Research Position Paper- DoubleA

The NFL: Artificial vs. Natural Grass

From the grandstands, artificial turf fields look so good it’s hard to believe they could be hazardous. But down on the field, where the cleats meet the turf and the athletes twist against the surface to propel themselves or push back their opponents, looks are irrelevant. When their knees buckle and they’re down on the turf crying for the trainer, the last thing wounded athletes are thinking of is how green the field looks.

One of the leading questions critics and players of the NFL have is what to do about the significant amount of knee injuries endured during an NFL season, and the correlation the playing fields have on these knee injuries. With multiple knee injuries occurring to big name players every season the NFL has a problem on their hands.

Due to the increasing number of concussions players were suffering over the past couple decades the NFL has tried to make the game safer. With new safety rules the NFL has managed to decrease the amount of head to head contact during games, but by doing this has raised the amount of low tackles which causes low blow tackles to the players knees.

Paired with concussions knee injuries are one of the biggest problems the NFL officials face now a days. Every season some team is affected by injuries along the way, but knee injuries are the biggest blow because they can take anywhere from 6-12 months to heal with rehab. This past season big names like Deshaun Watson, Carson Wentz, JJ Watt, Jason Peters all had big knee injuries that affected their team tremendously

Turf fields do have a direct impact on the increase in injuries we see in the NFL. 13 out of 32 stadiums sport an artificial turf material and even with less than half the number of fields of grass there is still more injuries on turf. An article written about the statistics of injuries on turf and grass fields from all the games from 2000-2009 found that there is a 22% increase in knee sprains on turf and a 67% increase in number of ACL sprains.

With this being said what exactly is the material the players are playing on? Field turf was a huge hit in the late 90s and most teams sport it now a days on their fields. The catch is though that the traction is so good with the new technology cleats that it is even easier to get a cleat stuck in the turf when planting or cutting.

We saw a prime example of this in 2017 when Bears tight end Zach Miller went to just plant while running from a defender and his knee bent the completely wrong when his knee just got caught up in the turf. It sparked a huge debate about the traction that turf causes while playing because Miller almost lost his leg due to the injury.

A study done in the late 90s tested a number of cleats from manufacturers and found that most cleats cause a safety implication because of how good the cleats react with the turf. The study suggested that people where turf cleats but as we all know no football players where them they all wear football cleats. Maybe the NFL can work on new cleat technology but for now safety precautions should be in effect after horrific injuries like Millers’.

Knee sprains are caused by unnatural movements during physical activity. Sudden turns or pivoting can cause injury to your ligaments. When these players get that much traction and that much body weight on a cut in the turf their body and knees cannot handle the pressure and force, so they give in on them. It’s a tragic thing to see. It is almost like you can’t watch a game without being scared every play someone can get hurt and their season can end on one play.

In 2010 a doctor by the name of Dr. Geier was asked a question on his blog about knee injuries. The question was “My question for you is do you think playing on turf field compared to regular grass has an impact on injuries?”

“Our varsity football team practices on grass field and play more than half of their games on turf. We had 3 meniscus injuries on the turf fields. Two were medial and one lateral; all 3 were repair. Also had a tibia/fibula fracture without impact. When asking the injured kids what they thought about the turf they all said it feels like their cleats stick into the ground.”

This question and evaluation was brought in by a random blogger named Gino who must play high school football.

The thing about Gino is the answer he received from the doctor was that it was the same results we talked about earlier 22% increase and 67% increase. He used the same study from earlier. Here is what he said,

“In a study performed by the National Football League Injury and Safety Panel, published in the October 2012 issue of the American Journal of Sports Medicine, Elliott B. Hershman et al., reviewed injury data from NFL games played between 2000 and 2009.They found that the injury rate of knee sprains as a whole was 22% higher on Field Turf than on natural grass. While MCL sprains did not occur at a rate significantly higher than on grass, rates of ACL sprains were 67% higher on Field Turf.”

