Department of Health Science, Kinesiology, Recreation and Dance, University of Arkansas, Fayetteville, Arkansas, USA.
J Strength Cond Res. 2010 Sep;24(9):2366-71. doi: 10.1519/JSC.0b013e3181b22aea.
This study examined forearm pronation in relation to both the vertical and horizontal ball movement measured for 2 variations of the fastball pitch. Ten healthy collegiate baseball pitchers participated in the study (age: 19.4 +/- 0.7 yr, height: 1.90 +/- 0.06 m, mass: 88.50 +/- 9.05 kg). Reflective markers were placed at the level of each joint center's location, and standard high-speed video techniques were used to record the participants as they threw 10 maximal effort fastball pitches. Marker positions were digitized in each video frame from which forearm pronation data were calculated. Across all pitchers, magnitude of both the vertical and horizontal ball movement was observed to be greater for the 2-seam fastball than for the 4-seam fastball. Regardless of pitch type, positive relationships were observed between all forearm pronation parameters and both vertical and horizontal ball movement. A significant positive correlation (r = 0.583, p < 0.01) was identified between forearm pronation acceleration at ball release and the magnitude of vertical ball movement regardless of pitch type. These results suggest that pitchers may be able to manipulate the magnitude of vertical ball movement by altering pronation accelerations at ball release. In addition, it appears that pitchers should alter their current training techniques so as to increase the endurance capabilities of the primary pronator muscles of the forearm. In doing so, they may be able to limit the effects of fatigue on these muscles during pitching, thus preventing a decrease in the magnitude of vertical ball movement that typically occurs late in a pitching performance.
本研究考察了与垂直和水平球运动相关的前臂旋前，这两种运动是在两种快球投球方式下测量的。10 名健康的大学生棒球投手参与了这项研究（年龄：19.4 +/- 0.7 岁，身高：1.90 +/- 0.06 米，体重：88.50 +/- 9.05 公斤）。在每个关节中心的位置放置反射标记，并用标准高速摄像技术记录参与者投掷 10 次最大努力快球的情况。在每个视频帧中数字化标记位置，从这些位置计算前臂旋前数据。对于所有投手，无论是 2 缝快球还是 4 缝快球，垂直球和水平球的运动幅度都更大。无论投球类型如何，所有前臂旋前参数与垂直和水平球运动都呈正相关。在球释放时，前臂旋前加速度与垂直球运动幅度之间存在显著的正相关关系（r = 0.583，p < 0.01），与投球类型无关。这些结果表明，投手可以通过改变球释放时的旋前加速度来操纵垂直球运动的幅度。此外，投手似乎应该改变他们目前的训练技术，以增加前臂主要旋前肌的耐力能力。这样，他们可以在投球过程中限制这些肌肉疲劳的影响，从而防止垂直球运动幅度的下降，这种下降通常发生在投球表现的后期。
