Hammer Time: Management Practices and Field Surface Hardness.

Athlete safety should be the number one priority of any athletic field manager. Head to surface contact has been linked to approximately 10-15% of concussions in American football. The NFL now requires surface hardness testing before each game using an instrument called a Clegg Impact Tester. Field surface hardness(FSH) is tested by dropping a weight (hammer) from a fixed height onto the playing surface generating a number referred to as the Gmax. Each drop of the hammer must generate a number below 100 in order to pass NFL FSH guidelines. If a location generates a number above 100, steps must be taken in order to alleviate surface hardness before a game is played. At this time, no other level of play in American football requires FSH testing before games. The objectives of this study were to: determine if there is a correlation between FSH and volumetric water content (VWC) and determine compounding FSH measurements over a home collegiate football season. This study was completed on two collegiate NCAA football fields with each location being analyzed separately. Results show that FSH and VWC did not correlate at either test location over the 2016 home football season. We believe this is due to each location maintaining a high quality turfgrass stand and irrigating to field capacity each day. At each test site, there was a significant game x location interaction for each parameter tested. Each test site also showed a significant increase in FSH from the first home game to the last game of the season. We hope the results of this study will prove the need of further field testing on all levels of play.