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Association of Y Balance Test Reach Asymmetry and Injury in Division I Athletes


Medicine & Science in Sports & Exercise: January 2015 - Volume 47 - Issue 1 - p 136–141
doi: 10.1249/MSS.0000000000000380
Applied Sciences

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 noncontact injury in a sample of Division I (DI) college athletes from multiple sports.

Methods DI college athletes were screened with the YBT during the preparticipation 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 noncontact injuries requiring athletic training staff intervention were recorded for analysis. Demographic variables between injured and uninjured athletes were assessed with independent t-tests. Receiver operating characteristic (ROC) curves determined optimal cut points for predicting injury on the basis of 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 on the basis of asymmetry and CS.

Results One hundred and eighty-four 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 noncontact injury (odds ratio, 2.33; 95% confidence interval, 1.15–4.76).

Conclusions ANT asymmetry >4 cm was associated with increased risk of noncontact injury. CS in this sample of DI athletes was not associated with increased risk of injury.

1Department of Physical Therapy and Athletic Training, Northern Arizona University, Flagstaff, AZ; 2Proactive Physical Therapy, Tucson, AZ; and 3Athletic Training Department, Daemen College, Amherst, NY

Address for correspondence: Meghan Warren P.T., M.P.H., Ph.D., Department of Physical Therapy and Athletic Training, Northern Arizona University, PO Box 15105, Flagstaff, AZ 86011; E-mail:

Submitted for publication December 2013.

Accepted for publication May 2014.

© 2015 American College of Sports Medicine