Background:Softball pitchers frequently pitch at high volumes. Previous research has demonstrated changes in mechanics, range of motion, and perceived levels of fatigue and pain at high workloads. To date, little research has assessed changes in kinetics at high workloads across pitch types to understand the injury risk.Purpose:To examine changes in peak kinetics of the shoulder, elbow, and wrist of the pitching arm throughout a simulated game and doubleheader inning.Study Design:Descriptive laboratory study.Methods:A total of 19 high school softball pitchers (mean age, 15.1 ± 1.5 years; mean height, 1.6 ± 0.2 m; mean weight, 76.3 ± 16.9 kg) participated. Pitchers threw 4 innings of 25 randomly assigned pitches to mimic a game's high pitch count. Participants then rested for 30 minutes before subsequently proceeding to pitch the first inning of a doubleheader. Each pitcher threw a fastball, drop ball, curveball, and changeup. Peak shoulder, elbow, and wrist kinetics were compared across the first, last, and doubleheader innings and pitch types.Results:Compared with the first inning, significant decreases in kinetics were observed at the shoulder, elbow, and wrist in the last ( P < .016) and doubleheader ( P < .016) innings, particularly for shoulder and elbow compression force during the drop ball and curveball pitch types and wrist net force for all pitch types but the changeup. Significant decreases in elbow and wrist kinetics were observed during the changeup between the last and doubleheader innings ( P < .016). Furthermore, differences in kinetics were observed between pitch types ( P < .008); notably, the changeup had reduced kinetics compared with the fastball and breaking ball pitch types (drop ball, curveball) across innings.Conclusion:Across innings, attenuations in select joint kinetics of the pitching arm occurred that were specific to the pitch type. Across pitch types, peak kinetics was often greater during the fastball, while the changeup displayed the lowest peak kinetics.Clinical Relevance:The joints examined in this study are common sites of overuse injuries in pitchers. This work adds to previous findings on decrements in neuromuscular function as well as self-reported fatigue and pain with tournament-style pitching that may increase the injury risk. Collectively, these findings support developing a protocol combining functional testing and player-reported outcomes to aid sports specialists’ decisions for pitchers to continue to pitch or return to play, which may help prevent musculoskeletal injuries and time loss from sports participation.

中文翻译：

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模拟比赛和双赛局对不同投球类型垒球投球峰值动力学的影响


背景： 垒球投手经常以高音量投球。先前的研究表明，在高负荷下，力学、运动范围以及感知到的疲劳和疼痛水平会发生变化。迄今为止，很少有研究评估不同球场类型在高工作负载下的动力学变化以了解受伤风险。目的：检查在整个模拟比赛和双赛局中投球臂肩部、肘部和手腕的峰值动力学变化。研究设计： 描述性实验室研究。方法： 共有 19 名高中垒球投手 （平均年龄 15.1 ± 1.5 岁;平均身高 1.6 ± 0.2 m;平均体重 76.3 ± 16.9 kg）参加。投手投出 4 局 25 个随机分配的投球，以模拟比赛的高投球数。然后，参与者休息 30 分钟，然后继续进行双赛的第一局。每个投手都投出快球、落球、曲线球和换球。比较了第一局、最后一局和双赛局和投球类型的肩部、肘部和手腕峰值动力学。结果： 与第一局相比，在最后一局 （ P < .016） 和双赛 （ P < .016） 局中观察到肩部、肘部和手腕的动力学显着降低，特别是落球和曲线球投球类型期间的肩部和肘部压缩力以及除换球外所有投球类型的手腕净力。在最后一局和双赛局之间的转换过程中观察到肘部和手腕动力学的显着降低 （ P < .016）。此外，在间距类型之间观察到动力学差异 （ P < .008）;值得注意的是，与快球和突破球投球类型（落球、曲线球）相比，这种变化在各局中降低了动力学。结论： 跨局中，投球臂的特定关节动力学发生了特定于投球类型的衰减。在投球类型中，快球期间的峰值动力学通常更大，而变化显示最低的峰值动力学。临床相关性： 本研究中检查的关节是投手过度使用损伤的常见部位。这项工作增加了先前关于神经肌肉功能下降以及自我报告的锦标赛式投球疲劳和疼痛的发现，这可能会增加受伤风险。总的来说，这些发现支持制定一个结合功能测试和球员报告结果的方案，以帮助运动专家决定投手继续投球或重返比赛，这可能有助于防止肌肉骨骼损伤和参加运动的时间损失。