Purpose: Previous investigations into concussions’ effects on Major League Baseball (MLB) players suggested that concussion negatively impacts traditional measures of batting performance. This study examined whether post-concussion batting performance, as measured by traditional, plate discipline, and batted ball statistics, in MLB players was worse than other post-injury performance.
Subjects and methods: MLB players with concussion from 2008 to 2014 were identified. Concussion was defined by placement on the disabled list or missing games due to concussion, post-concussive syndrome, or head trauma. Injuries causing players to be put on the disabled list were matched by age, position, and injury duration to serve as controls. Mixed effects models were used to estimate concussion’s influence after adjusting for potential confounders. The primary study outcome measurements were: traditional (eg, average), plate discipline (eg, swing-at-strike rate), and batted ball (eg, ground ball percentage) statistics.
Results: There were 85 concussed players and 212 controls included in the analyses. There was no significant difference in performance between concussed players and controls. However, concussed players started at a lower level of performance pre-event than the controls, striking out a 9.2% rate vs 8.2% (P=0.042) with an isolated power of 0.075 vs 0.082 (P=0.035). For concussed players, traditional batting statistics decreased before plate discipline metrics.
Conclusion: MLB players’ performance was lower after return from concussion, but no more than after return from other injuries. The decreased performance prior to concussion suggests that concussion-related performance declines may not be due exclusively to concussion and perhaps point to risk factors predisposing to concussion.

Keywords: MLB, head injury, professional sports, athletic performance, brain injury




中文翻译：

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脑震荡对美国职业棒球大联盟球员击球表现的影响

目的：先前对脑震荡对美国职棒大联盟（MLB）球员影响的调查表明，脑震荡会对传统的击球表现产生负面影响。这项研究检查了MLB运动员的传统击球，击打纪律和击球统计数据所得出的脑震荡击球后的表现是否比其他受伤后的表现差。
主题和方法：确定了2008年至2014年发生脑震荡的MLB球员。脑震荡的定义是放置在伤残者名单上或因脑震荡，脑震荡后综合症或头部外伤而缺席比赛。根据年龄，位置和伤害持续时间来匹配导致球员进入残疾名单的伤害，以作为控制对象。在对潜在的混杂因素进行调整之后，使用混合效应模型来估计脑震荡的影响。主要研究结果的度量标准是：传统（例如，平均值），板规（例如，挥杆挥杆率）和击球（例如，击球率）统计数据。
结果：分析中包括85位脑震荡的球员和212位控制者。脑震荡的球员和控制者之间的表现没有显着差异。但是，脑震荡的球员在赛前的表现要低于控制者，以9.2％的速度对比8.2％（P = 0.042），孤立的力量为0.075对0.082（P = 0.035）。对于脑震荡的球员，传统的击球统计在板规指标之前有所下降。
结论：从脑震荡回来后，美国职业棒球大联盟的球员的表现要低一些，但没有其他伤势回来后的表现多。脑震荡之前表现的下降表明脑震荡相关的表现下降可能并非完全是脑震荡引起的，而且可能指向易患脑震荡的危险因素。

关键词：美国职业棒球大联盟（MLB），头部受伤，职业体育，运动表现，脑损伤