Ankle sprains are among the most frequent musculoskeletal injuries in daily life and sports. The recurrence index may reach up to 80% in athletes, due to residual symptoms that characterize a chronic
ankle sprain. The IdFAI(1) has been developed because up to now there was no reference measure or universally accepted definition of functional ankle instability. It has been the only questionnaire
able to determine the presence of functional ankle instability and is a valid instrument, reliable and developed in English. The aim of the study was translate and culturally adapt IdFAI questionnaire
to Brazilian Portuguese language; even analyze the validity, reliability and responsiveness.
Translation and cultural adaptation of IdFAI to Brazilian-Portuguese version process, was accomplished using standard guidelines and was applied in 50 university students. The reliability and
validation of IdFAI was tested in 100 lower limbs. The reliability was tested thru the reproducibility evaluation (test-retest inter and intra-observer), internal consistency, standard error of
measurement and minimal detectable change. The validation was made using the Portuguese version of Visual Analogic Scale to instability (VAS-I), Cumberland Ankle Instability Tool Questionnaire (CAIT)
and Lower Extremity Functional Scale (LEFS). Correlation among IdFAI and VAS-I, CAIT and LEFS was analysed by Spearman’s Correlation Coefficient. For responsiveness measurement, 12 assessments were
used before and after an eight week treatment period in 25 patients with functional ankle instability. Responsiveness was tested with the effect size and effects of “floor and ceiling”.
The Brazilian Portuguese IdFAI version showed high internal consistency (Cronbach α= 0.90), excellent reproducibility (intraclass correlation coefficient = 0.98 for inter and 0.96 for intra-observer);
and excellent agreement (standard error of measurement, 0.94 and 1.46 points for inter and intra-observer; minimal detectable change at the 90% confidence level, 2.20 points for inter and 3.40 for
intra-observer). IdFAI-Brasil version showed a strong correlation (r= 0.74 and -0.78; p< 0.001) with specific tools that measure ankle instability VAS-I and CAIT, and poor correlation (r=-0.21;
p=0.03) with LEFS scale. There was high responsiveness, with an effect size of 1.34 for patients receiving physical therapy intervention, and no floor or ceiling effects were detected for the IdFAI
The Brazilian version of the IdFAI questionnaire has shown to be a valid, reliable and responsive tool to evaluate ankle functional instability and it may be used in clinical and scientific fields.
1. Donahue M, Simon J, Docherty CL. Reliability and validity of a new questionnaire created to establish the presence of functional ankle instability: the IdFAI. Athletic Training & Sports Health
The authors thank the Coordination of Improvement of Higher Level Staff (CAPES), for the financial support that enabled the development of this study.