Biology subjects

Kizuka, T.

Publications and source records attributed to Kizuka, T..

3 recordsLinked to original sources

bioRxiv2024

Predictive visual patterns during table tennis forehand rallies

The purpose of this study was to clarify predictive visual patterns of skilled table tennis players during forehand rallies. Collegiate male table tennis players (n = 7) conducted forehand rallies at a constant tempo (100, 120 and 150 bpm) using a metronome. In each tempo condition, participants performed a total of 30 strokes (three conditions). Gaze fixation time, gaze targets and saccade eye movements were detected by video footage of an eye tracking device. We found that participants gazed at a ball approaching them only 20 % of the total rally time. Participants tended to gaze at the ball when the opponent hit the ball and move their gaze away from the ball after that. Furthermore, saccades were directed toward the opposite side of the court including the opponent after tracking the ball. These findings suggest that focusing on the opponent motion is important for successful forehand table tennis rallies. Taken together, skilled table tennis players are likely to use unique visual patterns for interceptive sports players to estimate spatiotemporal information about the ball.

physiology↗

bioRxiv2024

The effects of pressure on anticipatory postural adjustments during a jump shot in basketball

BackgroundAnticipatory postural adjustments (APAs) play an important role in feedforward control of dynamic movement, such as jump shot performance in basketball. It is known that jump shot performance declines under pressure from a defender (shot blocker). Research questionDoes pressure from a shot blocker affect APAs of a jump shot in basketball? Is jump shot performance in basketball associated with APAs? MethodsFourteen healthy male university basketball players performed jump shots under pressure and non-pressure (free) conditions by a shot blocker. Using a force plate, the APAs were defined as occurring until the point of thrust (TH) phase, and ground reaction force (GRF) and center of pressure (COP) at that moment were assessed. To assess jump shot performance, the maximum GRF during the TH phase (THmax), jumping height, and success score of the shot (accuracy score: AS) were measured by using the vertical component of the force plate. Two-way ANOVA examined the effects of the phase and condition on APA duration. Pairwise t-tests analyzed pressure effects on subjective pressure intensity, AS, and kinetics measures. Relationships between condition changes in AS and COP or GRF variables were assessed via Pearson correlations. Differences between the pressure and free conditions were denoted by {Delta}. ResultsThe APA duration was shorter under the pressure condition compared to the free condition. The THmax and jump height values were greater under the pressure condition relative to the free condition. Across conditions, changes in COP variables were significantly and negatively correlated with AS. SignificanceThe results of this study suggest that pressure from a shot blocker shortens APA duration and decreases jump shot performance. Additionally, by measuring players APAs and evaluating relationships with jump shooting proficiency, APA variables could potentially serve as indicators of skill expertise.

physiology↗

bioRxiv2023

Importance of head movements in gaze tracking during table tennis forehand stroke

The purpose of this study was to clarify the properties of gaze and head movements during forehand stroke in table tennis. Collegiate table tennis players (n = 12) conducted forehand strokes toward a ball launched by a skilled experimenter. A total of ten trials were conducted for the experimental task. Horizontal and vertical movements of the ball, gaze, head and eye were analyzed from the image recorded by an eye tracking device. The results showed that participants did not always keep their gaze and head position on the ball throughout the entire ball path. Our results indicate that table tennis players tend to gaze at the ball in the initial ball-tracking phase. Furthermore, there was a significant negative correlation between eye and head position especially in the vertical direction. This result suggests that horizontal VOR is relatively suppressed than vertical VOR in ball-tracking during table tennis forehand stroke. Finally, multiple regression analysis showed that the contribution of head position to gaze position was significantly higher than that of eye position. This result indicates that gaze position during forehand stroke could be associated with head position rather than eye position. Taken together, head movements may play an important role in maintaining the ball in a constant egocentric direction in table tennis forehand stroke.

neuroscience↗