Interrater, Test-retest Reliability of the Y Balance Test: A Reliability Study Including 51 Healthy Participants

The aim was to determine the relative and absolute interrater, test-retest reliability of the Y-Balance Test (YBT) in a sample of healthy and active adults aged 18 to 50 years. The sample consisted of 51 healthy and active participants, 30 men and 21 women with a mean age of 28 ± 7 years. The YBT was performed on the right leg in the three test directions. Test and retest of the YBT were performed with a median interval of 15 days. The method for data collection was in line with the Y Balance Test Lower Quarter Protocol (YBT-LQ). The test was conducted by raters previously inexperienced in the use of the YBT. The relative reliability was reported as Intraclass Correlation Coefficient (ICC_(2,1)). The absolute reliability was reported as Standard Error of Measurement (SEM) and Minimal Detectable Change (MDC). The ICC ranged from 0.79-0.86. SEM ranged from 2%-4%, indicating the measurement error at group level and MDC ranged from 5%-11%, indicating the measurement error at individual level. The YBT showed good relative and absolute reliability. The YBT is therefore considered suitable at both group and individual level in physically active populations.