Abstrakt
Purpose The purpose of this study was to identify the relationship between the speed of instep kick and its accuracy in experienced soccer players. Material and method The monitored group consisted of U19 category soccer teams (n = 20, age = 18.4 +- 0.4 years, body height = 182.7 +- 5.8 cm, body weight = 77.0 +- 6.3 kg).
The ball velocity was recorded using a Stalker ATS radar gun and accuracy of kicking was assessed using 2D kinematic analysis. Results The average speed of the best instep kick trial was 108.8 +- 7.5 km.h-1.
The players achieved high stability of instep kick velocity, when the difference in percentage between the best and worst kick was 6.1 +- 4.6 %. The average distance between the ball and centre of the target was 62.6 +- 28.3 cm in the best trials.
However, concerning kick accuracy, we recorded high variability of accuracy when the average difference between the best and worst trial was 56.8 +- 19.6 %.In case of the fastest kicks, we found a negative trend in the relationship between speed and accuracy r = - 0.17 (p>0.05). On the contrary, in trials with lowest speed there was a positive relationship between the variables r = 0.34 (p>0.05).
Discussions and conclusions Results showed high stability of kicking speed regarding dominant leg. On the contrary, the parameter of kick accuracy revealed high variability.
The research showed that the most accurate kicks were found at speeds between 90-102 km.h-1, which is approximately 80-90 % of maximal kicking speed.