Because of a subjective observation that the surface "hardness" of West Virginia University's Mountainer Field, covered with Monsanto's AstroTurf, has progessively increased since its installation five years ago, impact absorption studies were carried out. Surfaces tested for comparison were new AstroTurf, five year old AstroTurf, a well kept grass field, and asphalt. Four impact parameters of each surface were measured; stopping time, total impact duration, peak acceleration and average acceleration. Sod was found to have the most superior impact absorbing qualities, followed closely by new AstroTurf. Five year old AstroTurf was found to have considerably less ability to absorb impact force, apparently due mainly to changes in the grass-like surface layer. A method of measuring impact absorbing capacity of athletic playing surfaces is described.
Keywords: artificial playing surfaces; hardness; deterioration with use and exposure