Original Artificial Turf
Artificial turf, first used in the 1960s as a way to reduce maintenance for playing fields, has often been blamed for increased injuries to athletes. AstroTurf, an early artificial surface constructed of nylon, was proven in a 1992 study by John Powell at the University of Iowa to cause NFL players to suffer more serious knee injuries than players competing on natural grass. Other complaints included sore muscles, concussions, sprained ankles, turf burns, and "turf toe," which is pain in the big toe caused by jamming against the turf.
Advancement of Artificial Turf
A key advancement in the manufacture of artificial turf has been the use of "infill" as is used in the popular newer surface FieldTurf. Infill is made up of tiny pellets of rubber or silica, which can be mixed with sand and fills in the spaces in the turf, acting as dirt might on a real grass playing field, and allowing more give and flexibility. Modern fields also better simulate real grass blades, and are adjusted based on the needs of the players and the sport for which the field is used. Players report better "playability," but controversy remains over how well even modern turf protects players from injury. General concerns about artificial turf, even newer playing fields, include questions about the lead level and about the carcinogenic properties of the infill. Increased heat can create problems for players in hot weather, because the temperature on artificial turf can be over 15 degrees hotter than the temperature on real grass. Infection of cuts and burns can also put players at risk since turf does not have the same anti-microbial qualities as real grass.
Turf-Related Injuries
Scientists pinpoint two key causes of injuries due to artificial turf: the "coefficient of friction," and the "coefficient of restitution." The friction issue relates to how difficult it is for a player to move once he makes contact with the turf. Feet feel as if they are stuck on the turf, and higher rates of ACL (anterior cruciate ligament) injuries of the knee may occur. The turf's restitution concerns how well a surface can absorb shock. Artificial turf can absorb shock better than, for instance, a slab of concrete, but not as well as real grass, putting players at risk after hard landings. Studies to measure the risk of head injuries on various playing surfaces yielded results favorable to both grass and turf. When Dr. Roseanne Naunheim at Washington University School of Medicine conducted tests comparing artificial surfaces AstroTurf and FieldTurf at various levels of padding with real grass, the frozen real grass field was the most dangerous for head injuries. FieldTurf was not a clear winner, either; as the infill of the FieldTurf became more compacted, it lost its edge over older AstroTurf that was appropriately padded.
Tags: real grass, artificial turf, absorb shock, Artificial Turf, head injuries, players risk, playing fields