Fukuoka Institute of Technology, Faculty of Socio-Environmental Studies, Fukuoka, Japan.
Kitasato University, College of Liberal Arts and Sciences, Sagamihara, Japan.
PLoS One. 2018 Jul 17;13(7):e0200443. doi: 10.1371/journal.pone.0200443. eCollection 2018.
Successful baseball hitting involves a combination of highly trained perceptual skills and forceful bat swing motions. The purpose of the present study was to quantify the horizontal movement of the head and eyes while baseball batters hit a fastball to clarify a visual strategy for this highly trained interceptive task. Six collegiate baseball players hit a fastball that was launched from a pitching machine. The ball speed was 31.9 m·s-1 for the Slow Ball Task and 40.3 m·s-1 for the Fast Ball Task. Horizontal head movements were analysed using images that were captured by two high-speed video cameras. The Horizontal eye movement was recorded with electrooculography. The angular speed of the horizontal head and eye movements during hitting were divided into four time periods (I-40 = 21-40% of total ball-flight, I-60 = 41-60% of total ball-flight, I-80 = 61-80% of total ball-flight, I-100 = 81-100% of total ball-flight) and analysed using analysis of variance and a Tukey post-hoc multiple-comparison. In the Slow Ball Task, the horizontal angular velocity of the head during I-80 was significantly faster than that during I-40 (p < 0.05). In the Fast Ball Task, the horizontal angular velocity of the head during I-80 was significantly faster than that during I-40 and I-60 (p < 0.05). These results indicated that the tracking motion of the head became faster as the launched ball came close to the batters, but there was no change in the angular tracking motion of the eyes. Therefore, rapid eye movement may not be suitable to accurately estimate the ball's future location during fastball hitting based on the eye-centered coordinates. Our findings suggest that conventional vision training with a wide range of saccadic or smooth-pursuit eye movements does not reflect the characteristics of tracking strategies during baseball hitting.
成功的棒球击球涉及高度训练的感知技能和有力的球棒挥击动作的结合。本研究的目的是量化棒球击球手击球时头部和眼睛的水平运动，以阐明这项高度训练的拦截任务的视觉策略。六名大学生棒球运动员用投球机击出一个快球。球速在慢球任务中为 31.9 m·s-1，在快球任务中为 40.3 m·s-1。使用两台高速摄像机拍摄的图像分析头部的水平运动。使用眼电图记录水平眼睛运动。击球时头部和眼睛的角速度被分为四个时间段（I-40 = 总球飞行的 21-40%，I-60 = 总球飞行的 41-60%，I-80 = 总球飞行的 61-80%，I-100 = 总球飞行的 81-100%），并使用方差分析和 Tukey 事后多重比较进行分析。在慢球任务中，I-80 期间头部的水平角速度明显快于 I-40 期间（p<0.05）。在快球任务中，I-80 期间头部的水平角速度明显快于 I-40 和 I-60 期间（p<0.05）。这些结果表明，随着投出的球接近击球手，头部的跟踪运动变得更快，但眼睛的角跟踪运动没有变化。因此，基于以眼睛为中心的坐标，快速眼球运动可能不适合准确估计快球击球时球的未来位置。我们的研究结果表明，传统的包含广泛扫视或平滑追踪眼球运动的视觉训练并不能反映棒球击球时的跟踪策略特征。
