A New Device for Simulating Athlete-to-Surface Interactions On Natural and Synthetic Turf.

Instruments simulating player-to-surface interactions on athletic fields often evaluate either horizontal or vertical force separately. The Tennessee Athletic Field Tester (TAFT) was developed to provide researchers with an instrument for evaluating natural and synthetic turf that simultaneously generates the peak vertical and horizontal forces that occur during player-to-surface interactions.  TAFT consists of an extrusion aluminum framework and foot assembly that generates vertical and horizontal forces using pneumatic cylinders and a linear actuator.   Peak vertical and horizontal force data were collected while operating TAFT on a force platform in the University of Tennessee biomechanics laboratory (Knoxville, TN). TAFT data were collected using three player weights (75 kg, 85 kg, and 95 kg) and horizontal velocities (500 mm s^-1, 750 mm s^-1, and 1000 mm s^-1).  At 1000 mm s^-1, peak vertical force values were greater than or equal to those captured by the force platform and similar to those reported using human subjects of similar weight. All testing configurations for TAFT generated peak horizontal forces greater than the force platform and higher than have been observed in human subject trials. TAFT is a new testing device for evaluating natural and synthetic playing surfaces and it is capable of producing both vertical and horizontal forces that occur during player-to-surface interactions.