KINESTHETIC EXPERIENCE IN PENALTY TRAINING

Faced with a shot on goal, the goalkeeper not only needs to coordinate his perception with his own action, but also his action with that of the kicker. For this, it is key to develop the ability to “read” the rival’s actions and the intentions behind them. From predictive processing theory comes the notion that, in order to interpret another person’s intention to act, one needs to have a rich kinesthetic experience of that action; that is, how a certain movement feels in one’s own body.

In this context, researchers from the Departments of Psychology and Human Movement Sciences at the Universities of Amsterdam and Rotterdam (The Netherlands) tested the hypothesis that the kinesthetic experience of a goalkeeper in taking penalty kicks allows him/her to predict more effectively the direction of the opponent’s shot and improve the chances of avoiding the goal.

For the experiment, they recruited 51 goalkeepers from high-level amateur soccer clubs and goalkeeper training centers in the Netherlands, aged 16 years or older (mean 22.8 years) and with a minimum of 3 years of active experience in an amateur or (semi-)professional football team participating in a Royal Dutch Football Association competition.

Goalkeepers were assigned to three groups: (1) penalty blockers (PB), that practiced only penalty blocking, (2) penalty kickers (PK), that only took penalties, and (3) control group (C), that ran 80-meter sprints and practiced keeping the ball in the air for as long as possible, using different body parts, except their arms and hands.

The goalkeepers of the PB and PK groups were grouped in pairs, but performed individually. One always kicked and never blocked, while the other always blocked and never kicked. Pairs were formed based on experience level, whether they were first or second goalkeeper in their teams, and age.

After practicing these activities for a period of time, the goalkeepers performed a task on a laptop to test their shot direction anticipation skills. They watched videos showing a player running towards the ball to take a penalty kick on a regular footbal pitch. The videos were recorded from the goal line to represent the goalkeeper’s perspective. At the moment the shooter’s foot touched the ball, the video stopped and (with a fade time of 0.5 s) the screen turned green. The goalkeepers then had to predict the direction of the ball by pressing one of four buttons that referred to one of four possible sections in the arc seen on screen: right/left and low/high. Instructions focused on accuracy and speed of response, as diving in the right direction would not save a goal if it occurred too late. Accuracy was defined as the percentage of responses in which the selected button corresponded to the actual direction of the shot. Reaction time was measured as the interval (in milliseconds) between the moment the kicker contacted the ball and the moment the participant pressed the button.

Accuracy averaged 51.3%, which is well above the probability level (25%), indicating that the participants were able to predict the direction of the shot reasonably well from the videos. As shown in the graphic, accuracy improved for the PB and PK groups, but not for the control group. Results revealed that after only 20 minutes of training, practicing penalty kicks improved reading accuracy by 4.5%. Regarding this data, the authors suggest that, considering that professional goalkeepers in the German Bundesliga block 18.8% of all penalty kicks, an increase of 4.5% would be significant and could mean the difference between winning and lose a match or a tournament. Response speed averaged 664 ms and reaction time improved from pre-test (691 ms) to post-training (636 ms), but the effect of training did not differ between groups.

Interaction of Group (X-axis) and Time (separate bars/violins) effects on penalty kick reading accuracy (Y-axis). Accuracy improved from pretest to posttest for the PB and PK training groups, but not for the control group.

The authors point out that responding after the ball has been hit leaves the goalkeeper with very little time to get to it before it crosses the goal line. Reading the kicker’s movements during setup and during the shot can give the goalkeeper an early advantage and increase his chance of blocking the shot. In this context, the authors conclude that their results open a scenario to expand the goalkeepers’ training strategies, increasing their experience by shooting penalties. But they also comment that although the goalkeepers tested in this experiment were experienced high-level amateurs, it remains to be established whether the improvements extend beyond the experimental setting and whether professionals in national football competitions would also benefit from taking penalty kicks as for training.