棒球與快速壘球是極相似的運動，在臺灣許多壘球教練皆為棒球轉任，但異於棒球投手的快壘投球法，如何在訓練上正確的轉換，過去文獻中並無詳細探討。本篇彙整棒球與快壘球投球之實證性研究，從運動生物力學觀點中說明出兩者在投球時的不同，提供壘球選手與教練在訓練時應注意的地方，選擇適合該項選手投球練習之方法，以提升投球表現並避免運動傷害。事實上，棒球與快壘投手投球時皆由跨步著地，以地面反作用力與身體的扭轉將球投出，但兩者間僅有手臂減速期與跟隨動作期時較相似，而在準備抬腿、跨步期、手臂上舉期與手臂加速期時兩者之間差異較大。此外，壘球不像棒球有投手丘的高度落差，在沒有重力加速度幫助及投擲臂力量有限的影響下，下肢產生的作用力也形成差異。因此，在訓練上建議分為手臂動作與下肢動作來進行，在手臂部分須提升選手擺臂轉動速度來增加轉動慣量，而在下肢方面，將重點擺在學習跨出著地動作時須保持平衡，來增進投球的穩定度。

Many softball coaches are originally transformed from baseball coaches in Taiwan because the two sports are very familiar. However, past studies rarely discussed the difference between baseball and softball. The study surveyed many papers from past empirical studies about the two sports to find out the differences and provided athletes and coaches of softball with important ideas about training and injury. In fact, there are only two motion periods which are arm deceleration and follow-through to be similar between the two sports. Other periods like preparing, stepping, arm rising up and arm acceleration are different. In addition, because there is no pitching grave mound for softball pitchers, they can't get energy from the gravity power. Therefore, the power generated from the lower extremity is different between the two sports. Therefore, we suggested the pitchers' training should be divided into two parts which were arm and lower extremities motion. The pitchers of softball should speed up the velocity of arm rotation to add rotation inertia. In addition, the pitchers also should keep balance when they learned to step forward.