Background: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.Study Design:Controlled laboratory study.Methods: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 ( P < .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.Results: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.Conclusion: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.Clinical Relevance: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).

中文翻译：

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棒球中缠绕和伸展投球生物力学的比较及其对安全和表现的影响

背景：从历史上看，一些人认为高抬腿投球会产生更高的球速，而伸展投球速度更快，可以减少盗垒的风险，但对手臂的压力也更大。然而，许多人现在认为，卷绕和伸展之间的速度和压力没有差异，并且总是从伸展投球比掌握两种技术更简单。目的/假设：本研究的目的是比较卷绕和伸展快球投球生物力学。假设球速度、角速度计时、关节动力学和投球运动学方面存在统计显着性和临床上重要的差异。研究设计：受控实验室研究。方法：之前针对 221 名健康棒球投手（105专业、52 所大学、64 所高中）进行了分析。对于每个投手，可以获得 3 至 10 次收紧试验和 3 至 10 次伸展试验的数据。使用雷达枪记录球速度。使用 12 个摄像头、240 Hz 自动动作捕捉系统来跟踪附在投手上的 39 个反射标记。总共计算了 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 (P < .01) 比较 2 种技术和 3 个竞争级别的每个参数的数据。根据之前的研究和研究者的专业知识，角度测量的最小临床重要差异（MCID）设置为2°，角速度设置为20 deg/s，快球速度设置为0.5 m/s，身高的0.3% ×结果：在统计上，大学亚组的快球速度在结束时比伸展时要大，但其他两个级别则不然。大学水平差异低于 MCID。从发条开始的俯仰会产生更大的前膝高度，并且从开始抬腿到前脚接触需要更多的时间。从脚接触到球释放，缠绕和伸展之间还有 11 个额外的微小的、统计上显着的差异；然而，这些都远低于 MCID。 结论：从伸展区投球速度更快，应该与上垒的跑步者一起使用，以防止偷球。卷起和伸展的投球产生相似的球速度、关节动力学和运动学。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展运动。 临床相关性：从卷起和伸展运动中投球或仅从伸展运动中投球的决定不应影响投手的表现或关节压力（以及受伤风险） ）。