Test-retest reliability of a dance-specific jump test using wearable technology among university contemporary dancers

A dance-specific jump test utilizing inertial measurement units (IMUs) to determine limb symmetry indices (LSI) may prove useful for clinicians responsible for dancer populations. The aim of this study was to determine test-retest reliability of a dance-specific jump test using wearable technology to capture limb asymmetry in university contemporary dancers. Nineteen female undergraduate dance majors participated in two testing sessions one week apart. IMUs (Vicon Motion Systems, UK) were attached to the distal anteromedial aspect of each tibia and at the L5/S1 joint. Participants performed three jumps: countermovement jump (CMJ), a single leg side hop (SH), and a dance-specific jump (DSJ). Test-retest reliability of asymmetry measures [i.e., peak impact acceleration (g), mean asymmetry (%)] and performance measures [i.e., flight time (sec), time to completion (sec), and jump height (cm)] were estimated using intraclass correlation coefficients [ICCs (95% CI)] and Bland Altman methods of agreement [95% limits of agreement (LOA)]. For asymmetry measures, reliability was poor for CMJ [ICC 0.36 (95% CI -0.08-0.77)], moderate for SH [ICC 0.66 (95% CI 0.35-0.88)] and good for DSJ [ICC 0.82 (95% CI 0.49-0.94)]. Wide 95% LOA were demonstrated for all jumps. For performance measures, moderate to good reliability and acceptable LOA were found for all jumps. While a lack of agreement was found for asymmetry measures, sufficient reliability and acceptable agreement were established for performance measures for all jump tests in university contemporary dancers. This method may be used to monitor the performance of jumps and jump load throughout a training season.