Evaluation of soccer kick tecniques in different age groups with kinetic and kinematic methods

In this research, it is aimed that analysing differences of ball velocity, isokinetic strength and leg mass parameters and kinetic, kinematic and electromyography parameters which occur in the kicking and supporting leg between 3 different age groups (12-13, 14-15,16-17). 10 soccer players volunteered to participate the current study from each group. The kicking and supporting leg isokinetic strength measurement have done with 60 ve 180 °sn-1 angular velocity and leg mass calculated by Hanavan modell. Ball velocities tested by a radar gun. Meanwhile, electromyography, high speed camera and force plate data? were recorded syncronizely. Muscular activation of kicking leg tibialis anterior, gastrocnemious, rectus femoris, vastus lateralis, vastus medialis, biceps femoris, gluteus maximus, gluteus medius muscles and supporting leg tibialis anterior, gastrocnemious, vastus lateralis and gluteus maximus muscles have measured by using EMG. Kicking leg, hip, knee, ankle angle and angular velocities and shoulder, hip, knee, ankle and 5th metatarsal finger anterior-posterior axis, velocities with knee vertical axis velocity and shoulder and ankle medio-lateral axis velocities were analysed by using high speed cameras. Furthermore, ground reaction forces of support foot from Fx, Fy and Fz axis were analysed. One way ANOVA was used for statistical analyses and Post hoc Tukey test was performed in order to analyse differences between three different age groups in the case of in-step kick ball velocity, isokinetic strength values, leg mass values and angles, angular and linear velocities of joints. According to ball velocity, isokinetic strength and leg mass values, all parameters demonstrate linear increase with age and statistical significant differences (p<0.05; p<0.01) observed between groups. With regard to muscular activation patterns, statistical significant differences (p<0.05) were observed in rectus femorsi, vastus medialis and biceps femoris muscles between groups. The muscular activation of 16-17 age group found higher than other groups for the rectus femoris in leg cocking, the vastus medialis activation in forward swing and biceps femoris activation in ball contact and follow through phases. According to motion analyses results, hip angle, knee angular velocity and hip, knee, ankle and finger linear velocities increases linearly with age and shows statistical significant differences (p<0.05; p<0.01) between groups. Moreover, in terms of support leg ground reaction force in vertical axis (Fz) demonstrate statistical significant differences (p<0.05) between groups and 16-17 age group values found higher in ball contact than other groups. As a result, ball velocity increases with chronological age increase, furthermore, strength parameters and kinetic and kinematic parameters and muscular activation patterns related to ball velocity increases. Especially it could be said that 16-17 age group has developed better muscular cordination and used tension arc mechanizm better than the other age groups. Key Words: Soccer, Electromyography, Motion analyses, Force plate, In-step kic