Performance-based outcomes such as the T-Test, Edgren Side Step Test (ESST), and Illinois Agility Test (IAT) have been used to assess agility in athletes and nonathletes; however, the reliability and validity of these tests have not been established. The purpose of this study was to establish the reliability and convergent construct validity of the ESST, T-Test, and IAT in young, nondisabled, physically active male servicemembers (SMs). Ninety-seven male Active Duty U.S. Army SMs completed the study. Statistically significant differences were not found between the ESST (p = 0.10), T-Test (p = 0.09), and IAT (p = 0.23) when administered twice within a 24 to 48 h period. These tests were found to have excellent interrater reliability and moderate to good test-retest reliability. A good positive relationship exists between the IAT and T-Test (r = 0.76, p < 0.001) and a moderate negative relationship exists between the ESST and both the T-Test (r = -0.69, p < 0.001) and IAT (r = -0.65, p < 0.001). The results suggest that these tests are valid measures of agility that uniquely assess movement in different planes, thus providing a comprehensive assessment of high-level mobility.
Keywords: Edgren Side Step Test; Illinois Agility Test; T-Test; agility; military; minimal detectable change; reliability; servicemembers; standard error of measurement; validity.