Preseason elimination impact on anterior cruciate ligament injury in the national football league

BACKGROUND Anterior cruciate ligament(ACL)injuries represent detrimental injuries in the National Football League(NFL).A significant portion of these injuries often occur in preseason exhibitions.The Coronavirus disease 2019 pandemic presented a unique disruption to preseason NFL football with the cancelation of all preseason games.AIM To compare the incidence of ACL tears through the first eight weeks of the NFL season in 2020 to the mean incidence over the previous 5 seasons(2015-2019)and determine if there was any change in incidence with the elimination of the preseason.METHODS NFL players who suffered ACL tears during the preseason and first eight weeks of the NFL season from 2015-2020 were identified.The number of ACL injuries for the 2015-2019 seasons was compared to the 2020 season for four different timeframes.For each analysis,the cumulative number of ACL injuries to that time point was used to calculate the percent difference for descriptive analysis.Additionally,the number of teams with at least one player suffering an ACL tear were identified and compared using Chi-Squared testing.Finally,a cumulative relative risk was calculated for each week played.RESULTS There were 14 ACL tears through the first four games of the 2020 season,a 118.8%(14 vs 6.4)increase in comparison to the 5-year average over the first 4 regular season weeks of 2015-2019.However,when accounting for injuries occurring during the preseason from 2015-2019,there were 18.6%(14 vs 17.2)fewer total ACL injuries through regular season week 4 with no significant difference in percentage of teams impacted when these preseason injuries were accounted for P=0.394.Results were similar(19 vs 17.2)over 8 total games played(whether regular season or preseason),and over 8 regular season games(P=0.196,P=0.600).CONCLUSION The elimination of the NFL preseason resulted in a higher rate of injuries during the first 4 games of the regular season.However,these increases are offset by the injuries typically sustained during the preseason.This suggests there may be front-loading of injuries over the course of an NFL season,such that players may be more prone to injury when the intensity of play suddenly increases,whether in the preseason or regular season.

Citizenship, the Nation and the Race： China and the International Opium System, 1912-1931

This article analyzes China＇s attempts to participate in and use the negotiations about reforming the international opium control system in the interwar period. China had a contentious relationship with the international opium control system from its creation in the International Opium Convention of 1912 through the League of Nations opium control system of the 1920s and 1930s. The Chinese government wanted to gain acceptance for China as a modern state no longer in need of tutelage from the international community. They also wanted to portray the Chinese people as a modern race as a way of undermining colonial opium monopolies, which made a disproportionate amount of their profits from sales to Overseas Chinese. While they were not fully successful in either of these efforts, China did manage to win some support, drawing the United States into closer agreement with China＇s positions. Engagement with the international system also had a considerable impact on China＇s domestic opium politics and its broader diplomatic relationship with the major powers.