Study Design Research report- retrospective cohort.

Objectives To determine if differences in Y-Balance Test (YBT) scores exist between those that have sustained an ankle sprain (AS) and those that have not (C).

Background Ankle sprains are one of the most common injuries occurring in an athletic population. Many factors may contribute to the occurrence of an ankle sprain, including poor movement strategies and deficits in dynamic postural control.

Methods and Measures Thirty-six (30 male, 6 female) university student-athletes (age=18.4±0.7 years., height=178.2±6.8 cm, mass=88.6±20.8 kg); with AS (n=18) and C (n=18) participated. Single-limb reach distance was tested using the YBT in three reach directions; anterior (ANT), posteromedial (PM), and posterolateral (PL). Differences between limbs in each direction (ANTdiff, PMdiff, PLdiff) and the composite scores (COMPdiff), relative to limb length, were calculated. Our independent variable was group (AS vs. C) and the dependent variables included ANTdiff, PMdiff, PLdiff, and COMPdiff. Separate independent T-test analyses were performed to determine differences between means.

Results There was a significant difference in COMPdiff between AS (3.67%±2.51%) and C (2.35%±1.11%, p=0.05, t=3.57) and a moderate effect size (Cohen’s d=0.68). There were no significant differences in ANTdiff, PMdiff, or PLdiff.

Conclusions The difference in percentages between the two groups demonstrates the asymmetry present between the limbs. We can conclude that student-athletes with larger asymmetries in composite YBT scores may have sensorimotor impairments prior to an ankle sprain, leading to a difference in dynamic balance between their limbs. Unequal dynamic balance during activity may lead to the potential of further injury. This finding has a meaningful impact to clinicians that may implement this easy-to-use tool to determine the potential of developing a subsequent ankle sprain.