American Sports Medicine Institute, Birmingham, Alabama, USA.
Middlebury College, Middlebury, Vermont, USA.
Am J Sports Med. 2024 Jun;52(7):1671-1675. doi: 10.1177/03635465241247543. Epub 2024 Apr 30.
Historically, it was assumed by some that high leg lift with windup pitching generated more ball velocity whereas pitching from the stretch was quicker to reduce the risk of base stealing but also more stressful on the arm. However, many now believe that velocity and stress do not differ between windup and stretch and always pitching from the stretch is simpler than mastering 2 techniques.
PURPOSE/HYPOTHESIS: The purpose of this study was to compare windup and stretch fastball pitching biomechanics. It was hypothesized that there would be statistically significant and clinically important differences in ball velocity, timing of angular velocities, joint kinetics, and pitching kinematics.
Controlled laboratory study.
Fastball pitching biomechanics previously captured for 221 healthy baseball pitchers (105 professional, 52 collegiate, and 64 high school level) were analyzed. For each pitcher, data for 3 to 10 windup trials and 3 to 10 stretch trials were available. Ball velocity was recorded using a radar gun. A 12-camera, 240-Hz automated motion capture system was used to track 39 reflective markers attached to the pitcher. A total of 24 kinematic parameters, 4 temporal parameters, and 5 kinetic parameters were calculated. Data for each parameter were compared across the 2 techniques and 3 competition levels using 2-way repeated-measures analysis of variance ( < .01). Based on previous studies and the expertise of the investigators, the minimal clinically important difference (MCID) was set as 2° for angle measurements, 20 deg/s for angular velocities, 0.5 m/s for fastball velocity, and 0.3% body height × weight for normalized joint torque.
Fastball velocity was statistically greater from the windup than stretch for the collegiate subgroup but not for the other 2 levels. The collegiate level difference was below the MCID. Pitching from the windup generated greater front knee height and required more time from initiation of leg lift to front foot contact. From foot contact to ball release, there were 11 additional small, statistically significant differences between windup and stretch; however, each of these was well below the MCID.
Pitching from the stretch was quicker and should be used with runners on base to prevent stealing. Pitching from the windup and stretch produced similar ball velocity, joint kinetics, and kinematics. Thus, pitchers may choose to use both techniques or stretch only based on comfort and personal preference.
The decision to pitch from both the windup and stretch or only from the stretch should not affect a pitcher's performance or joint stress (and injury risk).
历史上，有些人认为高抬腿加侧身投球可以产生更高的球速，而伸卡投球则更快，可以减少偷垒的风险，但对手臂的压力也更大。然而，现在许多人认为，侧身投球和伸卡投球的速度和压力并没有区别，而且总是采用伸卡投球比掌握两种技术都要简单。
目的/假设：本研究的目的是比较侧身投球和伸卡投球的生物力学。假设在球速、角速度的时间、关节动力学和投球运动学方面会存在统计学上显著和临床上重要的差异。
对照实验室研究。
对 221 名健康棒球投手（105 名职业投手、52 名大学生投手和 64 名高中生投手）的侧身投球生物力学进行了分析。对于每个投手，都有 3 到 10 次侧身投球和 3 到 10 次伸卡投球的数据。球速使用雷达枪记录。使用 12 个摄像头、240Hz 自动运动捕捉系统跟踪附着在投手身上的 39 个反光标记。共计算了 24 个运动学参数、4 个时间参数和 5 个动力学参数。使用双向重复测量方差分析（<0.01）比较了这两种技术和 3 个竞争水平之间的每个参数。基于以往的研究和研究人员的专业知识，将最小临床重要差异（MCID）设定为角度测量 2°、角速度 20°/s、球速 0.5m/s 和归一化关节扭矩 0.3%身高×体重。
大学生组侧身投球的球速明显高于伸卡投球，但其他两个水平没有统计学差异。大学生组的差异低于 MCID。从侧身投球比伸卡投球需要更高的前膝高度，并且从抬腿开始到前脚接触需要更多的时间。从前脚接触到球出手，侧身投球和伸卡投球之间还有 11 个较小的、统计学上显著的差异；然而，每个差异都远低于 MCID。
伸卡投球更快，应该在有跑垒员时使用，以防止偷垒。侧身投球和伸卡投球产生的球速、关节动力学和运动学相似。因此，投手可以根据舒适度和个人喜好选择使用这两种技术或仅使用伸卡投球。
采用侧身投球和伸卡投球或仅采用伸卡投球的决定不应影响投手的表现或关节压力（和受伤风险）。
