在球類運動中球是最重要的器材之一，它可以做為雙方球隊對抗的中介物，並促使球員集中 注意力。當球體受外力撞擊的狀況下，球速的變化是我們能夠獲得的第一訊息，亦代表著球體的 動態力學特質。此外，球體在碰撞時所產生形變，會使得能量在壓縮與回彈的循環中產生損耗並 造成了反彈與球速的變化，進而直接影響球員的運動表現。球體的彈性同時受到許多因素的影 響，透過實際量測的方式來分析動態的力學特徵，藉此除了能夠獲得真實的球體彈性變化，亦能 避免推估錯誤的情形，以便進行更進一步的估計與模擬。在運動訓練上，教練與選手可透過先行 了解球體的力學特性，再適當改變球體質量或是大小，以便有效且正面的幫助運動員的學習以及 技術表現。

In ball games, the ball is one of the most important equipments which mediate confrontation in team sports and attract the athletes' attention. The ball velocity is the message which represents one of the dynamitic properties during the collision. In addition, the ball will be deformed by impacting and the energy is stored and lost in the ball body for a complete compression and expansion cycle. Thus, the ball bounce and velocity affect the performances of the players during play. The ball bounce was influenced by many factors. At present, the researchers usually measure or analyze the dynamic mechanical properties directly under a controlled condition to avoid underestimating for further evaluations and simulations. Therefore, the coaches and athletics should comprehend the mechanical properties of the balls before training and modification on diverse game balls appropriately to advance in motor learning and improve the performances.