Center for Motion Analysis, Connecticut Children's Medical Center, Farmington, Connecticut, USA.
Am J Sports Med. 2019 Oct;47(12):2816-2820. doi: 10.1177/0363546519867934. Epub 2019 Aug 19.
The incidence of upper extremity injuries in baseball pitchers is increasing. Over the past decade, research has attempted to elucidate the cause of these injuries, focusing mainly on pitching arm mechanics with little examination of other important segments, such as the trunk. This is surprising, as trunk motion has been shown to have significant effects on pitching mechanics.
To determine the associations between trunk rotation, ball velocity, and the moments about the elbow joint.
Descriptive laboratory study.
Data collected using 3-dimensional motion analysis techniques from 99 collegiate pitchers (18.0-24.8 years) were analyzed. A random intercept mixed-effects regression model was used to determine if significant associations existed between trunk rotation and ball velocity or elbow varus moment.
Significant associations were found between trunk rotation angle at ball release and elbow varus moment ( = .019, β = 0.254) as well as ball velocity ( = .016, β = 0.060). For every 10° increase over the average trunk rotation angle at ball release, the elbow varus moment increased by 2.54 N·m and the ball velocity increased by 0.60 m/s. Additionally, the maximum rotational velocity of the trunk was positively associated with elbow varus moment ( < .001, β = 0.029) and ball velocity ( < .001, β = 0.007). For every 100 deg/s increase over the average maximum rotational velocity of the trunk, the elbow varus moment increased by 2.90 N·m and the ball velocity increased by 0.70 m/s.
In collegiate pitchers, trunk rotation angle at ball release was significantly associated with ball velocity and elbow varus moment. Also, an increase in maximum rotational velocity of the trunk was significantly associated with an increase in the ball velocity and elbow varus moment. This work demonstrates the importance of trunk mechanics in the kinetic chain of the pitch cycle.
Pitching coaches and trainers can use the results to stress the importance of trunk mechanics in pitching, specifically, combining adequate core function with increased trunk rotational velocity in an effort to increase pitching velocity without increasing elbow joint stress.
棒球投手中上肢受伤的发生率正在增加。在过去的十年中，研究人员试图阐明这些受伤的原因，主要集中在投球手臂的力学上，而很少检查躯干等其他重要部位。这令人惊讶，因为躯干运动已被证明对投球力学有重大影响。
确定躯干旋转、球速和肘关节力矩之间的关系。
描述性实验室研究。
使用三维运动分析技术从 99 名大学棒球投手（18.0-24.8 岁）中收集数据。使用随机截距混合效应回归模型来确定躯干旋转与球速或肘内翻力矩之间是否存在显著关联。
在球释放时的躯干旋转角度与肘内翻力矩（ =.019，β = 0.254）以及球速（ =.016，β = 0.060）之间发现了显著关联。在球释放时的躯干旋转角度每增加 10°，肘内翻力矩增加 2.54 N·m，球速增加 0.60 m/s。此外，躯干的最大旋转速度与肘内翻力矩（ <.001，β = 0.029）和球速（ <.001，β = 0.007）呈正相关。在躯干的最大旋转速度平均值每增加 100 deg/s 时，肘内翻力矩增加 2.90 N·m，球速增加 0.70 m/s。
在大学棒球投手中，球释放时的躯干旋转角度与球速和肘内翻力矩显著相关。此外，躯干最大旋转速度的增加与球速和肘内翻力矩的增加显著相关。这项工作表明了躯干力学在投球周期动力链中的重要性。
投球教练和训练师可以利用这些结果强调投球中躯干力学的重要性，特别是在不增加肘关节压力的情况下，将核心功能与增加的躯干旋转速度相结合，以提高投球速度。
