Anz Adam W, Bushnell Brandon D, Griffin Leah Passmore, Noonan Thomas J, Torry Michael R, Hawkins Richard J
Departments of Orthopedic Surgery, Wake Forest University, Winston-Salem, North Carolina, USA.
Am J Sports Med. 2010 Jul;38(7):1368-74. doi: 10.1177/0363546510363402. Epub 2010 Apr 16.
During the pitching motion, velocity is generated by the upper extremity kinetic chain on internal rotation of the shoulder and trunk translational/rotational motion. This generation of power places significant forces and torques on the elbow and shoulder. Elbow valgus torque and shoulder rotational torque are theoretically linked to elbow injury.
Pitchers experiencing higher levels of elbow valgus torque and shoulder external rotation torque throughout the pitching motion are more likely to suffer elbow injury than pitchers with lower levels of torque.
Cohort study; Level of evidence, 3.
With an established biomechanical analysis model, 23 professional baseball pitchers were videotaped during spring training games and followed prospectively for the next 3 seasons for elbow injury. A mixed statistical model using differences of least squares means and analysis of variance was used to analyze the association between elbow injury and torque levels throughout the pitching motion as well as at each major event within the pitching motion.
There were overall statistical trends relating elbow injury with both higher elbow valgus torque (P = .0547) and higher shoulder external rotation torque (P = .0548) throughout the entire pitching motion. More importantly, there was an individual significant correlation of elbow injury with both higher elbow valgus torque (P = .0130) and higher shoulder external rotation torque (P = .0018) at the late cocking phase (pitching event of maximum external rotation of the shoulder).
This study provides information that supports existing theories about how and why certain injuries occur during the throwing motion in baseball. The late cocking phase appears to be the critical point in the pitching motion, where higher levels of torque at the shoulder and elbow can result in increased risk of injury. Manipulation of pitching mechanics to alter these torque levels or using these measures to identify pitchers at risk may help decrease injury rates.
在投球动作过程中，速度是由上肢动力链在肩部内旋以及躯干平移/旋转运动时产生的。这种力量的产生会在肘部和肩部施加显著的力和扭矩。理论上，肘外翻扭矩和肩部旋转扭矩与肘部损伤相关。
在整个投球动作中经历较高水平肘外翻扭矩和肩部外旋扭矩的投手比扭矩水平较低的投手更易遭受肘部损伤。
队列研究；证据等级，3级。
利用已建立的生物力学分析模型，在春季训练赛期间对23名职业棒球投手进行录像，并在接下来的3个赛季对其肘部损伤情况进行前瞻性跟踪。使用最小二乘均值差异和方差分析的混合统计模型来分析整个投球动作以及投球动作中每个主要事件时肘部损伤与扭矩水平之间的关联。
在整个投球动作中，肘部损伤与较高的肘外翻扭矩（P = 0.0547）和较高的肩部外旋扭矩（P = 0.0548）总体上存在统计学趋势。更重要的是，在投球动作的后期上举阶段（肩部最大外旋的投球事件），肘部损伤与较高的肘外翻扭矩（P = 0.0130）和较高的肩部外旋扭矩（P = 0.0018）均存在个体显著相关性。
本研究提供的信息支持了关于棒球投球动作中某些损伤如何以及为何发生的现有理论。投球动作的后期上举阶段似乎是关键节点，此时肩部和肘部的较高扭矩水平可能会增加受伤风险。通过调整投球力学来改变这些扭矩水平或利用这些指标识别有受伤风险的投手，可能有助于降低受伤率。
