Purpose: The Y Balance Test (YBT) is a screen of dynamic balance requiring stance leg balance while the contralateral leg reaches in anterior (ANT), posteromedial (PM), and posterolateral (PL) directions. YBT has been proposed as a screen for injury risk however limited research has examined the association between YBT and injury. The purpose of this study was to examine the association between YBT (asymmetry and composite score [CS]) and non-contact injury in a sample of Division I (DI) college athletes from multiple sports.
Methods: DI college athletes were screened with the YBT during the pre-participation examination to determine asymmetry (absolute difference between legs in ANT, PL, and PM) and CS (summed average of right/left ANT, PL, and PM normalized to leg length). Participants were followed throughout the sport season and non-contact injuries requiring athletic training staff intervention were recorded for analysis. Demographic variables between injured and not injured were assessed with independent t-tests. Receiver operating characteristic (ROC) curves determined optimal cut-points for predicting injury based on CS and asymmetry. CS was analyzed as a continuous variable as ROC curves were unable to maximize sensitivity and specificity. Logistic regression models adjusted for sport and previous injury determined the odds of injury based on asymmetry and CS.
Results: 184 participants were included in analysis: 81 were injured. ROC curves determined asymmetry > 4 cm (Sensitivity=59%; Specificity=72%) as the optimal cut-point for predicting injury. Only ANT asymmetry was significantly associated with non-contact injury (odds ratio=2.33, 95% confidence interval [1.15-4.76]).
Conclusion: ANT asymmetry > 4 cm was associated with increased risk of non-contact injury. CS in this sample of DI athletes was not associated with increased risk of injury.
(C) 2014 American College of Sports Medicine