Identification of Functional Ankle Instability

Original Editor - Carina Therese Magtibay

Top Contributors - Carina Therese Magtibay  

Objective[edit | edit source]

The Identification of Functional Ankle Instability (IdFAI) is a 10-item questionnaire specifically designed and developed to determine an individual’s ankle stability status.[1] It is intended to give both researchers and clinicians a simple and effective tool based on two functional ankle instability (FAI) instruments: the Cumberland Ankle Instability Test and the Ankle Instability Instrument .[2]

Intended Population[edit | edit source]

Individuals with lasting deficits following an ankle sprain are recommended to answer IdFAI. The sensation of the ankle "giving way" (reported in about 40-60% of individuals with a history of at least one ankle sprain[3][4]) in the absence of a mechanical deficit is usually an indication of having FAI.[1] IdFAI will detect whether individuals meet the minimum criteria necessary for inclusion in the functional ankle instability population[5].

Cross-cultural Adaptations[edit | edit source]

IdFAI has been studied and translated into different languages:

Method of Use[edit | edit source]

IdFAI is a simple patient-reported outcome measure with items grouped in three factors:[1]

  • Factor 1: History of ankle instability. These questions (Q5,Q6,Q7 and Q10) reflect the general sense of ankle instability. It includes items concerning feelings of instability during sports/recreational activities, the last time giving way episodes occurred, how often giving way occurs, and ability to stop ankle from continuing to roll over.
  • Factor 2: Initial ankle sprain. These questions (Q1,Q2,Q3,Q4) provide a better assessment of the severity of previous ankle sprains. It includes questions such as how many ankle sprains the individual sustained, time since last ankle sprain, time weightbearing assistance was needed, and grade of ankle sprain diagnosed by a healthcare provider.
  • Factor 3: Instability during activities of daily living. It includes questions (Q8,Q9) regarding length of time following an ankle sprain required for the ankle to return to normal, as well as question concerning instability during activities of daily living.

Scoring[edit | edit source]

  • Total score of 10 or lower = participant is unlikely to have FAI
  • Total score of 11 or higher =participant is likely to have FAI

Evidence[edit | edit source]

Reliability[edit | edit source]

Overall, IdFAI demonstrated excellent consistency. The values are as follows:[2]

Factor IdFAI test–retest reliability Remarks
overall ICC2,1 = 0.92 excellent
Factor 1 ICC2,1 = 0.81 good
Factor 2 ICC2,1 = 0.94 excellent
Factor 3 ICC2,1 = 0.83 good

Validity[edit | edit source]

There is a statistically significant correlation between Lower Extremity Functional Screen (LEFS) and the IdFAI which is noted on the table below:[2]

Factor Correlation Remarks
overall p = -0.38 moderate
Factor 1 p = -0.29 weak
Factor 2 p = -0.24 weak
Factor 3 p = -0.41 moderate
  • The correlation was negative because of the inverse relationship of IdFAI and LEFS. Low score on the LEFS indicates a high degree of lower extremity dysfunction while a high score on the IdFAI indicates higher degree of ankle instability. [2]
  • Moderate correlation can be attributed to the nature of the LEFS. The LEFS is not an ankle-specific instrument and focuses mainly on disability related to the lower limb during ADL.[2]

Links[edit | edit source]

IdFAI questionnaire

References[edit | edit source]

  1. 1.0 1.1 1.2 Simon J, Donahue M, Docherty C. Development of the identification of functional ankle instability (IdFAI). Foot & Ankle International. 2012 Sep;33(9):755-63.
  2. 2.0 2.1 2.2 2.3 2.4 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 Care. 2013 Jan 1;5(1):38-43.
  3. Gerber JP, Williams GN, Scoville CR, Arciero RA, Taylor DC. Persistent disability associated with ankle sprains: a prospective examination of an athletic population. Foot & ankle international. 1998 Oct;19(10):653-60.
  4. Cameron KL, Owens BD, DeBerardino TM. Incidence of ankle sprains among active-duty members of the United States Armed Services from 1998 through 2006. Journal of athletic training. 2010 Jan;45(1):29-38.
  5. Donahue M, Simon J, Docherty CL. Critical review of self-reported functional ankle instability measures. Foot & Ankle International. 2011 Dec;32(12):1140-6.
  6. Martinez BR, Sauers AD, Ferreira CL, de Castro Lugli L, Turchetto PC, Docherty CL, Yi LC. Translation, cross-cultural adaptation, and measurement properties of the Brazilian version of the Identification of Functional Ankle Instability (IdFAI) questionnaire. Physical Therapy in Sport. 2018 Jan 1;29:1-8.
  7. Wang W, Sheng J, Tang Y, Xie Q, Wei M, Li Z, Zheng W. Adaptation and psychometric evaluation of the simplified Chinese version of the identification of functional ankle instability questionnaire in Chinese-speaking patients with chronic ankle instability disorders. BMC Musculoskeletal Disorders. 2020 Dec;21(1):1-1.
  8. Beaudart C, Demoulin C, Mehmeti K, Bornheim S, Van Beveren J, Kaux JF. Validity and reliability of the French translation of the Identification of Functional Ankle Instability (IdFAI). Foot and Ankle Surgery. 2022 Aug 1;28(6):756-62.
  9. Tsekoura M, Billis E, Samada EK, Savvidou I, Fousekis K, Xergia S, Lampropoulou S, Tsepis E. Cross cultural adaptation, reliability and validity of the Greek version of Identification of Functional Ankle Instability (IdFAI) questionnaire. Foot and Ankle Surgery. 2021 Dec 1;27(8):906-10.
  10. Mineta S, Inami T, Fukano M, Hoshiba T, Masuda Y, Yoshimura A, Kumai T, Hirose N. The reliability, and discriminative ability of the identification of functional ankle instability questionnaire, Japanese version. Physical Therapy in Sport. 2019 Jan 1;35:1-6.
  11. Ko J, Rosen AB, Brown CN. Cross-cultural adaptation, reliability, and validation of the Korean version of the identification functional ankle instability (IdFAI). Disability and Rehabilitation. 2018 Dec 18;40(26):3185-90.
  12. Mohamadi S, Dadgoo M, Ebrahimi I, Salavati M, Saeedi A, Valiollahi B. Translation, cross-cultural adaptation, reliability, and validity of the Identification of Functional Ankle Instability questionnaire in Persian speaking participants with a history of ankle sprain. Disability and rehabilitation. 2019 Jul 31;41(16):1931-6.
  13. Cervera-Garvi P, Ortega-Avila AB, Marchena-Rodriguez A, Gijon-Nogueron G. Transcultural adaptation and validation of the Spanish version of the Identification of Functional Ankle Instability questionnaire (IdFAI-Sp). Disability and Rehabilitation. 2022 Jun 19;44(13):3221-7.
  14. Tayfur A, Şendil A, Karakaya J, Ergun N. Cross-cultural adaptation, validity, and reliability of Turkish version of Identification of Functional Ankle Instability (IdFAI) scale. Acta orthopaedica et traumatologica turcica. 2020 May;54(3):300.