Sports Medicine and Movement Laboratory, School of Kinesiology, Auburn University, Auburn, Alabama, USA.
Department of Educational Foundations, Leadership, and Technology, Auburn University, Auburn, Alabama, USA.
Am J Sports Med. 2021 Mar;49(4):1065-1072. doi: 10.1177/0363546520988172. Epub 2021 Feb 19.
A majority of softball literature focuses on the mechanics associated with pain and injury within a single pitch type per study; however, the generalizability of these findings is unknown since a kinematic comparison has yet to be performed between pitch types. Understanding kinematic differences between pitch types can be used to identify risk factors for injury, improve safety guidelines, and improve performance by linking specific mechanics with desired pitch outcomes.
HYPOTHESIS/PURPOSE: The purpose of this study was to compare kinematics between the fastball, changeup, curveball, and dropball pitch types in collegiate softball pitchers. It was hypothesized that there would be significant kinematic differences between pitch types.
Descriptive laboratory study.
A total of 28 female collegiate softball pitchers pitched 3 trials of each pitch type to a catcher at regulation distance. Pitch speed, stride length, trunk extension, trunk rotation, trunk lateral flexion, elbow flexion, and center of mass for each trial were calculated using an electromagnetic motion capture system and were averaged for analysis. A 1-way analysis of variance (ANOVA) was used to investigate pitch speed differences between the 4 pitch types. A 4 (pitch type) × 5 (event) within-athlete multivariate ANOVA was also used to determine kinematic differences.
The results revealed a significant difference in pitch speed between pitch types; a pitch type main effect for trunk extension, trunk rotation, trunk lateral flexion, and center of mass; and an event main effect for all variables except stride length. The results also revealed a pitch type by event interaction for trunk flexion, trunk lateral flexion, and center of mass. Specifically, the dropball type had less trunk extension than the fastball at all pitching events. Similarly, the curveball type had a more posteriorly shifted center of mass than the dropball at the last 3 pitching events of foot contact, ball release and follow-through.
Significant kinematic differences exist between pitch types, but these differences may be necessary to execute desired pitch outcomes.
This is the first study to analyze kinematic differences between pitch types in softball pitchers. Understanding the effects of different pitch types on kinematic parameters may enhance injury prevention and performance strategies for softball pitchers.
大多数垒球文献都集中在单一投球类型与疼痛和损伤相关的力学上；然而，由于尚未对投球类型之间进行运动学比较，这些发现的普遍性尚不清楚。了解投球类型之间的运动学差异可以用于确定损伤的危险因素，改进安全指南，并通过将特定力学与所需投球结果联系起来来提高性能。
假设/目的：本研究的目的是比较大学垒球投手之间的快球、变速球、曲线球和下坠球的运动学。假设投球类型之间会有显著的运动学差异。
描述性实验室研究。
共有 28 名女性大学垒球投手向距离规定的捕手投出 3 次每种投球类型的球。使用电磁运动捕捉系统计算每个试验的投球速度、步幅长度、躯干伸展、躯干旋转、躯干侧屈、肘部弯曲和质心，并进行平均分析。使用单向方差分析（ANOVA）来研究 4 种投球类型之间的投球速度差异。还使用 4（投球类型）×5（事件）运动员内多变量方差分析来确定运动学差异。
结果显示，投球类型之间的投球速度存在显著差异；躯干伸展、躯干旋转、躯干侧屈和质心存在投球类型主效应；除步幅长度外，所有变量都存在事件主效应。结果还显示了躯干弯曲、躯干侧屈和质心的投球类型与事件的相互作用。具体来说，在所有投球事件中，下坠球的躯干伸展都比快球小。同样，在脚接触、球释放和随球动作的最后 3 个投球事件中，曲线球的质心比下坠球更向后移。
投球类型之间存在显著的运动学差异，但这些差异可能是执行所需投球结果所必需的。
这是第一项分析垒球投手之间投球类型运动学差异的研究。了解不同投球类型对运动学参数的影响可能会增强垒球投手的伤预防和表现策略。
