Reliability and validity of the Sargent jump in people with intellectual disabilities.

BACKGROUND: Assessing muscular strength in people with intellectual disabilities requires simple and reliable field tests. This study analysed the reliability and validity of the vertical jump (VJ) across disability levels. METHOD: Sixty-three participants with intellectual disabilities completed the VJ, standing long jump (SLJ), and countermovement jump (CMJ) twice in separate sessions. Relative and absolute reliability were assessed using the ICC and SEM/MDC, respectively. Validity was examined using Pearson's correlations. RESULTS: The VJ showed good relative reliability (ICC = 0.89) but poor absolute reliability (%SEM = 16.4). The SLJ (ICC = 0.92) and CMJ (ICC = 0.94) showed excellent reliability. Correlations were fair between the VJ and CMJ (r = 0.44) and fair to moderate between the VJ and SLJ (r = 0.56-0.69). CONCLUSION: The VJ demonstrated good reliability but limited validity, whereas the SLJ was more reliable and valid for assessing lower-body strength in people with intellectual disabilities.