DIFFERENCES IN GROUND REACTION FORCES WHEN PERFORMING THE SIDE-STEP CUTTING ACTION ON DIFFERENT INFILL DEPTHS

Abstract

This study aimed to quantify differences in ground reaction forces (GRFs) when performing a side-step cutting action on artificial grass turf with two different infill depths. GRFXPeak (7.27 ± 2.7 N/kg vs. 9.00 ± 2.7 N/kg, p=0.00) and GRFYPeak (5.41 N/kg ± 1.4 vs. 6.15 N/kg ± 1.6, p=0.00) were significantly larger, but not GRFZPeak (28.26 N/kg ± 8.6 vs. 29.64 N/kg ± 9.3, p=0.58) when participants (n=17) performed side-steps on turf with greater infill depths. Larger GRFZPeak during heel-strike may be due to larger knee extension angle (39.7 deg ± 8.2 vs. 34.7 deg ± 8.5, p=0.03) while significantly larger GRFXPeak and GRFYPeak at the weight acceptance phase and push-off phase may be due to a larger knee extension angle in conjunction with the hardness of sand/rubber infills given the increased thickness as well as frictional components of the artificial grass turfs.