捕手三種投球動作之運動生物力學分析

Abstract

對一場棒球比賽來說，捕手經常是場上最重要的防守指揮者。而捕手在場上主要的責任為預防壘上的跑者盜壘。一般來說，捕手使用三種投球方式來預防盜壘：分別為throwing from the knees, traditional throw down 與 pitch-out 。本研究目的在比較三種投球動作對關節運動學與球速影響。關節運動學的資料會使用Vicon 紅外線攝影機進行收集，實驗中會有一人投球給補手，捕手接到球後會利用throwing from the knees, traditional throw down 與 pitch-out將球傳至二壘。主要分析的參數包括上肢的關節角度和角速度以及球速。使用重複量數單因子變異數分析和回歸來比較兩種投球方式的差異。結果發現，pitch-out的球速會比 traditional throw down and throwing from the knees還快(p< .05)。而肘關節伸展和軀幹的角速度在兩種投球方式亦有差異。因此，透過捕手投球時的運動學分析，可能有助於幫助我們瞭解如何促進運動表現和避免受傷。

The game of baseball brings together nine individuals to cohesively work together to reach one goal – to win. With a plethora of scenarios that could occur, one critical function of the catcher is to effectively manage base runners. The catcher is often depended on to minimize the opportunities of base runners stealing and advancing into scoring position. Most commonly seen base stealing occurs between first and second base. In contrast to other positions, the catcher makes throws of varying distances during the game, with the longest throws occurring between home and second base as the runner is attempting to steal. Often seen motions utilized by catchers throwing out potential base stealers are throws from the knees, the traditional throw down, and the pitch out. In order to successfully impede stolen bases, the catcher must receive the pitched ball, transfer the ball to the throwing hand, and deliver an accurate throw thirty-eight meters away in less than two seconds. The purpose of this study was to explore and understand inherent differences between the three throwing motions’ joint kinematics when throwing to second base and the effect on performance. 3D-motion analysis cameras captured and yielded kinematic data for the test participants. The pitch out throws generated the fastest ball velocities and total time for the ball to reach second, further substantiating the assumption that the pitch out is in fact the quickest motion to second base. Interpreting and fathoming the results of this study imparts knowledge for plausible training methods to increase performance while possibly reducing the risk of injury.