Tocci Noah X, Howell David R, Sugimoto Dai, Dawkins Corey, Whited Amy, Bae Donald
1 The Micheli Center for Sports Injury Prevention.
2 Colby College.
J Appl Biomech. 2017 Oct 1;33(5):339-346. doi: 10.1123/jab.2016-0305. Epub 2017 Sep 23.
High elbow torque during a pitch may contribute to injury risk. Our objective was to determine the pitch mechanics associated with elbow varus torque in youth baseball pitchers. Eighteen male youth pitchers (age = 15.5 ± 1.6 years) threw 3 fastballs and 3 change-ups from a windup position while undergoing 3-dimensional kinematic analysis. Independent variables included ball release point distance, stride length, lateral pelvic tilt, and ball velocity. Two multiple regression models, separated by pitch type (fastball, change-up) were used to determine the association of independent variables with peak varus torque at the elbow. Fastball and change-up regression models indicated that stride length (β = 0.301, p = .015; β = 0.46, p < .001, respectively) and lateral pelvic tilt (β = -0.50, p < .001; β = -0.25, p = .04, respectively) were significantly associated with peak elbow varus torque. During fastballs, pitch velocity was significantly associated with peak elbow varus torque (β = 0.38, p = .002), while release point distance was significantly associated with peak elbow varus torque during change-ups (β = -0.33, p = .015). Youth pitchers with longer strides and less lateral pelvic tilt demonstrated greater elbow torque regardless of pitch type, while the association of ball velocity and release point to elbow varus torque was dependent on pitch type.
投球过程中肘部产生的高扭矩可能会增加受伤风险。我们的目的是确定青少年棒球投手与肘部内翻扭矩相关的投球力学机制。18名男性青少年投手（年龄=15.5±1.6岁）从准备姿势投出3个快球和3个变速球，同时进行三维运动学分析。自变量包括球的释放点距离、步幅、骨盆侧倾和球速。使用两个多元回归模型（按投球类型——快球、变速球区分）来确定自变量与肘部最大内翻扭矩之间的关联。快球和变速球的回归模型表明，步幅（β=0.301，p=0.015；β=0.46，p<0.001）和骨盆侧倾（β=-0.50，p<0.001；β=-0.25，p=0.04）分别与肘部最大内翻扭矩显著相关。在投快球时，投球速度与肘部最大内翻扭矩显著相关（β=0.38，p=0.002），而在投变速球时，释放点距离与肘部最大内翻扭矩显著相关（β=-0.33，p=0.015）。无论投球类型如何，步幅较长且骨盆侧倾较小的青少年投手肘部扭矩更大，而球速和释放点与肘部内翻扭矩的关联则取决于投球类型。
