研究背景與目的：棒球比賽中可分為守備及進攻兩大部分，過去研究得知比賽時發生運動傷害之機率高於平日練習，但過去資料並無相關防守及進攻時發生傷害之比率，因此本研究的目的在於比較青棒選手在比賽期間進攻與防守時運動傷害發生的比率。方法：本研究由一資深物理治療師以一年時間針對某高中棒球隊36位選手在比賽期間記錄及評估其運動傷害之情形，記錄內容包括比賽時間、守備位置、受傷部位、受傷型態及發生傷害時機（進攻與防守）等，再以卡方檢定比較守備位置、傷害發生時機、受傷部位、及傷害型態之間的差異性。結果與結論：資料收集期間，比賽時間共25天，125個運動小時。運動傷害次數共發生61次，進攻傷害發生率為0.35次／運動小時，防守傷害發生率為0.14次／運動小時。受傷部位以手指／手部的傷害最多，佔32.8%。受傷型態以撞擊最多，佔39.3%。發生傷害的原因以滑壘佔最多(50.8%)。進攻與防守之間傷害發生率有顯著差異(χ^2(下标 (1))=11.95, p<.05)。進攻時以手部／手指及大腿發生次數最多（共22次），受傷型態以撞擊及擦傷／撕裂傷最多（30次），滑壘是進攻時發生受傷的主因（30次）；防守時以手部／手指發生次數最多（9次），受傷型態以撞擊最多（9次），被球打到是防守時受傷主因（13次）。青棒比賽中進攻時發生傷害的機率大於防守時，建議治療人員隨隊比賽時應注意棒球選手進攻時發生的傷害。

Background and Purpose: Baseball game has two parts including offense and defense. Previous studies found that the incidence of baseball related injuries during competition was higher than practice. However, there were no studies about the baseball injuries survey had compare the epidemiological results between offense and defense during baseball competition. The purpose of this study was to analyze the incidence between offense and defense for adolescent players during baseball competition. Methods: This was a prospective, epidemiological study. 36 baseball players were recruited in this study from a high school, in mid-Taiwan for one-year follow-up during competitive. The injuries were collected and documented injury onset (defense and offense), location, type, risk factor and playing position by a senior physical therapist. Chi-square test was used to compare the difference in playing position, injury location and injury site between offense and defense during competition. Results and Discussion: The total competitive hours were 125 and total incidence of injuries was 0.49 times/sports hour. The injury rate in offense was 0.35 times/sports hour and in defense was 0.14 times/ sports hour during competition. The hand/finger was the most complaint location (32.8%). The most common type of injury was contusion (39.3%), followed by lacerations/abrasion (24.6%) and ligament sprain (24.6%). Sliding was the most cause of injuries (50.8%). There was significantly difference between offense and defense at frequency of injuries onset (χ^2(subscript (1))=11.95, p<0.05). Hand/finger was the most frequency of injury location during offense of game. The most frequency of injuries type during offense of competition were lacerations/abrasion and contusion. The cause of injury may be result from sliding during offense of game. During defense of competition, hand/finger was also the most frequency of injury location and the most frequency of injury type was contusion. The cause of injury may be resulted from impact or hit by ball during defense of game. In conclusion, it might have predisposed higher injury rate during offense than defense at competition game. We suggested that the coaches and clinicians may be more careful about the injuries onset at offense.