Fleisig Glenn S, Kingsley David S, Loftice Jeremy W, Dinnen Kenneth P, Ranganathan Rajiv, Dun Shouchen, Escamilla Rafael F, Andrews James R
American Sports Medicine Institute, 833 St. Vincent's Drive, Suite 100, South Birmingham, AL 35205, USA.
Am J Sports Med. 2006 Mar;34(3):423-30. doi: 10.1177/0363546505280431. Epub 2005 Oct 31.
Controversy exists about whether breaking pitches are more stressful than are fastballs. Previous biomechanical studies compared kinematics but not kinetics.
Elbow and shoulder forces and torques are statistically different among the fastball, curveball, change-up, and slider.
Descriptive laboratory study.
Twenty-one healthy collegiate pitchers were studied with a high-speed automated digitizing system. All subjects threw fastballs (n = 21), most threw curveballs (n = 20) and change-ups (n = 19), and a few threw sliders (n = 6). Wrist, elbow, and shoulder kinetics were calculated using inverse dynamics. Nine kinetic and 26 kinematic parameters were compared among the different pitch types using repeated-measures analysis of variance.
At the shoulder, internal rotation torque, horizontal adduction torque, abduction torque, and proximal force were significantly less in the change-up than in the other 3 pitches. Shoulder horizontal adduction torque was greater in the fastball than in the curveball and slider. Shoulder proximal force was greater in the slider than in the curveball. Elbow proximal force was less in the change-up than in the other 3 pitches. Elbow varus torque was greater in the fastball and curveball than in the change-up. Elbow flexion torque was greater in the curveball than in the change-up. The curveball and change-up demonstrated kinematic differences from the fastball, consistent with previous studies.
There were significant kinematic differences between the fastball and curveball but few kinetic differences. The change-up had lower joint kinetics, lower angular velocities, and different body positions than the other 3 pitch types had. Results for the slider were inconclusive because of small sample size.
Because the resultant joint loads were similar between the fastball and curveball, this study did not indicate that either pitch was more stressful or potentially dangerous for a collegiate pitcher. The low kinetics in the change-up implies that it is the safest.
关于变速球是否比快速球更具压力存在争议。以往的生物力学研究比较了运动学但未比较动力学。
快速球、曲线球、变速球和滑球之间的肘部和肩部力及扭矩在统计学上存在差异。
描述性实验室研究。
使用高速自动数字化系统对21名健康的大学投手进行研究。所有受试者都投快速球（n = 21），大多数投曲线球（n = 20）和变速球（n = 19），少数投滑球（n = 6）。使用逆动力学计算手腕、肘部和肩部的动力学。使用重复测量方差分析比较不同投球类型之间的9个动力学参数和26个运动学参数。
在肩部，变速球的内旋扭矩、水平内收扭矩、外展扭矩和近端力明显低于其他三种投球。快速球的肩部水平内收扭矩大于曲线球和滑球。滑球的肩部近端力大于曲线球。变速球的肘部近端力低于其他三种投球。快速球和曲线球的肘部内翻扭矩大于变速球。曲线球的肘部屈曲扭矩大于变速球。曲线球和变速球与快速球在运动学上存在差异，与以往研究一致。
快速球和曲线球之间存在显著的运动学差异，但动力学差异较小。变速球的关节动力学较低，角速度较低，身体姿势与其他三种投球类型不同。由于样本量小，滑球的结果尚无定论。
由于快速球和曲线球之间的合成关节负荷相似，本研究并未表明这两种投球对大学投手来说哪种更具压力或潜在危险。变速球的低动力学表明它是最安全的。
