Background:Depending on anthropometrics and coaching style, pitchers are taught to pitch with a stride strategy that are traditionally classified as “tall and fall” or “drop and drive” for the purpose of maximizing pitch velocity.Purpose/Hypothesis:The purpose of this study was to determine the effects of stride strategy (tall and fall vs drop and drive) in college baseball pitching on pitch velocity and elbow valgus torque. It was hypothesized that pitch velocity and elbow valgus torque would increase as pitchers aligned more with the tall and fall technique.Study Design:Controlled laboratory study.Methods:Markerless motion capture data were recorded on 64 collegiate pitchers (height, 1.89 ± 0.06 m; weight, 93.06 ± 9.44 kg) during game play at the host institution during the 2023 season. Peak magnitudes of body center of mass (COM) vertical displacement were determined using a straight-line trajectory between peak knee height and lead foot contact and used as a continuous variable. Pitchers were required to throw ≥4 fastballs during their outing to be included in the analysis. Multilevel modeling was used to determine associations between peak magnitudes of positive and negative vertical displacement of COM on pitch velocity and elbow valgus torque. Every fastball throughout the season with biomechanics data for each pitcher was included in the multilevel model.Results:Fastball velocity was mean ± SD 90.68 ± 2.90 mph (40.54 ± 1.29 m/s). Mean maximal negative vertical COM displacement was −0.91 ± 0.47 inches (−0.023 ± 0.012 m), which occurred 18.1% ± 5.75% of the way between peak knee height and stride foot contact. Mean maximal positive vertical COM displacement was 1.73 ± 1.14 inches (0.044 ± 0.029 m), which occurred 65.7% ± 7.8% of the time from peak knee height to stride foot contact. Positive COM displacement (β = 0.54; P < .001) and timing of peak positive COM displacement (β = 1.82; P = .023) reduced interpitcher variance by 9.9% and improved the ability of our model to predict fastball velocity. Negative COM displacement improved the ability of our model to predict ball velocity (β = −0.45; P = .021). Vertical COM displacement did not influence elbow valgus torque.Conclusion:Increasing vertical COM displacement in either the positive or the negative direction resulted in increased fastball velocity but did not result in greater elbow valgus torque. This indicates that the stride method may be used for performance enhancement but is unlikely to influence ulnar collateral ligament injury risk in college baseball pitchers.Clinical Relevance:Clinicians should not use stride mechanics as an injury risk indicator or diagnostic factor in injury etiology for college baseball pitchers.

中文翻译：

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大学棒球投手中速度和肘外翻扭矩的 Tall and Fall vs Drop and Drive 策略


背景：根据人体测量学和教练风格，投手被教导以大步策略投球，传统上被归类为 “高而下 ”或 “下落和驱动 ”，以最大限度地提高投球速度。目的/假设： 本研究的目的是确定大学棒球投球中步幅策略 （高和跌倒与下降和驱动） 对投球速度和肘外翻扭矩的影响。据推测，投球速度和肘外翻扭矩会随着投手更多地适应高大和摔倒技术而增加。研究设计： 对照实验室研究。方法： 在 2023 赛季主办机构的比赛中，记录了 64 名大学投手 （身高 1.89 ± 0.06 m;体重 93.06 ± 9.44 kg） 的无标记动作捕捉数据。使用峰值膝关节高度和前足接触之间的直线轨迹确定体质心 （COM） 垂直位移的峰值幅度，并用作连续变量。投手需要在外出期间投出 ≥4 个快球才能被纳入分析。多级建模用于确定 COM 的正负垂直位移峰值幅度与俯仰速度和肘外翻扭矩之间的关联。整个赛季的每个快球以及每个投手的生物力学数据都包含在多级模型中。结果： 快球速度平均± SD 90.68 ± 2.90 mph （40.54 ± 1.29 m/s）。平均最大负垂直 COM 位移为 -0.91 ± 0.47 英寸（-0.023 ± 0.012 米），在峰值膝关节高度和步幅足接触之间发生 18.1% ± 5.75%。平均最大正垂直 COM 位移为 1.73 ± 1.14 英寸（0.044 ± 0.029 米），± 7 中发生了 65.7%。从膝盖峰值高度到跨步脚接触的时间为 8%。正 COM 位移 （β = 0.54;P < .001） 和峰值正 COM 位移的时间 （β = 1.82;P = .023） 将投手间方差降低了 9.9%，并提高了我们模型预测快球速度的能力。负 COM 位移提高了我们的模型预测球速的能力 （β = −0.45;P = .021）。垂直 COM 位移不会影响肘外翻扭矩。结论： 增加正或负方向的垂直 COM 位移导致快球速度增加，但不会导致更大的肘外翻扭矩。这表明步幅法可用于提高表现，但不太可能影响大学棒球投手尺侧副韧带损伤的风险。临床相关性： 临床医生不应将步幅力学用作大学棒球投手受伤病因的损伤风险指标或诊断因素。