Kinematic Analysis of Penalty Kick in Soccer: Effect of Goalkeeper and Target Factor

The purpose of the study was to examine the effects of goalkeeper factor on the kinematics of the penalty kicking in soccer. Five professional players and one goalkeeper voluntarily participated in the study. Accurate penalty shots to fixed targets without and with goalkeeper in goalpost were analysed. Differences between penalty shots performed without and with goalkeeper were compared using a repeated measures analysis of variance (ANOVA). Although no significant difference was found in velocity of anthropometric landmarks for penalty shots with or without goalkeeper, significant differences were found with regard to targets (p<.05). The linear horizontal velocity of the ball (Z axis) were significantly greater in penalty shots to right top corner without goalkeeper than that of right top corner with goalkeeper (p<.05). The linear velocities of anthropometric landmarks except hip were found to be significantly different when before and after contact were evaluated. Significant differences were found with regard to target factor in linear velocity of the center of mass of lower leg and foot (p<.05). The forward linear velocity of the center of mass of lower leg and foot was significantly greater before contact than after contact (p<.05). Knee and ankle joint angles and angular velocities were found to change significantly due to target (p<.05). Consequently, it was revealed that the kinematics of penalty kicking was not affected by existence of the goalkeeper in goalpoast, however, the target of the kick resulted in a significant change in the kinematics of the penalty kicking