What Rafael Nadal's success in tennis might have to do with reading direction

Tennis star Rafael Nadal defeats his opponents with his left hand. The Spaniard is currently fighting his way back to the top of the world after a long injury break. He has trained himself to be left-handed and thus benefits from the strategic left-handed advantage: Nadal has already won a Grand Slam tournament eleven times. The Kassel-based sports scientist Prof. Dr. Norbert Hagemann is investigating why left-handed athletes are so successful. The German Research Foundation has now extended the "Laterality in Sports" project by three years. While Hagemann has so far demonstrated advantages of left-handed athletes in decision-making and ball placement behavior, the next phase of the project will focus on the aspect of motor skills - with surprising explanatory approaches. The DFG is supporting the project at the universities of Kassel and Münster with a total of 180,000 euros. "We suspect that most people's motor skills are less well adapted to left-handed players than opponents," explains Hagemann, who works primarily on sports psychology at the University of Kassel. Possible reason: Over the course of a lifetime, most athletes adjust their motor skills to right-handed opponents as they gain more experience with right-handed people. "So in addition to perception, motor skills also adjust accordingly," Hagemann explains. To that end, the scientists plan to conduct a field trial with 30 left- and right-handed amateur badminton players. "We suspect that most people find it easier to hit a ball to the right than to the left," says Hagemann: "In badminton, for example, left-handed athletes benefit from this, because they are much less likely to play on the backhand." The scientists evaluate the rallies via video analysis.

In addition, the scientists want totest the so-called "pseudoneglect" effect; it states that most people perceive stimuli better in the left visual field. This is probably culturally determined, especially by the fact that writing in European languages runs from left to right. In this respect, Nadal's success in tennis could also have something to do with the writing and reading direction of languages in our cultural area. This is verified with an experiment from boxing. "We suspect that athletes are less able to react to left-handed attackers. This is because their punching hand is in the right visual field for them," explains Professor Hagemann. The researchers show test subjects film sequences of a boxer looking head-on into the camera while throwing punches. The video is mirrored at some points so that the boxer punches sometimes with his right, sometimes with his left. The test subjects press a button to indicate when they expect an attack. At the same time, their gaze behavior is recorded. The researchers expected that the test subjects would be significantly less able to anticipate attacks with the left.

The Kassel researchers also suspect that most people's gaze automatically aims toward the opponent's right shoulder. This, they say, is another explanation for why throws or punches that originate from a left hand are worse to predict. That's because if the opponent is left-handed, he's looking at the wrong side. "The mismatched gaze behavior could be one reason why a disproportionate number of left-handed players are at the top of the world rankings, especially in sports where opponents are close to each other and have to react particularly quickly to each other - such as fencing, boxing or table tennis," emphasizes Dr. Florian Loffing, a research associate in the project.

The extended research project follows on from previous studies by scientists from Kassel and Münster. These had already provided evidence that left-handed players have a habitual advantage in sports, even if this is now compensated for in top-level sports by individualized training and precise preparation of the athletes for their next opponent. Laboratory tests confirmed that tennis players, for example, were worse at assessing the strokes of left-handed players than those of right-handed players. It made no difference whether they themselves were left- or right-handed. The researchers from Kassel and Münster are among the few sports scientists in the world to date who are intensively studying laterality in sports, and in particular the left-handed advantage in sports.

Image from the boxer video (Photo: University of Kassel):

www.uni-kassel.de/uni/fileadmin/datas/uni/presse/anhaenge/2013/Boxer.png

Picture of Prof. Dr. Norbert Hagemann (Photo: Uni Kassel):

www.uni-kassel.de/uni/fileadmin/datas/uni/presse/anhaenge/2013/Hagemann_Norbert.jpg

Info:

Prof. Dr. Norbert Hagemann
University of Kassel
Institute of Sport and Sport Sciences
Tel: 0561/804-4494
E-mail: n.hagemann@uni-kassel.de

Dr. Florian Loffing
University of Kassel
Institute for Sport and Sport Sciences
Tel.: 0561/804-4490
E-Mail: f.loffing@uni-kassel.de