Evaluation of reliability and sensitivity of the Y-balance test for quantifying lower limb asymmetry in prepubescent soccer and basketball players

Abstract

The Y-balance test (Y-BT) is a dynamic test that requires strength and proprioception and has been used to assess physical performance, identify chronic ankle instability, and identify athletes at greater risk for lower extremity injury. To date, research concerning the sensitivity and reliability of the Y-BT has been conducted only for adults. The aim of this study was to determine the reliability and sensitivity of the Y-BT maximal reach distances and their relationships with hamstring flexibility in young male team sport athletes. A total of 151 (78 basketball players and 73 soccer players) prepubescent soccer and basketball players, participated to this study. Hamstring flexibility was assessed using the sit and reach test. The intraclass correlation coefficient (ICC3,1) of the Y-BT maximal reach distances and composite scores for dominant and non-dominant legs ranged from 0.97- 0.98 and the standard error of measurement (SEM%) was <5% (0.55-1.47%). Moreover, the capacity to detect change was rated as ‘‘good’’ because the SEMs (0.007-0.94 cm) were smaller than the respective SWCs (0.01- 1.52 cm). There were no significant or meaningful correlations between Y-BT with the sit and reach test performance (p>0.05). The unpaired Student t-test revealed that dominant leg dynamic limits and composite scores were greater than those of non-dominant leg (p<0.05). This result was rejected by a small dz (<0.46) and an area under the ROC curve <0.7. According to the results of the study, the Y-BT dynamic limits and composite scores have excellent reliability but poor discriminate ability when used in prepubescent male soccer and basketball players.