Writers of Pro Football Prospectus 2008

12 Mar 2010

Study Finds Injuries More Common on Field Turf

A new report says that certain injuries are more common on Field Turf than natural grass. In particular, from 2002-2008, ACL injuries were 88 percent more likely in games on Field Turf. Ankle sprains were 32 percent more likely. Does this create an incentive for teams to go back to grass?

Posted by: Aaron Schatz on 12 Mar 2010

43 comments, Last at 15 Mar 2010, 9:34pm by tuluse


by Noah Arkadia :: Fri, 03/12/2010 - 3:25pm

Is this a big surprise to anyone?

by Nathan :: Fri, 03/12/2010 - 4:28pm

That more people are injured on it, no. That 88% more people are injured on it, yes.

by Kevin from Philly :: Fri, 03/12/2010 - 3:29pm

Don't see how you'd ever be able to get rid of artificial turf, even if it isn't as safe as grass. Grass is too expensive to maintain for a lot of clubs and the fields always seem to turn into mud bogs by the end of the season - at least in the northern part of the country.

by Jmagik (not verified) :: Fri, 03/12/2010 - 3:43pm

"Too expensive to maintain"? Compared to what? Try comparing it to the cost of rehabbing a single ACL injury, replacing the player for the year, taking the salary hit, etc. Field Turf was a stupid investment from any number of perspectives, including a basic financial one.

by Kevin from Philly :: Mon, 03/15/2010 - 10:23am

If the likelihood of injury was ten times greater with turf, then yeah, it would obviously be a poor choice. When the injury rate is 70% greater, who's to say one particular injury was caused by the turf? The teams probably have computers full of actuarial charts that tell them what the added risk is for an artificial turf field. Compare the cost of maintaining grass - irrigation, periodic resodding, etc. vice a quick cleanup before the season (and not much else) for turf, and it's probably an easy business decision.

by tuluse :: Mon, 03/15/2010 - 9:34pm

I really doubt they do this.

by discostu :: Fri, 03/12/2010 - 5:46pm

TV revenue alone for the teams works out to well over $100 million a year. There's no such thing as "too expensive".

by Kevin from Philly :: Mon, 03/15/2010 - 10:28am

These are NFL owners we're talking about. The same guys that didn't want to buy expensive helmets to prevent concussions. You honestly think owners like the Glazers would spend more than they absolutely have to?

by loneweasel (not verified) :: Fri, 03/12/2010 - 3:47pm

Field Turf=more controlled environment=more scoring=higher ratings

Injury prevention was not and never has been a big concern.

by Bright Blue Shorts :: Fri, 03/12/2010 - 3:47pm

Although it doesn't analyse it beyond "making sure players are wearing the right shoes" ... the conventional wisdom about astroturf was that it caused injuries because cleats got stuck in it.

But I wonder if more injuries occur on FieldTurf because it's a quicker surface? If you're moving faster and try to turn or cut there's likely to be more force on your joints and ligaments.

by sundown (not verified) :: Fri, 03/12/2010 - 5:08pm

The "grippyness" is also a big issue. It doesn't give when you go to stop like grass--you stop dead in your tracks. And that puts lots of stress on everything.

by FooBarFooFoo (not verified) :: Fri, 03/12/2010 - 4:00pm

Ask Belichick about the grass field at Reliant Stadium.

He's probably going to call it "terrible"

by bengalmike (not verified) :: Sat, 03/13/2010 - 5:21am

I'm guessing he calls it "probable"

by Bobman :: Sun, 03/14/2010 - 10:40pm

Questionable: Chlorophyll

by Bill Barnwell :: Fri, 03/12/2010 - 4:15pm

In doing some research, I came across a 1993 Sports Illustrated story on AstroTurf that might be of some interest to our readers: http://sportsillustrated.cnn.com/vault/article/magazine/MAG1137928/1/ind...

by The Peepshow (not verified) :: Fri, 03/12/2010 - 5:06pm

I guarantee you that a punt will not land and stick into the ground on FieldTurf regardless of the weather…

by galactic_dev :: Sat, 03/13/2010 - 3:26am

Heheheh, that was awesome!

by DZ (not verified) :: Fri, 03/12/2010 - 5:13pm

5 of the 8 most injured teams (Detroit, Cincy, Indy, STL, Seattle) in football according to AGL over the past three seasons use field turf. There are only 8 teams total that use it.


by Lola was a dude (not verified) :: Fri, 03/12/2010 - 5:50pm

Could be interesting, or just a coincidence. Were the injuries the same kind of injuries that the article talks about?

