Department of Orthopaedic Surgery, Columbia University Medical Center, New York, New York, USA. ; Department of Orthopaedic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Department of Orthopaedic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Orthop J Sports Med. 2014 Jun 9;2(6):2325967114537032. doi: 10.1177/2325967114537032. eCollection 2014 Jun.
Many factors are believed to contribute to throwing injuries in baseball pitchers, in particular overuse and poor throwing mechanics. The impact of fatigue on pitching biomechanics in live-game situations is not well understood.
Pitchers will demonstrate significant deviation in their pitching motions with increasing levels of fatigue.
Descriptive laboratory study.
Eleven National Collegiate Athletic Association (NCAA) Division I collegiate baseball pitchers were filmed in multiple live-game situations throughout a single season using 2 orthogonal high-speed cameras at 120 Hz. The first fastball of each inning and, when available, the fastball subsequent to the 15th and 30th pitch of each inning were recorded and analyzed for 26 kinematic parameters. Pitch count and velocity were recorded. Kinematic differences were assessed for association with pitch count and subjective fatigue measures over the course of each inning and game through the season.
Twenty-six games were recorded. Pitchers had a mean of 97.2 ± 16.1 pitches per start and 1079 ± 251 pitches per collegiate season. Increased hip lean at hand separation, elbow height at foot contact, and hip flexion and shoulder tilt at maximum external rotation were seen in innings lasting longer than 15 pitches. Maximum external rotation of the shoulder and elbow height at foot contact decreased over the course of a game. Hip lean at hand separation and elbow height at foot contact increased over the course of the season. Season pitch count was weakly correlated with increased shoulder external rotation and shoulder alignment at maximum external rotation and with shoulder abduction at ball release. Elbow flexion decreased with greater season pitch counts.
Hip lean, elbow height, and shoulder external rotation were the most sensitive kinematic parameters to inning, game, and season fatigue. Pitch count and fatigue have a significant impact on live-game pitching kinematics.
Fatigue likely alters pitching mechanics. Recognition of kinematic alterations may better demonstrate fatigue-related injury risk and may assist injury prevention in addition to standardized limitations of innings and pitches thrown.
许多因素被认为会导致棒球投手受伤，特别是过度使用和投球动作不佳。在实际比赛情况下，疲劳对投球生物力学的影响还不太清楚。
随着疲劳程度的增加，投手的投球动作会出现明显偏差。
描述性实验室研究。
在一个赛季中，使用 2 个正交高速摄像机以 120 Hz 的速度拍摄了 11 名美国大学生体育协会（NCAA）一级棒球投手的多个实际比赛情况。记录了每个局的第一记快球，以及在每个局的第 15 次和第 30 次投球后可用的快球，并对 26 个运动学参数进行了分析。记录了投球数和速度。通过整个赛季每个局和比赛的过程，评估运动学差异与投球数和主观疲劳测量的相关性。
记录了 26 场比赛。每位投手每场比赛的平均投球数为 97.2 ± 16.1 次，整个赛季的投球数为 1079 ± 251 次。在持续 15 次投球以上的局中，手分离时的髋部前倾、脚接触时的肘部高度、最大外旋时的髋部屈曲和肩部倾斜增加。在比赛过程中，肩部的最大外旋和脚接触时的肘部高度下降。手分离时的髋部前倾和脚接触时的肘部高度在整个赛季中增加。赛季投球数与增加的肩部外旋和最大外旋时的肩部对齐以及球释放时的肩部外展呈弱相关。随着赛季投球数的增加，肘部弯曲度减小。
髋部前倾、肘部高度和肩部外旋是对局、比赛和赛季疲劳最敏感的运动学参数。投球数和疲劳对实际比赛中的投球运动学有显著影响。
疲劳可能会改变投球动作。识别运动学变化可能更好地展示与疲劳相关的受伤风险，并除了规定的局数和投球数限制外，还可以帮助预防受伤。
