Validity and Reproducibility of the Sargent Jump Test in the Assessment of Explosive Strength in Soccer Players

The purpose of this study was to check the validity and the intra- and inter-evaluators reproducibility of the Sargent Jump Test, as an instrument of explosive strength measurement of soccer players of the sub-15 class. Forty-five soccer players were randomly selected from different clubs competing in the local soccer championship. All subjects performed one test on the same jump platform model Jumptest(®) (Hidrofit Ltda, Brazil) and two independent Sargent Jump Tests assessed by the same evaluator. Two days later, another Sargent Jump Test was performed simultaneously assessed by 2 evaluators. In all tests, three jumps were performed and the highest one was registered. In order to check the validity, the first Sargent Jump Test results were compared to those from the jump platform, considered the gold standard. To evaluate intra- and inter-evaluator reproducibility, results from the first, second and third Sargent Jump Tests were analyzed. The validity and reproducibility were evaluated by intraclass correlation coefficients (ICC), and by the Bland and Altman test (statistical pack SPSS 11.0), with a significance level set at p<0.05. The values found for validity (r=0.99, p=0.001), for intra-evaluator reproducibility (r=0.99, p=0.001) and for inter-evaluator reproducibility (r=1.0, p=0.001), permitted us to conclude that the Sargent Jump Test is a valid and reproducible instrument for measuring the explosive strength in homogeneous groups, such as those used in the present study.