FWIW, it wasn't that many years ago that people on this site used to mention Indy having abnormally GOOD luck with injuries, and that was when they had the supposedly horrible Astroturf. Maybe this stuff just goes in cycles.

by Lou :: Fri, 03/12/2010 - 5:42pm

so does this make the success of Dallas's training staff all the more impressive?

by Temo :: Sat, 03/13/2010 - 4:25pm

Dallas doesn't use FieldTurf, they use another brand of artificial turf from a company named Hellas Construction, called "RealGrass" (which isn't real grass, just an approximation).

I don't remember what they used in the old Cowboys Stadium, but I don't think that was FieldTurf either.

by Raiderjoe :: Sun, 03/14/2010 - 2:48pm

team used Sportifeld Realgrass in old stadium.

reemember it was 2002 season when swithc old style astrotruf to fieldturd during seaosn

pates in 2006 soeoans are other tam that change surface during seaosn

by tunesmith :: Fri, 03/12/2010 - 5:47pm

Maybe folks should train on field turf to strengthen ligaments and tendons, but then play all year on grass?

by SJT (not verified) :: Fri, 03/12/2010 - 9:42pm

Something not addressed here is how Field Turf compares to the old astroturf. Its it safer? Is it an improvement?

Also, we have to remember that not all injuries are turf related. For example, NE has Field Turf, and Tom Brady blew his knee out right in the middle of it. I think its safe to say that the turf itself had a lot less to do with it than the human missile which collided with his leg.

by Bobman :: Sun, 03/14/2010 - 10:46pm

Might be BETTER for some injuries, like concussions...? It's a pretty padded surface. In the Pacific NW where grass fields are mud-holes 8 months a year, my kids play baseball and football on field turf most of the time.

I don't know of a professional grounds crew that could keep Qwest Field natural grass and playable all season--it's the freakin climate--and a mud-slicked shithole is worse/more dangerous than Field Turf. I suspect that a rock-solid frozen field like I played on in my youth is also worse than Field Turf for injuries.

by Chris F (not verified) :: Fri, 03/12/2010 - 10:58pm

The problem is probably the rubber that they use as artificial dirt. It's got more give than the concrete under the astroturf, but it doesn't break away as well as real dirt/turf. Maybe something like cork would better.

When FIFA World Cup was in the US in the 90s, they put grass in the domes by breaking the field into pieces and wheeling it outside when the games weren't being played. The Cowboys basically do this with the entire field. With smaller pieces, you could keep "spares" to replace worn-out turf (and make a few bucks selling "game-played turf"?).

by jimmy oz (not verified) :: Sat, 03/13/2010 - 1:51am

?? Crazy. Euro soccer teams manage to replace their turf a couple of times a year if needed. I can't imagine it would be that hard to grow grass in winter in either the bottom right or left corners of the map

by Temo :: Sat, 03/13/2010 - 4:12pm

I've played extensively on fieldturf and always loved it, even preferred it to natural grass. I've never been faster or quicker on any other surface than I have been on Field Turf.

Maybe the performance is what's an issue though, maybe high performance athletes are going too fast on this surface.

by Bobman :: Mon, 03/15/2010 - 12:47am

I think that's the issue--the two studies referenced were NFL-only and HS/College only. The top athletes might generate too much speed, force, etc on it that our bodies are just not evolved to deal with.

But my experiences have all been favorable (aside from tracking the rubber pellets around everywhere). Granted 8 and 9 year-olds aren't overly demanding, and actually prefere a good loong slide in the mud every once in a while... just not when they're trying to turn the corner for a 60 yard run.

by boing3887 (not verified) :: Sat, 03/13/2010 - 5:22pm

anyone who's been paying attention knows the monster that field turf is. i don't know why those stupid nfl team executives or whatever chose to use field turf over regular grass. i have no idea what they were thinking - how would they know what surface is best for football when they don't even play?

i seriously think that nfl players should have more control over these kinds of issues

by Nathan :: Sat, 03/13/2010 - 6:24pm

also seems like a bad investment... save groundskeeping fees but expose all your multimillion dollar players to career threatening knee injuries? penny wise, pound foolish.

by towishimp (not verified) :: Sat, 03/13/2010 - 6:45pm

Well, before reading this article (and it holds true even after reading this), I'd read conflicting studies on the incidence of injuries on field turf vs. natural grass. I've read that there's little difference, that each is worse than the other, and that the number of injuries is close, but the types of injuries vary. I followed the issue in soccer, where the facts have been blurred by a at times irrational hatred of field turf.

