Frank S. Rossi

Associate Professor and Extension Turfgrass Specialist

Frank Rossi, associate professor at Cornell University, is an expert on turfgrass management. He says grass type had little to do with it.

Rossi says:

“In my judgement, grass type had little if anything to do with surface performance. Surface performance is rather affected by the environment – an indoor, low light, mostly enclosed stadium, with 72,000 fans – on grass that routinely moves outside then back inside. Specifically, this environment can allow humidity to increase at the field level and with minimal air movement can make the surface slick. If the athletes don’t plant their feet properly on the slick surface they slip.

“This is a critically important difference between natural and synthetic turf. Synthetic turf allows for maximum traction (based on shoe type) and therefore little, if any, slipping. Which means the energy the foot puts into the field with a cut/as they run, is transferred back into the lower extremities and that is why synthetic turf has a 24% increased chance of non-contact lower extremity injury.

 “The fields are tested by the NFL for traction with a device that simulates an athlete putting their cleat properly into the turf and measures shear strength. I’m sure when a cleat got planted directly in the turf, the Tahoma 31 (overseeded with ryegrass), they didn’t slip. While both teams play on natural grass at home (KC and Philly) they play outside where sun and wind can influence the surface. They also play on a lot of synthetic turf where planting their foot the way they did last night did not result in the same outcome-they slipped.

“Interestingly, there were no lower extremity injuries and offenses were very productive, as were special teams. There is data from Australian rules football that has shown players are more likely to prefer to play on surfaces that allow them to perform at a high level (faster, better cuts) and they are also more likely to suffer non-contact injuries on the surfaces they prefer.”