Whelan Bridget M, Harmon Kimberly G, Aukerman Douglas F, Konstantinides Niki A, Poddar Sourav K, Bohr Adam D
Department of Family Medicine, University of Washington School of Medicine, Seattle, Washington, USA.
Sports Medicine, Samaritan Health Services, Corvallis, Oregon, USA.
Orthop J Sports Med. 2023 Aug 1;11(8):23259671231187893. doi: 10.1177/23259671231187893. eCollection 2023 Aug.
Kickoff plays in American football are associated with an increased risk of concussion compared with other play types. In 2018, the National Collegiate Athletic Association (NCAA) Football Rules Committee altered the kickoff rules so a fair catch inside the 25-yard line results in a touchback, with the ensuing drive starting on the 25-yard line. The intention was to decrease the number of kickoff returns with a corresponding decrease in the rate of concussions on kickoff plays.
To determine whether the 2018 rule changes had the intended effects in an NCAA Division 1 Conference.
Cohort study; Level of evidence, 3.
The study population included football athletes in the NCAA Pacific-12 (Pac-12) Conference. Data on the total number of plays, punts, kickoffs, touchbacks, and fair catches were obtained for all in-conference games from the 2016 to 2021 seasons. The number of game concussions and the play type were provided by each conference institution. Incidence of concussions occurring during kickoff plays before (2016-2017) and after (2018-2021) the rule change were compared with a difference-in-difference analysis using Poisson general linear models.
There were 242 concussions in 108,774 total plays in the study period, with an overall concussion rate of 2.2 per 1000 plays. The percentage of touchbacks increased significantly from 45% to 51% ( < .001) and the percentage of fair catches increased from 1% to 7% ( < .001) from before to after the rule change. Kickoffs accounted for 6% of plays both before and after the rule change and 11% of concussions before and 14% after the change. The mean annual concussion rate (per 1000 plays) on kickoffs was 3.42 before and 5.31 after the rule change (rate difference: 1.89; 95% confidence interval, -1.22 to 5.01).
Touchbacks and fair catches increased after the kickoff rule change, but there was not a corresponding decrease in concussions during kickoff plays as anticipated. Concussions occurring during other football plays remained stable.
与美式橄榄球的其他比赛类型相比，开球回攻时脑震荡风险增加。2018年，美国大学体育协会（NCAA）橄榄球规则委员会修改了开球规则，使得在25码线内的公平接球会导致球权转换，随后的进攻从25码线开始。目的是减少开球回攻次数，相应降低开球时的脑震荡发生率。
确定2018年的规则变更在NCAA一级联盟中是否产生了预期效果。
队列研究；证据等级，3级。
研究对象包括NCAA太平洋十二校联盟（Pac-12）的橄榄球运动员。获取了2016至2021赛季所有联盟内比赛的总比赛次数、弃踢、开球、球权转换和公平接球的数据。每个联盟机构提供了比赛脑震荡次数和比赛类型。使用泊松广义线性模型，通过差分分析比较规则变更前（2016 - 2017年）和变更后（2018 - 2021年）开球时发生脑震荡的发生率。
在研究期间的108,774次总比赛中发生了242次脑震荡，总体脑震荡发生率为每1000次比赛2.2次。规则变更前后，球权转换的百分比从45%显著增加到51%（P <.001），公平接球的百分比从1%增加到7%（P <.001）。开球在规则变更前后均占比赛次数的6%，变更前占脑震荡次数的11%，变更后占14%。开球时的年均脑震荡发生率（每1000次比赛）在规则变更前为3.42，变更后为5.31（发生率差异：1.89；95%置信区间，-1.22至5.0l）。
开球规则变更后，球权转换和公平接球次数增加，但开球时的脑震荡次数并未如预期那样相应减少。其他橄榄球比赛中的脑震荡次数保持稳定。
