Translation, cross-cultural adaptation, and measurement properties of the Brazilian version of the Identification of Functional Ankle Instability (IdFAI) questionnaire

•IdFAI is an accepted instrument to be used across different languages and cultures.•The Brazilian version of the IdFAI is a helpful instrument to determine CAI.•IdFAI contribute to the standardization of CAI populations from different countries.•IdFAI-Brazil showed excellent validity, internal consistency and agreement.•IdFAI-Brazil is a reliable instrument to be used by different evaluators.