How wide should you view to fight? Establishing the size of the visual field necessary for grip fighting in judo

Abstract

Peripheral vision is often considered vital in (combat) sports, yet most experimental paradigms (e.g., eye tracking) ignore peripheral information or struggle to make inferences about the role of peripheral vision in an in-situ performance environment. This study aimed to determine where visual information is located in the peripheral field during an in-situ combat sports task. Eight advanced judokas competed in grip-fighting exchanges while wearing a mobile eye-tracker to locate gaze direction. Threedimensional position data of the head and hands were tracked using a VICON motion capture system. Gaze analysis through automatic feature detection showed that participants predominantly fixated on their opponent's chest. Kinematic data were used to calculate the angles between the opponent's hands and the gaze-anchor point on the chest of the opponent. Results revealed a nonlinear relationship between visual field (VF) size and visibility of the hands, with athletes needing a VF of at least 30-40 degrees radius to simultaneously monitor both hands of the opponent most of the time. These findings hold implications for the regulation of Paralympic judo for athletes with vision impairment, suggesting that a less severe degree of impairment should be required to qualify than the current criterion of 20 degrees radius.

Eye-tracking technology and the dynamics of natural gaze behavior in sports: an update 2016–2022

“…However, for three of the total five studies with an algorithmic GCA, the automation was at the expense of accepting a stationary collection of gaze data ( Spitz et al, 2016 ; Hunfalvay and Murray, 2018 ; Kim et al, 2019 ). Still, the remaining two studies with a completely automated GCA ( Goh et al, 2018 ; Krabben et al, 2022 ) represent significant progress in terms of algorithmic analyses of mobile eye-tracking data in sports-related settings (from 0% in 2017 to 8.0% more recently).…”

A scoping review on Para Judo

“…The International Blind Sports Federation has considered this suggestion, announcing that after the Tokyo 2020 Paralympic Games in 2021, athletes will compete in two classes (one for blind and another for partially sighted judokas). 67 Thus, because of findings from different investigations, [8][9][10][11][12] the new IBSA Judo Classification Rules 7 were published in 2022 and established two sport classes: J1 for blind and J2 for partially sighted judokas. The work of Krabben et al [8][9][10][11][12] has allowed determining the cutoff points in each sport class based on visual acuity and visual field.…”

“…67 Thus, because of findings from different investigations, [8][9][10][11][12] the new IBSA Judo Classification Rules 7 were published in 2022 and established two sport classes: J1 for blind and J2 for partially sighted judokas. The work of Krabben et al [8][9][10][11][12] has allowed determining the cutoff points in each sport class based on visual acuity and visual field. In addition, athletes no longer compete altogether.…”

“…The boundaries between the two sport classes are established by considering the athletes' acuity and visual field. The scientific evidence derived from the work of Krabben et al [8][9][10][11][12] has helped IBSA to set these boundaries. Thus, in J1, the athlete's vision impairment must result in visual acuity of less than or equal to LogMAR 2.6 in binocular vision, and in J2, the athlete's visual acuity must be within a range between LogMAR 1.3 and 2.5 with binocular vision or with a binocular visual field of 60 degrees or less in diameter.…”

Naturalistic Decision-Making in Sport: How Current Advances Into Recognition Primed Decision Model Offer Insights for Future Research in Sport Settings?

“…As pointed by Macquet ( 2020 ), relevant cues were context-specific and were mostly concerned with visual perception. Today the field of visual search strategies is fertile among athletes (Vater et al, 2019 ; Krabben et al, 2022 ), referees (Luis del Campo et al, 2018 ; Moore et al, 2019 ) or coaches (Robertson et al, 2018 ; Mitchell et al, 2020 ). New methodological designs need to be proposed in order to study the visual information that is prioritized by experts in situation recognition and intuitive decisions in more ecological conditions (i.e., naturalistic conditions).…”