Test-Retest reliability of performance, knee functionality and movement quality biomechanics in agility T-test using markerless motion capture

Abstract

The purpose of this study was to assess reliability of performance, knee functionality and movement quality parameters in agility T-test using markerless motion capture. Seventeen healthy participants performed two sessions of agility T-test with a one-week interval. Performance, knee functionality and movement quality parameters were evaluated for absolute reliability between sessions for discrete metrics. Test-retest reliability was evaluated using intraclass correlation coefficient (ICC (2,1), absolute agreement), standard error of measurement (SEM), and minimal detectable change (MDC). The between-session ICC values of performance, knee functionality and movement quality parameters showed moderate to good reliability (ICC range performance parameters: 0.65–0.96; ICC range knee functionality parameters: 0.74–0.94; ICC range movement quality parameters: 0.59–0.90). SEM and MDC provided insights into precision and minimal clinically significant changes for each parameter. Overall, these findings support the potential of markerless motion capture for reliably quantifying the evaluated biomechanical parameters during the agility T-test, demonstrating consistent test–retest reliability across sessions.