ANALYSIS OF CORRELATION BETWEEN SELECTED KINEMATIC VARIABLES OF THE TAKE-OFF AND THE LENGHT OF THE SKI-JUMP

Abstract

The objective of the study was to establish, by means of 2-D kinematic analysis, the correlation between selected kinematic parameters of the take-off of the jumpers and their performance from the aspect of the jump length on a sample of the best ski jumpers (first series n = 42; second series n = 30) participating in the final competition of the World Cup in Ski Flights at Planica in 1999 (K 180 m). Analysis of correlation and single-factor analysis of variance were used. A smaller number of statistically significant correlations between the defined kinematic variables and the jump length was determined. The differences in the vertical velocity of the take-off on the edge of the take-off platform confirmed a tendency towards positive correlations between this variable and the jump length (the group of the best ski jumpers attained the smallest vertical velocity in both jumps; in the first jump, the differences between the various quality groups of ski jumpers were statistically significant. The best group of ski jumpers showed tendencies towards a more pronounced transfer of the hips and the common centre of gravity in the forward direction (the take-off rotation factor) relative to the axis of the ankle (the differences between the various quality groups of ski jumpers were statistically significant in the second jump).