisting of 8 infrared cameras were employed to collect the data. The explosive power of the lower limbs were diagnosed by a jump ergometer with 2 standardized tests: vertical counter-movement jump with the fixation of the arms and 10-second repetitive vertical jumps with arms movements. In addition, the explosive power of the lower limbs was also observed in the flight phase of the element. The results in 10-second repetitive jumps show the highest value of gymnast centre of mass 46.4 cm, contact time 0.195 s and the best active output in the flight phase 58.3 W.kg-1. While performing the difficulty element, slightly different data were observed due to the complexity and more demanding motor coordination of both upper and lower body segments: the highest value of gymnast centre of mass was 40.8 cm, contact time 0.209 s and the output in the active flight phase 52.8 W.kg-1.