Graduate Institute of Sports Equipment Technology, Taipei Physical Education College, Taipei, Taiwan.
J Strength Cond Res. 2011 Nov;25(11):2999-3005. doi: 10.1519/JSC.0b013e318212e3b8.
The purpose of this study was to investigate the effects of the 8-week dynamic moment of inertia (DMOI) bat training on swing velocity, batted-ball speed, hitting distance, muscle power, and grip force. The DMOI bat is characterized in that the bat could be swung more easily by reducing the moment of inertia at the initial stage of swing without decreasing the bat weight and has a faster swing velocity and lower muscle activity. Seventeen varsity baseball players were randomly assigned to the DMOI bat training group (n = 9) and the normal bat training group (n = 8). The training protocol was 7 swings each set, 5-8 sets each time, 3 times each week, and 8 weeks' training period. The results showed that the swing training with the DMOI bat for 8 weeks significantly increased swing velocity by about 6.20% (96.86 ± 8.48 vs. 102.82 ± 9.93 km·h(-1)), hitting distance by about 6.69% (80.06 ± 9.16 vs. 84.99 ± 7.26 m), muscle power of the right arm by about 12.04% (3.34 ± 0.41 vs. 3.74 ± 0.61 m), and muscle power of the left arm by about 8.23% (3.36 ± 0.46 vs. 3.61 ± 0.39 m) (p < 0.05). Furthermore, the DMOI bat training group had a significantly better change percentage in swing velocity, hitting distance, and grip force of the left hand than did the normal bat training group (p < 0.05). The findings suggested that the swing training with the DMOI bat has a positive benefit on swing performance and that the DMOI bat could be used as a new training tool in baseball.
本研究旨在探讨 8 周动态转动惯量（DMOI）球棒训练对挥棒速度、击球速度、击球距离、肌力和握力的影响。DMOI 球棒的特点在于，在挥棒的初始阶段，通过减小转动惯量，使球棒更容易挥动，而不会降低球棒的重量，从而使挥棒速度更快，肌肉活动度更低。17 名大学棒球运动员被随机分配到 DMOI 球棒训练组（n = 9）和普通球棒训练组（n = 8）。训练方案为每组 7 次挥棒，每次 5-8 组，每周 3 次，共 8 周训练期。结果表明，用 DMOI 球棒进行 8 周的挥棒训练可显著提高挥棒速度约 6.20%（96.86 ± 8.48 比 102.82 ± 9.93 km·h(-1)），击球距离约 6.69%（80.06 ± 9.16 比 84.99 ± 7.26 m），右臂肌力约 12.04%（3.34 ± 0.41 比 3.74 ± 0.61 m），以及左臂肌力约 8.23%（3.36 ± 0.46 比 3.61 ± 0.39 m）（p < 0.05）。此外，DMOI 球棒训练组在挥棒速度、击球距离和左手握力的变化百分比方面明显优于普通球棒训练组（p < 0.05）。研究结果表明，DMOI 球棒挥棒训练对挥棒表现有积极的影响，DMOI 球棒可作为棒球训练的新工具。
