Cross‐cultural adaptation and validation of the Arabic version of the foot function index in patients with chronic lateral ankle instability

Abstract Background The English version of the Foot Function Index (FFI) is a reliable and valid tool for measuring pain and functional instability due to chronic lateral ankle instability (CLAI). However, its use among Arabic speakers with CLAI is limited because of the unavailability of the Arabic version of the FFI (FFI‐Arb). This study aimed to translate, cross‐culturally adapt and validate the FFI from the original English version into Arabic. Methods The FFI questionnaire was translated using the Beaton guidelines. Two‐hundred‐and‐thirty native Arabic‐speaking participants with CLAI were recruited from different physiotherapy clinics in Saudi Arabia. The convergent validity of the FFI‐Arb was tested using the Spearman correlation with the Arabic version Cumberland ankle instability tool (CAIT‐Arab). Test‐retest reliability was tested among 92 participants who completed the form again after seven days. Results Two‐hundred‐and‐thirty participants were enrolled (mean age = 32.09, Standard deviation (SD) = 8.64 years old). There was excellent internal consistency for the three subscales of FFI: pain (0.95), disability (0.97), and activity limitation (0.86), as for the total score (0.98). Convergent validity was analyzed by Spearman rank correlation between the new translated versions of FFI‐Arb and CAIT‐Arab. The total FFI‐Arb and CAIT‐Arab scores were moderately correlated (rho = − 0.569; p