By Kathleen Raven
NEW YORK (Reuters Health) - Female soccer players suffered fewer severe injuries while competing on an artificial surface called FieldTurf than when playing on natural grass fields, in a new study.
Researchers found women's college teams had an average of 7.7 injuries - both minor and serious - for every 10 matches played on FieldTurf, compared to 9.5 injuries per 10 matches on grass. Most competitive collegiate soccer seasons consist of 20 to 25 matches.
The findings suggest "FieldTurf is a practical alternative to natural grass," study author Michael Meyers of Idaho State University in Pocatello told Reuters Health.
Early versions of synthetic turf that appeared in the late 1960s and 1970s were sometimes little more than a layer of thick, carpet-like material laid over concrete, he said. In today's U.S. artificial surface market, more than 30 companies compete with proprietary mixes of what the industry calls "infill systems," which can include rubber, silica sand and polyethylene fibers.
Montreal-based FieldTurf, which funded 40 percent of the current study, relies on a blend of silica sand and cryogenically ground rubber for its fields.
Estimates vary, but artificial field turf surfaces can last up to 10 years, with initial installment costs ranging from $800,000 to $1 million and annual maintenance fees of about $2,500.
"As the impact of the game increases, as the adverse weather worsens, FieldTurf provides a more consistent surface," than grass fields, said Meyers, who does not own any stock in the company.
The new study, published in The American Journal of Sports Medicine, is based on injury data from nearly 800 matches reported by athletic trainers at 13 universities classified as National Collegiate Athletic Association (NCAA) Division IA. Women's soccer programs that spent nearly equal competition time on FieldTurf and natural grass were included.
There were 693 injuries recorded during the five-year study period, including 130 substantial or severe injuries.
Substantial injuries requiring one to three weeks off were twice as common on natural grass as turf, Meyers found.
In his analysis, he considered the athlete's weight, shoe cleat design, weather conditions, position played at the time of injury, the age of the field itself and the surface temperature.
The current study is "remarkably comprehensive," said Glen Livesay, a biomedical engineer at Rose-Hulman Institute of Technology in Terre Haute, Indiana.
Livesay, who was not involved in the current study, has investigated FieldTurf in his own research. He told Reuters Health similar experiments completed in lab environments tend to use simple, repetitive motions done at a slower pace compared to real-life games.
The study's findings run counter to another report that found a higher rate of anterior cruciate ligament (ACL) injuries on FieldTurf compared to grass surfaces for National Football League players (see Reuters Health story of September 14, 2012 here: http://reut.rs/1dN8J1Z).
A separate 2012 study of data from the NCAA's Injury Surveillance System on football games arrived at a similar conclusion regarding ACL injuries.
Meyers' findings do point in the same direction, however, as a 2007 British study that found no differences in injury rates among male and female soccer players on artificial turf versus grass surfaces.
Researchers agreed it's difficult to make comparisons between different sports, genders, playing levels and surface types.
Livesay said the current study could have been improved by looking at practice fields used by soccer teams to determine possible correlations between changing field types from practice to competition and injury incidence.
The current study is "another important piece in the puzzle, but it's not the whole answer," Dr. Samuel Taylor, an orthopedic fellow at the Hospital for Special Surgery in New York, who did not participate in the new research, told Reuters Health.
"It's difficult to make generalizable comparisons because so many factors go into the interaction between the type of turf and different injury types," he said.
SOURCE: http://bit.ly/1dN3H5n The American Journal of Sports Medicine, online August 13, 2013.