The grass vs. turf debate in sports activities: What the science says

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By Calvin S. Nelson

Which enjoying floor is safer for athletes: pure grass or synthetic turf?

The query is vital not simply in , but additionally for soccer, leisure sports activities and highschool and school athletics — anyplace athletes make sudden shifts in route that may twist joints and tear ligaments.

Scientists proceed to review the query, however there are challenges to getting the reply proper. There are variables to have in mind: the participant’s age and bodily form, climate and floor situations, the kind of sneakers and whether or not the accidents concerned contact with different gamers. And surfaces have modified over time with new expertise.

The controversy was revived when Aaron Rodgers tore his Achilles’ tendon throughout an NFL recreation on synthetic turf. Though Rodgers’ harm could have been simply as doubtless on grass due to the circumstances, that hasn’t stopped the wrangling.

What does the science say and what are the challenges?

Some research look again at harm charges, whereas making changes for different components that might be in play. That kind of examine is nice, however won’t ever be capable of sustain with innovation, mentioned Dr. Calvin Hwang, a staff physician for Stanford’s gamers and the San Jose Earthquakes soccer staff.

“There’s at all times evolving expertise, each with grass, however particularly with synthetic turf,” Hwang mentioned. “The newer technology turfs could also be safer than older technology turfs. And so research that had been executed 5 – 6 years in the past might not be together with a few of these newer technology turfs.”

Nonetheless, Hwang, who treats gamers who play residence video games on grass, mentioned the analysis he’s seen leads him to imagine that grass is safer.

Lately, a gaggle of researchers reviewed research on the subject. They checked out 53 articles revealed between 1972 and 2020, on accidents in skilled and novice sports activities, together with , soccer, rugby, area hockey and supreme Frisbee. The authors did not specify whether or not the research included accidents involving a direct blow from one other participant, or simply non-contact accidents.

The research recommend “a better charge of foot and ankle accidents on synthetic turf, each old-generation and new-generation turf, in comparison with pure grass,” they wrote in a paper revealed final 12 months within the American Journal of Sports activities Medication. Knee and hip accidents had been comparable on each surfaces, they wrote. The authors famous that research reporting a better charge of harm on grass obtained monetary help from the bogus turf business.

Related findings had been reported in a separate examine that analyzed 4,801 NFL foot and leg accidents throughout 2012-2016 common season video games. That analysis discovered 16% extra accidents per play on synthetic turf in comparison with grass. The authors concluded that if all video games had been performed on grass throughout that interval there would have been 319 fewer foot and leg accidents. Wanting solely at non-contact accidents the danger was even increased, about 20% extra accidents per play.

Within the NFL, the gamers’ union prefers grass and has been pushing for it. The NFL says some synthetic turf fields are safer than some grass fields and desires to cut back accidents on all surfaces. About half the NFL stadiums use synthetic turf.

Each side use the identical information on non-contact harm charges, however have interpreted the figures in another way.

The information collected for the NFL and gamers union shouldn’t be publicly out there. The corporate that analyzes the info, IQVIA, didn’t reply to a number of requests for remark.

Synthetic turf is constructed from plastic fibers that resemble grass with a cushioning infill product of granulated rubber, sand, cork or coconut fiber.

“The upside of turf is that gamers really feel extra nimble, they really feel quicker,” mentioned Dr. Brian Cole, orthopedic surgeon and staff physician for basketball’s Chicago Bulls. “The draw back is that they’re quicker. It’s a collision sport. Velocity goes up and collisions go up.”

Dr. Joseph Donnelly has repaired quite a few torn ACLs in feminine highschool soccer gamers within the Bay Space the place most highschool athletes play on synthetic turf. Feminine athletes are extra doubtless than males to undergo ACL accidents in sports activities resembling soccer that require sudden adjustments in route, research have proven.

“It’s an epidemic,” mentioned Donnelly, an orthopedic surgeon at Stanford Well being Care. “When these women tear their ACLs, we repair them, we ship them again after which they’re really extra more likely to tear their reverse ACL.”

He dug into the analysis. One examine from 2016 used a hydraulic testing machine to simulate sneakers with completely different fashion cleats pivoting on numerous enjoying surfaces. Sneakers with blade-shaped cleats on synthetic turf had been a harmful mixture. The traction from the blade-shaped cleats elevated the twisting drive on the knee.

“You’re not going to have the ability to change the floor you play on,” Donnelly mentioned. “So we do attempt to get them to make use of a cleat that has a good interplay with the turf.”

Some younger athletes don’t wish to surrender their favourite cleats as a result of they fear about efficiency on the sphere, he mentioned. Like different sports activities drugs specialists interviewed for this story, he thinks grass is safer.

“There’s no query that there’s much less torque whenever you’re on grass it doesn’t matter what cleats you’re sporting,” he mentioned.

For large stadiums, apart from participant security, there are monetary pressures that favor synthetic turf, which provides extra flexibility for occasions like concert events. Climate and maintenance are a part of the equation. A poorly maintained grass area may cause accidents.

The longer term could also be hybrid fields. The Inexperienced Bay Packers’ Lambeau Subject in Wisconsin has featured Kentucky bluegrass sod weaved in with artificial fibers since 2018.

Grass or hybrid fields could get a lift from the 2026 World Cup. The laws for the event haven’t but been revealed, however grass has been most popular for all previous males’s World Cups. Seven of the 11 U.S. venues are NFL stadiums with synthetic turf. And in a latest ESPN interview, NFL Commissioner Roger Goodell mentioned the stadiums will likely be placing in hybrid surfaces for the event.

Grass area expertise has improved, Cole mentioned. “They’ll do it when it’s 110 (levels) they usually can do it when it’s 30 under zero in Inexperienced Bay. So it may be executed. And I believe the science is clearly enabling them to do it at this level.”


The Related Press Well being and Science Division receives help from the Howard Hughes Medical Institute’s Science and Instructional Media Group. The AP is solely liable for all content material.

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