目的：比較棒?球?前式與?後式?種?同?上起跑方式之運動學和動?學上的差?。方法：以中華??國家代表隊15名野手為研究對象，?用?台Sony?位攝影機(60Hz)與單軸加速規(1000Hz)與一台AMTI測?板(1000Hz)。同步擷取?種?同?上起跑動作影像，以APAS分析軟體獲取跑?時間和??瞬間速?等運動學??。動?學以Acqknowledge3.5.2版軟體分析??瞬間的推進?最大??、推進?衝?、垂直最大??及垂直衝?等??並除以個人體重(BW)作為標準化。所得?據以相依樣本t考驗進?統計分析，α定為.05。結果：?後式在總跑?時間(3.19±0.11 sec vs.3.28±0.14 sec)、??瞬間速?(2.17±0.15m/s vs. 2.04±0.25m/s)、水平推進?衝?(0.03±0.014m/s vs. 0.02±0.012 m/s)、垂直最大??(1.01±0.33Nt/BW vs. 0.53±0.34Nt/BW)及垂直衝?(0.19±0.068m/s vs. 0.08±0.048m/s)等??上均顯著優於?前式(p<.05)。結?：整體而言，?後式較?前式可明顯縮短跑?時間，但因??時機上的差?，造成有5名受試者(C.D.F.J.L)在總跑?時間上?前式快於?後式，因此建議此5名受試者(C.D.F.J.L)宜採?前式起跑方式，其餘受試者在能有效掌握??時機下建議?球選手在所有?包跑?時以及棒球選手在三?高飛犧牲打時，?上起跑動作可採用?後式，以取得較佳的時間優勢，提高跑者安全上?的機?。

This study examined the kinematics and kinetics differences between the two kinds of baserunning starts, base-back and base-front starts, in baseball and softball. The subjects are fifteen players of the National Chinese Taipei Women's Softball Team (age=22.47±3.02yrs, weight=62.13±10.31kg, height=163.47±5.79cm, softball experience =10.00±2.56yrs). Two Sony 60Hz digital cameras and a synchronization of one-axial acceleometer (1000Hz) with a AMTI force platform were used for filming the two baserunning starts. All films were analyzed, filtered and linear-converted by ariel performance analysis system to obtain the baserunning time as well as the velocity of take-off. The force signals received by the Acknowledge 3.5.2 software were then analyzed and calibrated to get parameters of the maximum propulsive force, the propulsive impulse, the maximum vertical force and the vertical impulse. The resultant parameters were divided by individual bodyweight (BW) as the normalizer. The data were statistically analyzed with descriptive statistics and a paired sample t-test (α=0.5). The result indicated that base-back start is significantly better in baserunning time (3.19±0.11s vs. 3.28±0.14s), velocity of take-off (2.17±0.15m/s vs. 2.04± 0.25m/s), the propulsive impulse (0.03±0.014m/s vs. 0.02±0.012 m/s), the maximum vertical force (1.01±0.33Nt/BW vs. 0.53±0.34Nt/BW) and vertical impulse (0.19±0.068m/s vs. 0.08±0.048m/s) than the base-front start (p＜.05). Because the base-back start saves more baserunning time than the Base-Front start, we suggested that softball players in all kinds of baserunning situations as well as the baseball players encountering the third-base outfield sacrifice fly adopt the base-back start for a better time advantage and a greater chance to reach the base safely.