A Critical Interpersonal Distance Switches between Two Coordination Modes in Kendo Matches

Abstract

In many competitive sports, players need to quickly and continuously execute movements that co-adapt to various movements executed by their opponents and physical objects. In a martial art such as kendo, players must be able to skillfully change interpersonal distance in order to win. However, very little information about the task and expertise properties of the maneuvers affecting interpersonal distance is available. This study investigated behavioral dynamics underlying opponent tasks by analyzing changes in interpersonal distance made by expert players in kendo matches. Analysis of preferred interpersonal distances indicated that players tended to step toward and away from their opponents based on two distances. The most preferred distance enabled the players to execute both striking and defensive movements immediately. The relative phase analysis of the velocities at which players executed steps toward and away revealed that players developed anti-phase synchronizations at near distances to maintain safe distances from their opponents. Alternatively, players shifted to in-phase synchronization to approach their opponents from far distances. This abrupt phase-transition phenomenon constitutes a characteristic bifurcation dynamics that regularly and instantaneously occurs between in- and anti-phase synchronizations at a critical interpersonal distance. These dynamics are profoundly affected by the task constraints of kendo and the physical constraints of the players. Thus, the current study identifies the clear behavioral dynamics that emerge in a sport setting.

Herd Those Sheep: Emergent Multiagent Coordination and Behavioral-Mode Switching

“…It also highlights how the lawful dynamics defining rhythmic coordination are largely indifferent to the physical or biophysical properties of the movements involved, as well as the manner of coupling—the coupling can be physical or informational (visually or auditory). Particularly relevant for the current study is recent research demonstrating how similar low-dimensional dynamical processes define a myriad of periodic or semi-periodic multiagent coordination tasks, including interpersonal object movement and collision avoidance tasks (e.g., Mörtl, Lorenz, & Hirche, 2014; Richardson, et al, 2015), competitive sports tasks (e.g., McGarry et al, 2002; Okumura et al, 2012; Yokoyama & Yamamoto, 2012), and improvised social movement tasks (e.g., Zhai, et al, 2014). …”

Self-organized complementary joint action: Behavioral dynamics of an interpersonal collision-avoidance task.

“… 2 Research investigating the dynamics of interpersonal and mutliagent coordination in sport is the exception (see, e.g., Lagarde, Peham, Licka, & Kelso, 2005; Hristovski, Davids, & Araujo, 2006; Okumura et al, 2012; Passos et al, 2009). Also see Mottet, Guiard, Ferrand, and Bootsma (2001) for an example of research examining an interpersonal Fitts Law task.…”

Expertise Differences in Movement Switching in Kendo Players

“…However, player strikes toward the opponent one-sidedly in general kendo practice. Our 47 results suggested that it is essential for players to train focused on acquisition of switching skills in 48 order to further improve their performance. 49…”

“…We conducted repeated-measures two-way analyses of variance, with the 2 groups and 47 3 tasks as factors, on strike time and accuracy. Post-hoc comparisons were conducted using the 48 Bonferroni method. Sphericity assumptions were verified using Mauchly's test.…”

“…Also, in real kendo 8 matches, expert players can accurately perceive the interpersonal distance while moving and can 9 switch their stepping forward and backward movements (Okumura et al, 2012;2017). Even in other 10 sports and physical activities, although researchers have investigated about expertise differences at 11 various viewpoints such as muscle activity (Sakurai and Ohtsuki, 2000) or sensorimotor coordination 12 (Miura et al, 2011), little information about the adjustment and switching skills are available.…”