a b s t r a c t Objective: Determine which ankle instability questionnaire predicts subject's ankle instability status based on a minimum accepted criteria for FAI (MC_FAI). Design: Cross-sectional study. Setting: Large Midwestern University. Participants: College aged subjects (n ¼ 1127 19.6 AE 2.1 years) from a university population were recruited for this study. Any volunteer, regardless of ankle injury history was included in the study. Main outcome measures: The independent variables were the score on three self-report ankle instability questionnaires: Ankle Instability Instrument, Cumberland Ankle Instability Tool, and Identification of Functional Ankle Instability. Subjects completed the questionnaires for their dominant limb during a single testing session. The dependent variable was created based on the previously established MC_FAI. This was established as at least one ankle sprain and at least one episode of giving way. Data were modeled using a chi-square and multinomial logistic regression. 95% confidence intervals were calculated for the resulting odds ratios. Results: A test of the full model with all three predictors against MC_FAI revealed that only the IdFAI (X 2 ¼ 457.09, p ¼ .001) had a significant relationship with the outcome variable. The IdFAI had an overall prediction rate of 87.8%. Conclusions: This analysis illustrates that IdFAI is a good overall option for predicting ankle stability status by self-reported questionnaire
