Hitting movement patterns organized by different pitching movement speeds as advanced kinematic information.

Conventionally, hitting movements in response to different advanced kinematic information have been investigated from the perspective of chronometric analysis, such as measuring the timing of movements. This is the first study to investigate the effect of manipulating advanced kinematic information on the hitting movement pattern organization based on both kinematics and kinetic analyses in addition to the conventional chronometric analysis. Specifically, the hitting movement of experienced batters in response to visual stimuli consisting of different pitching movement speeds with the same ball trajectory information was measured by an optical motion capture camera system and a foot force sensor inside the shoes. The occurrence timings of specific events (e.g., movement initiation), some kinematic parameters (e.g., maximum rotate angle of the shoulder and hip), and the balance of the ground reaction force between the ball of the big and small toes of both feet were compared between experimental conditions. This was done to test the hypothesis that the hitting movement is coupled with the visual information given to batters based on an expert anticipatory model. The results indicated that for a faster pitching speed, the batter tended to react with a significantly smaller preparatory movement (e.g., smaller weight shift and shoulder rotate angle during backswing) and put significantly larger weight on the rear foot during the swing execution phase. The situation was exactly reverse in the case of a slower pitching movement. These results suggest for the first time that manipulating advanced kinematic information not only affects the timing of the movement, but also the whole-body kinematics and lower body kinetics. The results also indicate that the hitting movement pattern of experienced batters is highly dependent on the advanced kinematic information.