Moderate Effort Instep Kick in Futsal

Abstract

In futsal matches players do not perform maximum kicking effort all the time. There are situations when the player needs to perform a moderate effort kick to achieve certain kicking objectives. In instep kicks, the kicking leg's ankle condition is one of the important parameters influencing the quality of the kick. In maximum effort instep kicks, ankle rigidity is associated with successful kicking effort. This study was focused on the kicking leg's ankle influence on ball velocity during moderate effort kicks in futsal. The focus was on the ankle condition at pre and post impact phase between the foot and the ball. Video analyses were performed on trials of the instep soccer kick with moderate effort to produce low foot velocity during kicking. Seven (n=7) skilled futsal players were selected to perform the kick. Test subject's motions during kicking trials were analyzed by the motion analysis package, Kinovea. The raw data of displacement obtained from the video analysis were then filtered by a single cut-off frequency using 4th order low-pass zero-phase-shift Butterworth filter at 11Hz. Velocity of the ankle and foot before the foot-ball impact and also the ball velocity after the foot-ball impact were calculated from the filtered data using the finite (forward) difference method. Results showed that the ankle influenced kicking outcome. This study also indicated that players focused less on ankle rigidity during ankle-foot plantar flexion during moderate effort kicks. This was based on low ankle-foot velocity ratio prior to ball impact and low coefficient of restitution as compared to maximum kick effort.