Misconceptions in NFL Injuries: A Study on the Achilles

Category: Sports, Trauma, Ankle, Achilles Introduction/Purpose: Injuries are an ever-present entity in the National Football League, with recent research highlighting American football with the highest injury incidence among all major sports. A torn Achilles can sideline a player for six to twelve months and reduce their power rankings by over fifty percent. Within Achilles tears, there was a focus on comparing rookie rates to the rest of the players, examining tear rates for different game conditions and studying the day of the week the injury occurred. Due to the impact of the injury and limited research, we sought to examine Achilles tears in the NFL from 2009-2016 to identify trends correlating tears with game and player demographics. Methods: NFL players with a diagnosed Achilles tear between 2009 and 2016 were selected as the study population for this retrospective analysis. Data on NFL injury was collected from an established database, previously comprised of publicly available athlete information. NFL player profiles were then employed to determine position, team and game statistics at time of injury. Injury rates were calculated as a percentage of total league games on Thursdays and Sundays. The proportion of rookies in the NFL was approximated by summing the number of draft picks and the number of signed, undrafted free agents and measured against the total number of roster spots before the commencement of the season. Game surface was discerned at time of injury by consulting a timeline of the field surfaces and cross referencing the date of the game. Game conditions, such as weather and temperature, were discerned from the game logs published on the NFL website. Results: There were 101 documented Achilles tears. Sixty-four percent (65/101) occurred before the official season, in training or pre-season games. Only 1% (1/101) of tears occurring during post-season play-offs. Twenty-nine percent (19/65) of the pre- season tears occurred in rookies and 97% (35/36) of the in-season game tears affected non-rookies. Thirty-six percent (36/101) of all documented tears occurred in undrafted free agents. Of players with Achilles tear, 58.41% (59/101) returned to play in the NFL after injury. Despite an average age of 26.7 years, the tear distribution was bimodal with players, ages 24 and 36, exhibited the highest rates of tear. With regard to tears during games, 43.18% occurred on grass and 56.82% occurred on turf. These values mirror their field representation in games. The average game temperature was 67.04 degrees Fahrenheit with wide stratification (range: 1-91 degrees). When examining rate of tears for players during away versus home games, there was not a significant difference of note; of the 45 in-game tears, 21 (46.67%) occurred in home games and 24 (53.33%) during away games. Conclusion: In our focused analysis of the Achilles in NFL athletes, we show no significant difference in tear rates when comparing grass and artificial turf surfaces and in comparing Thursday and Sunday games. When reviewing experience level, a large percent of the tears occurred in rookie players, especially during the pre-season, despite these players making up less than a quarter of the athletes. We also show that tears were not restricted to certain weather conditions. When analyzing career length post tear, most players that returned to play continued to perform at a high level. This challenges the perception of AT tear as a career-ending injury.