Ask a Sports Medicine Doc column: Turf or grass?
July 2, 2013
Question for Dr. Cunningham: My daughter plays soccer regularly on a turf field. I've heard that athletes are at greater risk of injury playing on artificial fields. Is this true?
— Turf versus Grass, Eagle County
Dear Turf versus Grass,
The American Academy of Orthopaedic Surgeons recently published a paper on this topic titled "Synthetic playing surfaces and Athlete's Health" (Drakos, May 2013). The article does a good job of outlining both the risks and benefits of turf fields yet summarizes the issue by stating "the health and injury ramifications have yet to be clearly defined."
Turf fields were first used in athletics in the 1960s. You may remember the Houston Astrodome and its turf field, which was installed in 1966. Turf fields have been heavily relied on in urban environments where grass fields might not be available and where multiple sporting activities can be conducted on just one artificial field.
Turf fields have the advantage of less maintenance and can be used around the clock without the damage that one would see after such use of a grass field. Turf fields have the advantage of providing a consistent surface. Most of us have played on grass fields where the surface is uneven. I personally injured my own knee as a teenager while playing soccer when I stepped in a hole on a grass field that had seen excessive use.
Turf fields are particularly popular here in the high country because they are more durable than grass fields with regard to snow and seasonal weather conditions. We are fortunate in Eagle and Summit counties to have the latest generation turf fields, which are made from a mixture of rubber and sand; these more closely approximate playing on grass and are safer for athletes.
A 2012 study suggesting that turf fields caused higher injury rates as compared to grass fields has fueled concern among all types of players as well as parents of student athletes.
Indeed, the American Academy of Orthopaedic Surgeons article points out that "historically, clinical studies have indicated that higher injury rates occur on artificial turf than on natural surfaces. This reason is that biomechanical data suggests that torque and strain may be greater on artificial surfaces than on natural grass."
It's important to note that dramatic improvements have been made with respect to synthetic playing surfaces in recent years. Unlike the turf fields of the 1960s, the fields that are constructed today are considered third generation with more equivocal risks than earlier generations. Although I see serious orthopedic injuries from players injured on turf fields, I have not seen more injuries from playing on turf than grass, except for a higher instance of abrasions sustained on turf fields.
As for limiting the risk of injury, I recommend that athletes use turf shoes and not regular cleats when playing on turf. There is a higher level of torque across one's ankle or knee when cleats are used instead of turf shoes with smaller cleats. One should also avoid cleats on the sides of the sole of the shoe, as one study showed a higher incidence of ACL tears with this particular cleat pattern.
Although I do not see a higher incidence of musculoskeletal injury on turf fields compared to grass fields, turf fields do present some other potential health risks. There may be a greater risk of concussions, particularly on older generation artificial surfaces given their harder surface. There is some concern for the communicability of bacterial and fungal illness, so athletes should clean any cuts or abrasions well after playing. Finally, there is a more theoretical risk of carcinogenicity related to the crumb rubber infill used in third-generation turf fields, but there is no convincing data to substantiate this as a true risk.
In summary, the American Academy of Orthopaedic Surgeons states that "confounding variables such as weather conditions, contact versus noncontact injuries, shoe wear and field wear make it difficult to definitively state the true risk of certain shoe-playing surface combinations". Clearly, the health and injury ramifications of artificial turf have yet to be defined.
Dr. Rick Cunningham is a knee and shoulder sports medicine specialist with Vail-Summit Orthopaedics. He is a physician for the U.S. Ski Team and chief of surgery at Vail Valley Medical Center. Do you have a sports medicine question you'd like him to answer in this column? Visit his website at http://www.vailknee.com to submit your topic idea. For more information about Vail-Summit Orthopaedics, visit http://www.vsortho.com.