The knee contains a number of cruciate ligaments including the medial, anterior and posterior. These bands of connective tissue are tasked in keeping the tibia from slipping forwards or backwards, and are crossed like the letter “X” to assure this happens. Unfortunately, like any part of the body, these ligaments are prone to injury; the anterior is the most commonly injured and the harder of the two to recover from. Severe injury to the Anterior Cruciate Ligament has slowly become an epidemic in the sporting world, particularly in the National Football League; the NFL has seen an increase in ACL injuries over recent years, and there are several possible causes to blame for the uptick: rule changes, preseason training, and genetics. 

One cause of increase in these injuries has become a popular scapegoat among players and fans, and it involves the rule changes enacted in 2013. Prior to the start of the 2013 preseason, amidst backlash of concussion concerns, the NFL instated new rules in an effort to limit the amount of hits that occur above the shoulders. This rule change included fines for malicious hits to the head, and made a player who performed one of these hits more likely to receive an in-game penalty. The changes were well received among most, but the start of preseason action brought concern over the ability of defensive players to adjust to a new hitting style. It turned out that the emphasis on not tackling a competitor high, directly led to a majority of tackles occurring below the belt line. Coincidentally, the 2013 preseason produced 15 ACL tears league wide, an all time high. The trend continued throughout the next five months of the season, and a record 63 ACL tears were documented. Even though this was an increase of 11.2% from the year prior, the media was slow to demand a change. The hypothesis was that players would eventually learn how to hit low and adjust to taking those hits; it seems they were right, as the total number of ACL tears decreased to 57 the following season, only one more than the 56 that occurred in 2012. The rule change was a tradeoff; it decreased the amount of concussions, but increased the frequency of on an injury more damaging to a career in an ACL tear.

Another possible cause for the increased frequency of ACL injuries might be the shortened mandatory team training sessions during the preseason.  During the 2011 preseason, a disagreement between the Collective Bargaining Agreement and the NFL led to a nearly a four month lockout. During the lockout players lost access to team training facilities, and most came back out of football shape. Among various new dealings, the settlement at the end of the lockout included a decrease in mandatory player involvement in offseason team training; this included Organized Team Activities (OTAs) and minicamps. Originally put in place to protect players, the settlement may be doing the exact opposite. Since 2011 there has been a spike in leg related injuries, including the ACL, MCL, and the Achilles Tendon. Many believe this is a result of lax player-to-team involvement, and the difference in what their body is capable of handling and what one’s body is asked to handle during the return to training. The relation between lack of training and ACL tears can be supported by the amount of non-contact knee injuries that occur during preseason; in their return to action, many players seem to tear their ACL on a cut that they made 1000 times without issue just a few months prior during the regular season. The issue has become so big between players and the media that the NFL is reviewing preseason policy and may make changes to the schedule.

The final and most probable cause of ACL injuries among NFL players involves something no one can control, genetics. A study done in 1992 to determine the cause of ACL injuries came back with overwhelming results. After studying over 1000 high school football players,  sport injury expert Dr. Tarek O. Souryal found that a vast majority of kids who have suffered torn ACLs have a smaller-than-average tunnel (foramen) in which the ligament is held. The tunnel is located at the end of the thigh bone, and a smaller than average hole restricts the amount of force the ACL can take during a cutting motion. In fact, in his research Dr. Souryal discovered that players with smaller than average tunnels were 26 times as likely to suffer injury. This is seemingly the answer to the ACL epidemic; as the game becomes faster and more physical, the amount of punishment an ACL in a smaller tunnel can take is put to the test. This may also lead to the percentage of ACLs that are re-injured after surgery.

The increase in the amount of ACL tears in the NFL can not be placed on the shoulders of any one possible cause. Instead, there are many factors that can lead to the tearing of one ACL, let alone more than 60. There are limited measures the NFL can take to reduce these numbers, but there are a few adjustments that can be made. Lessening the fines/penalties on above the shoulder hits, making players take very rigorous physicals before returning to preseason action, and giving proper rest to players after games can all work together to decrease the frequency of these injuries. A solution to preventing serious knee injuries is out there, and it’s only a matter of time before major sports leagues such as the NFL find it.

By Grant Hughes

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