I think the jury may still be out. It looks like well-maintained grass may be best, but is poorly maintained grass better than field turf, for example?

by justanothersteve :: Sun, 03/14/2010 - 10:50am

If the Packers at almost 45N can play on grass - and most players consider it one of the best field surfaces to play on - there's no reason for any team playing outdoors not to have a grass field. And I love what the Cards did; grow the grass outside then move the entire field inside for games.

by Jerry :: Mon, 03/15/2010 - 3:35am

Are there any non-Packer events at Lambeau? Have a soccer team, or even a college football team, as a co-tenant, and see how the grass does.

by Byrk (not verified) :: Sun, 03/14/2010 - 9:55pm

The Packers have quite a pretty good field, I know a lot of the details because I know the people involved in re-doing their field a few years ago. The Packers have had for some time a boiler system and coils underneath their field to prevent it from freezing in the winter. The crew also installed a mostly grass field, with a certain twist. Synthetic fibers every couple of cm were driven deep into the field to keep it from being a mud pit like it used to. Before the redesign the only reason the field looked green on game day was due to painting the field green.

However, I'll also question any study that only looks at two types of injuries, instead of injuries as a whole. It could be just a coincidence that one type of injury appears more prevalent than others and we're seeing a pattern where none exists. If you look at hundreds of injuries there's bound to be one or two, just by random chance that are more prevalent on one field than another. Even if the field is causing the injuries, it may prevent others making it wash between field types.

The reason why soccer games are played on natural grass is because the international rules state it has to be played on natural grass. Seattle lays sod down for official international games. This is because soccer is far more dependent on how a ball rolls on the grass, so they try to eliminate as many variables as possible. It isn't because they feel that it's more dangerous or anything like that.

by Bobman :: Mon, 03/15/2010 - 12:54am

That was fascinating about the GB field. As big a committment to grass (in terms of up front costs and efforts) as any turf field is.

Seattle (read: Paul Allen) was really torn about turf/grass because of soccer. The Sounders play on the field turf, IIRC. Out here, football is at the wrong time of year for grass. Even after a month of sunshine, my lawn sometimes squelches if you step in the wrong place in June. True, I maintain it my amateur-ass self and tend to over-water, but the fact remains that football season is the rainy season here and two weeks of rain, coupled with a hard fought game on Sunday = a mud pit that won't resemble a grass field for months. (There's a reason the Seahawks' new practrice facility is 90% indoors.) They could install patches of sod, but that leaves seams and probably more injury issues....

by Red5 (not verified) :: Sun, 03/14/2010 - 11:34pm

It would be interesting to read the actual article. I'd like to know what their p-values and confidence intervals are. Also of note, a 3 years study comparing fieldturf and natural grass showed that playing on fieldturf made one LESS likely to be injured and one for high school players was inconclusive. Me thinks we should continue to investigate. Course, I don't see anyway they're actually gonna get a randomized clinical trial done on this.

by bubqr :: Mon, 03/15/2010 - 5:36am

European soccer fields play up to 35 games per season at home on grass fields, in some cold weather areas, so how can it be that difficult to play 8 games in the same circumstances ?

by Neoplatonist Bolthead (not verified) :: Mon, 03/15/2010 - 8:49am

'Cause soccer players don't mix it up en masse. There's no way football isn't ten times harder on turf than soccer is. Those guys are running and kicking, not blocking and tackling.

by Kevin from Philly :: Mon, 03/15/2010 - 9:57am

Also, there aren't too many 350 pound soccer players.

by Theo :: Mon, 03/15/2010 - 11:06am

Because with soccer, there are not 5 300lb guys pushing around 4 other 300lb guys.

The worst thing soccer players do to a field is walk on it and fall on it when another players comes within a yard of them after which they roll around like they've been shot in the kneecap and then furiously ask for a yellow card.

by Chris UK :: Mon, 03/15/2010 - 12:45pm

A better comparison in terms of wear and tear would be European Rugby. Although thinking about it European rugby players aren't wearing pads/helmets etc. which must do the turf a lot of damage.

Some of the English Rugby clubs share with Soccer teams without disastrous results so it must surely be possible to manage 8-10 games outdoors.

by Kevin from Philly :: Mon, 03/15/2010 - 4:32pm

If all they were used for were 8-10 games, maybe so. You're forgetting all the concerts that are staged at many of these stadiums - plywood coverings and thousands of dancing fans do a number on grass. Also, most NFL teams have contracts with local college football teams to use the fields for Saturday games or pro soccer during the week. That's a lot of heavy usage, during a time of year where you get cold weather, rains (or droughts, depending on where you're at). Also, don't forget that you also have to keep the grass going during the summer, which in the Northeast can be very hot. Hell, I have a half acre lawn with relatively little activity, and it's a pain to keep in decent shape.