There is obviously a clear correlation between turf and injuries. Yes, it was 3 kids in high school games but, my point is that in the article Dr. Geier flat-out gives us the results from a study done by the NFL and there were increases in knee sprains to the ACL and knee sprains altogether. This being said, knee sprains and other major knee injuries are overlooked in the NFL and some players may have to get surgery done multiple times throughout their careers due to sprains and tears.

I for one encountered my own injury on turf during a game where I played on turf. Of course, the one play I get put in at running back to run a jet sweep at the receiver position I tear my MCL. I just see it happening all over the place. Football is filled with injuries and at all levels but at the NFL level there is no doubt an increase of knee injuries on turf because of the size and speed of the players their bodies cannot keep up with the field conditions and wear and tear.

There is an article written about the cause factors of these freak knee injuries. The article states,

“Independent variables such as weather conditions, contact versus noncontact sport, shoe design, and field wear complicate many of the results reported in the literature, thereby preventing an accurate assessment of the true risk(s) associated with certain shoe-surface combinations. Historically, studies suggest that artificial turf is associated with a higher incidence of injury. Furthermore, reliable biomechanical data suggest that both the torque and strain experienced by lower extremity joints generated by artificial surfaces may be more than those generated by natural grass fields.”

As we see there is a lot of factors that it could come down to for cause of injuries but, with biomechanical data it says that it is caused by the torque and strain on joints. This is because the shoe surface is so good on turf that the stress endured by players knees is unbearable for the players knees. The article also claims that indeed there is a higher incidence of injury on artificial fields.

There can be tons of factors involved in why these freak knee injuries occur so often on artificial turf but, the only thing that we know is that artificial must go. If the injury rates keep coming back year after year the same, then something must be done. It’ll just be another one of Roger Goddell’s flaws in his term as commissioner. Player safety is huge in the NFL now a days with players retiring after a couple of seasons in their prime because they must look into the future and see if they can really go through with the injury worries anymore. Being an NFL athlete is hard and it takes a tole on your body but, when you are playing on these dangerous surfaces it can cut your career way short than expected. Something must be done now.

Critics of natural grass playing surfaces like to cite the woeful condition of their neighborhood high school field to illustrate the danger to athletes’ ankles and knees. Granted, those fields suffer a lot of abuse, and playing on them after several home games in a row is hazardous. It’s even true that many school districts have replaced their grass fields with artificial turf because they can’t afford the high cost of maintaining perfect grass. But the NFL, for the sake of reducing player injuries, is willing and able to make that continuing investment.

Fans of artificial turf say that grass requires too much maintenance. They contend that keeping fields polished and playable throughout the weather conditions and the strenuous foot traffic of an NFL season requires an expensive professional grounds crew. But the same objection is not made about baseball fields, which are always grass, nicely kept to avoid dangerous patches. To be fair, field turf has to be maintained too, and uneven wear creates dangerous worn down areas that should result in its replacement.

People may also say that grass can get real cold in areas like Minnesota and Green Bay. Yes, this is true, and it is almost like the players are playing on bricks but in Minnesota they just installed nice turf and first game of the year top pick Dalvin Cook tears his ACL cutting non-contact on the turf. Injuries like this are popping up everywhere.

In an article written about the Houston Texans, Texans cornerback D.J. Swearinger talked about the awful field conditions at NRG stadium. They have turf square panels that get put in for every game. They essentially have seams in them as would Astroturf and everyone knows how awful Astroturf was to play on. Swearinger says in the article, “We actually said that the day before (the injury). If somebody was running right here and (they) plant, their ACL or MCL is gone just because of how deep the holes are.” Swearinger is referring to an injury that happened to top pick Jadeveon Clowney. Clowney was running for a tackle and got his leg caught in a seam and twisted his knee the wrong way and tore his meniscus.

People may also say that grass can get real cold in areas like Minnesota and Green Bay. Yes, this is true, and it is almost like you are playing on bricks but in Minnesota they just installed nice turf and first game of the year top pick Dalvin Cook tears his ACL cutting non-contact on the turf. Injuries like this are popping up everywhere.

