Coordinative motion of the upper extremity and trunk as a determinant of the spin of thrown ball

2015 Fiscal Year Final Research Report

• Project/Area Number: 25750307
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Sports science
• Research Institution: Waseda University
• Principal Investigator: Nagami Tomoyuki 早稲田大学, スポーツ科学学術院, 助手 (10634371)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: スポーツバイオメカニクス / 野球 / 投手 / 投球動作 / ボール回転 / 肩 / 体幹

Outline of Final Research Achievements

In this study, we analyzed the motion of the upper extremity and trunk of baseball pitchers during pitching. We clarified the relationship between the pitching motion and the spin of the thrown ball. The analyzed data suggested; (1) in comparison with four-seam fastballs, breaking balls can be classified into 3 groups; (2) one of the 3 groups, which includes the types of pitches with different direction of spin axis, equivalent spin rate, and slower ball speed compared with four-seam fastballs (e.g., slider, cutter, and curveball), was thrown by adjusting the angle of forearm supination just before the release, and (3) the inter-day variability in forearm supination angle and the direction of spin axis was observed even when the pitchers threw the same pitch type. These findings would be applicable for the training and conditioning programs for baseball pitchers.

Free Research Field

スポーツバイオメカニクス