![Smečované podání u volejbalistů kategorie kadetů](/api/image/getissuecoverimage?id=picture_2011_48069.jpg)
Smečované podání u volejbalistů kategorie kadetů
The aim of the study was to determine the relationship between jump serve velocity achieved in contact with the ball and a model height of the jump as an indicator of explosive strength of lower extremities and to correlate these values. The monitored group consisted of 169 players (n = 172, age 15.95 ± 0.75 year, body height 185.44 ± 6.9 cm, body weight 71.92 ± 7.92 kg). Before the measurement, the players undertook a jump test, when, in a model situation, they attempted to achieve maximum jump height after a run-up. The highest serve velocity value was 105.9 km.h-1, while the lowest value was 56.3 km.h-1 (difference by 46.8 %). The measured maximum values were transformed into percentile norms (50th percentile P50 = 79.9 km.h-1). Percentile distribution for jump serve velocity and the jump enables us, with respect to a relatively high number of tested players, to consider the stated values as normative and to compare other players, as well. It appears that the correlation of jump height is a good indicator of the dispositions for jump serve implementation in terms of the ball velocity.
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