Department of Orthopedics and Rehabilitation, Division of Sports Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Am J Sports Med. 2019 Aug;47(10):2294-2299. doi: 10.1177/0363546519860120. Epub 2019 Jul 15.
Sport-related concussion (SRC) has been associated with cognitive impairment, depression, and chronic traumatic encephalopathy. American football is the most popular sport among males in the United States and has one of the highest concussion rates among high school sports. Measured head impacts and concussions are approximately 4 times more common in contact practices compared with noncontact practices. The Wisconsin Interscholastic Athletic Association passed new rules defining and limiting contact during practice before the 2014 football season.
To determine if the SRC rate is lower after a rule change that limited the amount and duration of full-contact activities during high school football practice sessions.
Cohort study; Level of evidence, 2.
A total of 2081 high school football athletes enrolled and participated in the study in 2012-2013 (before the rule change), and 945 players participated in the study in 2014 (after the rule change). Players self-reported previous concussion and demographic information. Athletic trainers recorded athlete exposures (AEs), concussion incidence, and days lost for each SRC. Chi-square tests were used to compare the incidence of SRC in prerule 2012-2013 seasons with the incidence in the postrule 2014 season. Wilcoxon rank sum tests were used to determine differences in days lost because of SRC.
A total of 67 players (7.1%) sustained 70 SRCs in 2014. The overall rate of SRC per 1000 AEs was 1.28 in 2014 as compared with 1.58 in 2012-2013 ( = .139). The rate of SRC sustained overall in practice was significantly lower ( = .003) after the rule change in 2014 (15 SRCs, 0.33 per 1000 AEs) as compared with prerule 2012-2013 (86 SRCs, 0.76 per 1000 AEs). There was no difference ( = .999) in the rate of SRC sustained in games before (5.81 per 1000 AEs) and after (5.74 per 1000 AEs) the rule change. There was no difference ( = .967) in days lost from SRC before (13 days lost [interquartile range, 10-18]) and after (14 days lost [interquartile range, 10-16]) the rule change.
The rate of SRC sustained in high school football practice decreased by 57% after a rule change limiting the amount and duration of full-contact activities, with no change in competition concussion rate. Limitations on contact during high school football practice may be one effective measure to reduce the incidence of SRC.
运动相关性脑震荡（SRC）与认知障碍、抑郁和慢性创伤性脑病有关。美式足球是美国男性最受欢迎的运动，也是高中运动中脑震荡发生率最高的运动之一。与非接触练习相比，接触练习中测量的头部撞击和脑震荡大约高出 4 倍。威斯康星州校际体育协会在 2014 年橄榄球赛季前通过了新规则，规定并限制了练习中的接触。
确定在一项限制高中橄榄球练习中全接触活动的数量和持续时间的规则改变后，SRC 发生率是否降低。
队列研究；证据水平，2 级。
共有 2081 名高中橄榄球运动员在 2012-2013 年（规则改变前）和 945 名运动员在 2014 年（规则改变后）参加了这项研究。运动员自我报告了以前的脑震荡和人口统计学信息。运动训练员记录了运动员的暴露情况（AE）、脑震荡发生率和每个 SRC 的损失天数。使用卡方检验比较了规则改变前的 2012-2013 赛季和规则改变后的 2014 赛季 SRC 的发生率。使用 Wilcoxon 秩和检验确定了 SRC 损失天数的差异。
共有 67 名运动员（7.1%）在 2014 年遭受了 70 次 SRC。2014 年每 1000 次 AE 的 SRC 总发生率为 1.28，而 2012-2013 年为 1.58（ =.139）。与规则改变前的 2012-2013 年相比（86 次 SRC，每 1000 AE 为 0.76），规则改变后（15 次 SRC，每 1000 AE 为 0.33），练习中 SRC 的总发生率明显降低（ =.003）。在规则改变前后（每 1000 AE 分别为 5.81 和 5.74），比赛中 SRC 的发生率没有差异（ =.999）。在规则改变前后（分别为 13 天和 14 天[四分位距，10-18]），因 SRC 而损失的天数没有差异（ =.967）。
在限制高量和持续时间的全接触活动的规则改变后，高中橄榄球练习中 SRC 的发生率降低了 57%，而比赛中脑震荡的发生率没有变化。限制高中橄榄球练习中的接触可能是降低 SRC 发生率的有效措施之一。
