Cross-cultural adaptation, reliability, and validation of the Korean version of the identification functional ankle instability (IdFAI)

Purpose: To cross-culturally adapt the Identification Functional Ankle Instability for use with Korean-speaking participants. Methods: The English version of the IdFAI was cross-culturally adapted into Korean based on the guidelines. The psychometric properties in the Korean version of the IdFAI were measured for test-retest reliability, internal consistency, criterion-related validity, discriminative validity, and measurement error 181 native Korean-speakers. Results: Intra-class correlation coefficients (ICC_2,1) between the English and Korean versions of the IdFAI for test–retest reliability was 0.98 (standard error of measurement = 1.41). The Cronbach’s alpha coefficient was 0.89 for the Korean versions of IdFAI. The Korean versions of the IdFAI had a strong correlation with the SF-36 (r_s = −0.69, p <.001) and the Korean version of the Cumberland Ankle Instability Tool (r_s = −0.65, p <.001). The cutoff score of >10 was the optimal cutoff score to distinguish between the group memberships. The minimally detectable change of the Korean versions of the IdFAI score was 3.91. Conclusion: The Korean versions of the IdFAI have shown to be an excellent, reliable, and valid instrument. The Korean versions of the IdFAI can be utilized to assess the presence of Chronic Ankle Instability by researchers and clinicians working among Korean-speaking populations.Implications for rehabilitation The high recurrence rate of sprains may result into Chronic Ankle Instability (CAI). The Identification of Functional Ankle Instability Tool (IdFAI) has been validated and recommended to identify patients with Chronic Ankle Instability (CAI). The Korean version of the Identification of Functional Ankle Instability Tool (IdFAI) may be also recommend to researchers and clinicians for assessing the presence of Chronic Ankle Instability (CAI) in Korean-speaking population.