This study delineates the common characteristics of pitching motion in professional baseball players (Top and Minor groups) by focusing on their upper body. With an aim to gain insight into the development of athletic abilities, the pitching motion of the Top group was compared with the Minor group, resulting in the clarification of upper limb issues in the Minor group and amateur pitchers. The subjects were 47 pitchers belonging to the Nippon Professional Baseball (NPB). The experiment was a fastball pitch with maximum effort. The analyzed trial was the highest ball velocity (average ball velocity 38.9 ± 1.8 m/s). Post-analysis, the following commonalities and differences were identified. (1) There is a commonality in the sizeable external rotation of the shoulder joint during MER (Maximum External Rotation), which is considered a factor in pitching speed compared to amateur pitchers. However, after evaluating the professional baseball pitchers, it was suggested that this movement had a low influence on the ball velocity. (2) There was a commonality in the movements in which the maximum shoulder horizontal adduction angular velocity was more significant than the upper trunk angular velocity. (3) However, in terms of differences among professional baseball pitchers, the Top group pitchers had a greater horizontal adduction angular velocity of the shoulder joint during MER and a more significant extension angular velocity of the elbow joint during REL (Ball Release) by suppressing the forward tilt angular velocity of the trunk during MER.
