Intratester reliability and measurement error of the adapted crossover hop for distance

Objective: To determine the intratester reliability of the adapted crossover hop for distance in uninjured subjects. Design: Within-subject between-session repeated measures with random selection from a sample of convenience. Setting: University physiotherapy laboratory. Participants: Twelve subjects (male: n = 4; female: n = 8; age = 22.4 +/- 5.5 years; height = 168.7 +/- 5.2 cm; mass = 65.8 +/- 8.5 kg) without a history of lower limb or low back injury. Methods and Measures: Subjects performed three sub-maximal warm-up trials followed by three measured trials of the adapted crossover hop for distance utilising the self-reported dominant limb on two test sessions. The intraclass correlation coefficient (ICC) form (2,1), standard error of measurement (SEM), and 95% confidence interval (CI) were calculated utilising subjects' highest scores to determine intratester reliability and measurement precision. Results: The ICC (2,1) was 0.94. The SEM was 28.8 cm. The 95% CI was 56.5 cm. Conclusions: The results of this study demonstrate the adapted crossover hop for distance has high intratester reliability and acceptable measurement error in uninjured subjects. Thus, a new hop test with potential for identifying knee dysfunction in an anterior cruciate ligament (ACL)-injured population is presented. Future research should determine the reliability, measurement error, and validity of the adapted crossover hop for distance in an ACL-injured population. (C) 2002 Elsevier Science Ltd. All rights reserved.