What is an ACL tear, and do the NFL have a hidden problem?

This week saw a number of NFL teams return for OTA’s. Organised Team Activities allow players to get back to a training regime within the facility of their respective team. The players don’t kit up and they don’t run contact drills, however, this hasn’t stopped injuries happening.

If you are an avid NFL fan, you will have heard the term “ACL Tear” many times during the off-season and regular season. Last year alone we saw three key players go out at some point during the season with this injury. New England Patriots wide receiver, Julian Edelman went out in pre-season against the Lions, reason given, “Torn ACL”, Deshaun Watson, November 2nd during practice, “Torn ACL” and Carson Wentz, December 10th against the Rams, “Torn ACL”.

But, what is an ACL?

ACL stands for Anterior Cruciate Ligament and is one of a pair of cruciate ligaments, with the other being the Posterior Cruciate Ligament. The ACL originates from deep within the notch of the distal femur, which in humans is the lower part of the thigh bone. The ACL attaches in front of the intercondyloid eminence of the Tibia where it blends with the anterior horn of the lateral meniscus.

Make sense? No, good me neither. So, lets reword that in a way that is easier to understand for those of us that are not doctors.

The ACL is an important structure that is found deep within the knee joint. Its job is to connect two bones, the thigh bone (femur) and the shin bone (tibia). The ACL is made predominantly of type 1 collagen which is found in soft tissue and bones throughout the body. The ACL looks small and unassuming, but can withstand forces of up to 500lbs.

The ACL’s main function is to provide the knee with stability and it does this in two ways.

1. Helps keep the tibia from moving too far forward on the femur

2. Keeps the knee stable during rotation

There are two distinct bundles that make up the ACL.

1. Antero Medial

2. Posterolateral

These two bundles help provide stability to the knee for complete range of motion. The Posterolateral is more proactive when the knee is extending and the Antero Medial is tighter when the knee flexes.

How big of a problem is this for the NFL?

The reason ACL injuries are so prevalent in the NFL is because of the nature of the sport and the athleticism required to play it. There is a lot of cutting and pivoting which puts more pressure on the knees and means they have an unusual burden of stress placed upon them. Here is a breakdown of the number of occurrences of ACL tears from 2012-2017 within the National Football League:

Findings

The latest study on ACL tears (via video analysis) was conducted looking at years 2013-2016. Throughout that period of time, there were 156 ACL injuries recorded with 77 of those occurring during the regular season and playoffs which means 79 of all ACL injuries for a period of 3 seasons were sustained during training camps and preseason games, which equates to 26 per season. One would think playing a game such as American Football that the majority of injuries would stem from contact made during plays, however, the results showed that 72.5% of all ACL injuries were sustained via a noncontact mechanism. There was a slight exception to this rule, offensive lineman sustained 80% of their ACL injuries via contact.

So let’s look at the noncontact ACL injuries and how they were sustained. The most common football activity at the time of injury was pivoting/cutting and the most common positions included hip abduction/flexion, early knee flexion/abduction and foot abduction/external rotation. Out of the injuries examined, there was no link between injury and playing surface.

Which positions are most effected?

To find our answer to this question, we must delve into a similar study as above from 2010-2013. This study examined 219 ACL tears that all took place in the NFL between the aforementioned years. This study found that receivers, made up of wide receivers and tight ends and backs, made up of linebackers, fullbacks and halfbacks were at a much greater risk of injury. The players with the lowest risk of injury were perimeter linemen, made up of defensive ends and offensive tackles. Interior linemen, made up of offensive guards, centers and defensive tackles had significantly higher injury risk compared to that of the aforementioned perimeter linemen.

These results also show that a large number of ACL injuries were sustained during preseason practices and games. August was the worst month in respect of injuries sustained.

Table below shows the monthly split, seasons 2010-2013:

Can anything be done to stop or limit the number of ACL injuries?

There have been many discussions over the course of the years on how to limit these kinds of injuries. Some have suggested ACL prevention programs which largely consist of jump and landing training. These were implemented for a very short period, however proved ineffective in the NFL. One of the main reasons for this was that during the course of the players regular training they were already training in that manor.

If you have ever watched an NCAA college game, you will see that offensive linemen and defensive linemen all wear knee braces. The reason for this is due partly because of ACL injuries. The NCAA mandated that this be so, hence why all linemen in college wear them. However, this isn’t the case in the NFL and many linemen don’t like the restrictive feeling it gives them. They value agility and performance.

The simple fact of the matter is whilst these braces do help in some instances, they certainly don’t protect against all ACL tears.

One theory is that players are bigger, faster and stronger. And whilst this is true to an extent, due to better fitness regimes, the need for bigger and stronger players throughout the league has inevitably played a part.

One major consideration in the modern-day NFL is the surface that the game is played on. During the years of Astroturf, ligament tears were notorious in the league. The league now uses what they call, sport-grass, however it’s still not real grass, and that ultimately plays apart.

Sadly, to conclude, there is no fix. NFL players are bigger, they move quicker therefore injuries such as ACL tears will become more common.

#ACL #FITNESS #NFL #NFLPlayers