Test MethodValidity and reliability of two standard test devices in assessing mechanical properties of different sport surfaces

The Artificial Athlete (AA) and the Advanced Artificial Athlete (AAA) devices are the two key test methods for the assessment of shock absorption (SA) and vertical deformation (VD) of sports surfaces. The aim of this study was to investigate the relationship between them. Laboratory tests were carried out in accordance with international regulations and standards on 50 athletics tracks and 44 artificial turf systems using both test methods. No significant differences between methods were observed. Measurements with the AA and the AAA were compared using intraclass correlation coefficients (ICCs), showing acceptable to excellent inter-method reliability (ICC ranged from 0.47 to 0.91). The Bland-Altman test revealed an overall SA overestimation and VD underestimation with the AAA. Linear regression analysis was performed, obtaining excellent agreement between test methods for the assessment of SA (R2 = 0.994) and VD (R2 = 0.985). It is concluded that, by applying Equations (1) and (2) in this study, the AA and the AAA could be used interchangeably when assessing SA and VD on athletics tracks and artificial turf surfaces.