Materials and method: The cross-cultural adaptation was conducted based on standard guidelines to produce the Malay version of the Identification of Functional Ankle Instability (IdFAI-M) questionnaire. The reliability and validity testing were then performed among one hundred and twenty-three physically active University of Malaya students. Among them, twenty-two students also participated in the second return of the questionnaire over a two-week interval, which was then evaluated for test-retest reliability testing.

Results: The content validity for item-level (I-CVI) and Kappa values for all items were more than 0.7, respectively and the all scales-level (S-CVI) values were 0.983 (consistency), 0.967 (representativeness), 1.00 (relevance) and 0.983 (clarity). The questionnaire also demonstrated excellent reliability with an intraclass correlation coefficient (ICC2.1) above 0.850 for all items. It was observed that outer loading of most items were more than the minimum acceptable value (0.7). Fornell-Larcker criterion demonstrate all values for each reflective construct was larger than the correlations with other constructs, indicating discriminant. The cross-loading values of each item has shown a weak correlation with all other constructs, except for the one to which it was theoretically associated.