In an article written by, they bring up the amount of ACL injuries that occur on turf fields. The number was staggering high when they found the results. The author states,

“The panel started to notice a higher rate of injuries on the new turf in evaluating the data that the NFL compiles each season, Hershman said. Once enough games had been played on the newer surfaces to do a scientific analysis, the panel found that anterior cruciate ligament injuries and a more serious type of ankle sprain occurred at a higher rate that is statistically significant.”

This panel was doing research from every game from the 2002-2008 season and how many ACL injuries occurred during these seasons. Their results were clear-cut and they came up with one result. That artificial turf causes more lower extremity injuries than natural grass fields. Their number is so staggering that they say that there is an 88% percent chance that you obtain a knee injury on artificial turf than natural grass.

Opposers may say that these results were too old to our times it has been ten years since they have conducted research on these fields. They also could say times have changed and that player safety is more thought about today and that they would have increased the quality of the fields in order to keep more players healthy. This may be the case but, in an article written in 2018 has stated the same results still occur today. The article says,

A variety of design factors have been hypothesized to play a role, including surface hardness, rotational stiffness, and release torque. These physical characteristics may interact with other environmental factors such as cleat design, surface moisture levels, and ambient temperature. Partially in response to these concerns, manufacturers have continued to refine these products to bring their physical characteristics closer in line to natural grass surfaces, but concerns among players, medical personnel, and the public persist.

The article furthers my point that artificial turf fields are still causing these injury bug problems to players now a days. Like the article says with all these risk factors it just makes the fields way more dangerous than the NFL wants them. It’s almost nerve-racking to watch your team play a game because you’re scared that your best players could go down in any play of any game because injuries are that common in the NFL. The biggest factor I see there in the article is rotational stiffness and release torque. I have seen these types of factors come up everywhere in other articles. The feel for turf is so good that people cannot cut on these fields properly and their knees bend the wrong ways and so much stress is being put on these ligaments they eventually just give out. With football players are the biggest and the strongest overall out of most sports so when you add these guys to these sketchy and unqualified fields long-term and career ending injuries could occur and that is the last thing the NFL wants.

There is no reason why teams can’t sport some nice Bermuda grass in a dome stadium. It doesn’t make teams cooler to have turf in their billion-dollar dome, what matters is player safety. Players all over the league past and present have questioned player safety with concussions. Knee injuries are the second most occurring injury in the NFL and they require surgery and months of rehab, the time to speak up is now.

To conclude, I think it is conclusive that there needs to be a change in the way turf fields in the NFL are kept and I think as this last season in the NFL teams got slapped in the face with the injury bug. I think that the NFL and team owners will discuss or should discuss ways on how to make the game safer for all players. Just like the concussion issues the NFL had endured I think it has to take a look at the knee injury numbers and truly come up with a conclusion as to how this is happening. To my estimation I truly believe that the turf fields are not helping this problem and I believe there might be a solution. Either teams convert to a universal playing field surface so teams are used to the surface or the NFL takes a look at the science between the traction of cleats and the turf to find a solution as to safer kinds of cleats that the players can play on and enjoy wearing.


NFL panel finds some knee, ankle injuries more common on turf. (n.d.). Retrieved from

NRG Stadium’s Playing Surface An ‘Abomination’. (2014, September 09). Retrieved from

6 – Risk of Anterior Cruciate Ligament Injury as a Function of Type of Playing Surface. (n.d.). Retrieved from

Is an ACL tear more common on artificial turf or grass? (2018, March 03). Retrieved from

A Review of Synthetic Playing Surfaces, the Shoe-Surface Interface, and Lower Extremity Injuries in Athletes. (n.d.). Retrieved from

Hershman, E. B., Anderson, R., Bergfeld, J. A., Bradley, J. P., Coughlin, M. J., Johnson, R. J., . . . Tucker, A. (2012, 09). An Analysis of Specific Lower Extremity Injury Rates on Grass and FieldTurf Playing Surfaces in National Football League Games. The American Journal of Sports Medicine, 40(10), 2200-2205. doi:10.1177/0363546512458888


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: