不同重量棒球對投球動作與球速之影響

Effects of throwing different weight baseballs onpitching movement and velocity

前言：本研究目的為探討棒球投手投擲50、75、100、125、150、175、200、225、250、275、300g不同重量棒球，對肩關節外轉角度、屈曲角度與肘關節屈曲角度、球速之影響，以驗證適合投球訓練之棒球重量。方法：使用配置十台紅外線攝影機(200 HZ)的Motion Analysis System 三維動作分析系統，擷取投手投擲十一種不同重量棒球之運動學參數，受試者為五位甲組投手，接受專項訓練時間為9.2±2.17年。結果與討論：(一)投擲100g以下重量棒球會使出手球速顯著提高、最大肩關節外轉發生時機提早、最大肩關節屈曲角度發生時機提早；(二)投擲100g與125g重量棒球會顯著增加約6.15%與4.04%球速，對於投球動作與時序沒有顯著影響；(三)投擲175g重量棒球會減少約0.56%球速，對投球動作各期中的肩關節與肘關節並無顯著影響；(四)投擲175g以上重量棒球會使球速顯著降低、最大肩關節外轉角度變小與發生時機提早。結論：投擲重量介於100g至175g之間棒球不會改變原有的投球動作或投球時序性，且100g至125g棒球可做為增加球速之投球訓練重量，而175g棒球則可做為增加肌力之彈震式訓練的投球重量。

Background: The purpose of this research was to investigate the effects of throwing 50， 75， 100，125， 150， 175， 200， 225， 250， 275 and 300 gram baseballs on pitching velocity， shoulder abduction，external rotation， and flexion angles elbow flexion angle to verify the proper weight that best suitspitching training. Method: Five college pitchers (9.2±2.17 years of training) were analyzed by 3-DMotion Analysis system with ten cameras (200 Hz). Results: The results indicated that (1) throwingless than 100 gram baseball significantly increased pitching velocity and the timing for themaximum shoulder external rotation angle and maximum shoulder flexion to occur became early. (2)Throwing 100 and 125 gram baseballs significantly increased pitching velocity about 6.15% and4.04%， but had no significant influence on pitching movement and timing sequence. (3) Throwing175 gram baseball decreased pitching velocity about 0.56%， but had no significant influence onshoulder and elbow joints during pitching. (4) Throwing more than 175 gram baseball significantlydecreased pitching velocity; moreover， the maximum shoulder external rotation angle becamesmaller and its timing to occur became early. Conclusion: The findings suggested that throwingbaseball weights between 100 to 175 gram would not change pitching posture and timing sequence.Therefore， 100 to 125 gram baseballs are the proper weights for training to increase pitchingvelocity， whereas 175 gram baseball is an appropriate weight for ballistic training to improvemuscle strength.