Football ACL Injuries About Equal On Grass Versus AstroTurf®

Courtesy of Sports Medicine & Football: The 2006 Perspective
Presented by Dr. James P. Bradley
May 13, 2006

The number of anterior cruciate ligament (ACL) injuries suffered by football players on natural grass or on AstroTurf® is about equal, but more research is needed on ACL injury prevalence on newer playing surfaces, according to a presentation given today during a meeting of NFL and NCAA team physicians and athletic trainers in Hollywood, Fla.

James P. Bradley MD, head team physician for the Pittsburgh Steelers, has studied ACL injuries in the NFL and reports that while the prevalence of those injuries is about the same on the two playing surfaces (grass vs. AstroTurf®), it remains to be seen whether the rate of ACL injury will change due to newer artificial surfaces.

"When we look at incidence, there are actually more ACL injuries occurring on natural grass," explains Dr. Bradley, "That's because more teams practice and play on grass than on artificial surfaces. However, when we look at ACL injuries by exposure we have found no real differences between grass and AstroTurf®."

Although AstroTurf has largely been replaced by other synthetic surfaces in pro stadiums, it is still widely used on high school fields, Dr. Bradley says.

According to Bradley, 82 percent of ACL injuries occur on natural grass during practice than on artificial turf (18 percent). Again, Dr. Bradley points to the fact that most teams practice on grass. "But when you look at the little things that can happen, the bumps and bruises, there are fewer overall injuries on grass than on any other surface," he says.

"Everyone thinks there has been an increase in ACL injuries in pro football," Dr. Bradley states. "Our research over the past 17 years shows the rate of ACL injuries has stayed constant, at about 2 percent per year."

In the last five years, knee and ankle sprains have been the most common injuries in the NFL in terms of sheer numbers, but a torn ACL (ranked No. 17 in specific diagnosis) is the number one time loss injury. Most NFL teams can expect one or two players to experience an ACL injury every year, Bradley says, and the league average is 35-40 ACLs per year.

(The ACL is one of four ligaments in the knee, connecting the front top part of the shin bone to the back bottom part of the thigh bone and keeps the shin from sliding forward and rotating. Damage to the ACL typically occurs through a twisting mechanism, such as when a running athlete changes direction quickly.)

Other findings of Dr. Bradley's research on ACL injuries in the NFL:

-- Most injuries are likely to occur in either the second or third quarter ("We don't know why for sure, but perhaps a lot of games are 'decided' before the fourth quarter, so the effort may not be the same later in the game.")

-- Running backs are at highest risk on offense; on defense, the linesmen are at highest risk. However, of all positions, the kicking unit suffers the most ACL injuries.

-- Most ACL injuries are non-contact injuries, not as a result of being tackled. ("It happens when the athlete tries to 'cut' quickly and his foot gets stuck in the turf.")

-- The average ACL injury takes six to nine months to heal properly ("probably a full year. When surveyed, 90 percent of NFL team physicians believe that, if treated correctly, between 90-100 percent of players successfully return to play in the NFL after an ACL injury.")

Dr. Bradley and colleagues on the NFL Foot and Ankle Subcommittee are also investigating the relationship between footwear, playing surface and the incidence of ACL injury. The subcommittee has been working with major athletic shoe manufacturers to develop footwear that would be appropriate to each type of playing surface to reduce the number of ACL injuries. "We can't tell a player what (shoe) to wear," Bradley says, "but our research may show which footwear might be best for the type of playing surface and for specific weather conditions."

Bradley says that NFL Charities awards over $1 million dollars in grants each year to study football injuries and related health issues. "This league cares about its players and is doing everything it can to make the sport safer," Dr. Bradley says. "If we can reduce the number of ACL injuries by even half, that will really benefit the game."

Dr. Bradley gave his presentation at the conference, "Sports Medicine & Football: The 2006 Perspective," co-sponsored by the American Orthopaedic Society for Sports Medicine (AOSSM) and the National Football League Physicians Society, and supported by the National Athletic Trainers' Association and the National Football League. AOSSM, based in Chicago, Ill., is a membership organization of orthopaedic surgeons, athletic trainers, physical therapists and other health professionals who specialize in the care and treatment of athletes and active individuals. Over 90 percent of the Society's members serve as team physicians on the pro, collegiate or high school levels, and many serve as team physicians for Olympic sport teams. Please visit http://www.sportsmed.org .