Investigation of bilateral strength ve balance differences effects related to dominant leg on kicking velocity and accuracy

The aim of this study was to investigate the effects of bilateral strength and balance on kicking velocity and hitting the ball, also whether this effect makes a difference in the right and left leg dominant soccer players. Amateur 34 football players with right dominant legged (age: 21.12±1.85year) and 23 football players with left leg dominant (age: 21.70±2.03year) were voluntery participated to the study. Knee extension and flexion peak torques at 60°.s-1, 180°.s-1 and 300°.s-1 angular velocities of dominant leg (DL) and non-dominant leg (NDL) were tested. Single- and double-leg squat jump (SJ), counter movement jump (CMJ), horizontal jump (HJ), bilateral static and dynamic balances, kicking velocity, hitting the ball, anaerobic power-capacity and agility were also tested. Maximal oxygen consumption (VO2max) was determined indirectly via YO-YO IR test. T test was used for differences within the groups and between the groups. Pearson's correlation analysis was applied to determine whether there was a relationship between test parameters within the groups or not. Probability level was p≤0.05. The results showed that there are significant differences in horizontal jump performances for NDL (p<0.05). Statistical significant differences in isokinetic knee strength values at 60°.s-1 (p<0.05) and also dinamic balance (p<0.01) were observed in NDL. There are significant statistical differences in kicking velocity and hitting the ball for DL. There is a significant relationship just between horizontal jump and kicking velocity performance for both groups (p<0.05). Moderate significant correlation was found between support leg dynamic balance and hitting the ball for DL (r=0.451, p<0.01). As a comparison of the left and right leg dominant soccer players, significant differences were found in CMJ, hamstrings peak torque at 300°.s-1 and H/Q ratio at 60°.s-1 for right DL (p>0.05), but also significant differences were found in DL static balance, NDL dynamic balance and DL hitting the ball for left DL players (p<0.01). As a result, it was observed that horizontal jump was related to kicking velocity more. In terms of the balance, specialization of the players is on dynamic balance and this affected to hit the ball. Left leg dominant soccer players have higher balance and hitting the ball abilities. In conclusion, it is recommended horizontal jumps in plyometric training for kicking velocity, single leg balance and proprioreceptive exercises for hitting the ball abilities. Trainers should encourage young players for using both legs to develop both hemisphers. In addition to this, left dominant leg players should be monitored for strenght imbalance.