Depatment of Mechanical Engineering and Engineering Science, University of North Carolina at Charlotte, Charlotte, NC, USA.
Tampa Bay Rays and University of South Florida, Tampa, FL, USA.
J Appl Biomech. 2024 Mar 11;40(3):209-216. doi: 10.1123/jab.2023-0205. Print 2024 Jun 1.
Altering baseball pitching mechanics affects both performance and the risk of injury. The purpose of this study is to investigate the relationships of shoulder external over internal rotation ratio (SEIR) and other shoulder rotational properties during physical exam and biomechanics of pitching for 177 collegiate baseball pitchers. The shoulder range of motion was quantitatively measured using a custom-made wireless device. Pitching motion data were collected at 240 Hz, and a custom program was created to calculate the throwing arm motion and loading during baseball pitching. Linear regression and analysis of variance tests were performed to investigate the relationships between the shoulder physical exam outcomes and throwing arm biomechanics. SEIR had significant correlations with shoulder horizontal adduction angle at foot contact, maximum shoulder external rotation angle, maximum shoulder linear velocity, and elbow angle at ball release. SEIR groups had significant differences in shoulder proximal force, adduction torque, internal rotation torque, and horizontal adduction torque, and in elbow medial force and varus torque. Glenohumeral internal rotation deficit and total rotational motion deficit had no relationships with throwing arm motions or joint loadings. Shoulder health should be monitored to improve understanding of pitching mechanics in collegiate baseball pitchers.
改变棒球投球动作会影响表现和受伤风险。本研究旨在调查 177 名大学生棒球投手中，体检时的肩部外旋/内旋比（SEIR）和其他肩部旋转特性，以及投球生物力学之间的关系。使用定制的无线设备对肩部活动范围进行定量测量。以 240Hz 的速度采集投球动作数据，并创建一个自定义程序来计算投球时的投掷臂运动和负荷。进行线性回归和方差分析测试，以研究肩部体检结果与投掷臂生物力学之间的关系。SEIR 与足接触时的肩部水平内收角、最大肩部外旋角度、最大肩部线性速度和投球时的肘部角度呈显著相关。SEIR 组在肩部近端力、内收扭矩、内旋扭矩和水平内收扭矩，以及肘部内侧力和外翻扭矩方面存在显著差异。盂肱关节内旋不足和总旋转运动不足与投掷臂运动或关节负荷没有关系。应监测肩部健康状况，以提高对大学生棒球投手投球力学的理解。
