Cross Cultural Adaptation and validation of the Hindi Version of Foot Function Index

Abstract Background The Foot Function Index is a reliable and widely used self-administered index that measures the impact of foot pathology on function. The rising incidence of foot disorders emphasizes the importance of culturally adapted, relevant, and accurate language-specific outcome tools. With 571 million Hindi-speaking people living globally, until now no validated Hindi version of FFI is available. We aimed to translate, cross-cultural adapt, and psychometrically test the FFI-Hindi version for use in Hindi-speaking individuals with foot conditions. Methods The translation of NDI-Hi was performed according to guidelines given by MAPI Research Trust. A total of 223 Hindi-speaking participants afflicted with foot conditions completed the FFI-Hi alongside the Short Form 36 (SF-36) questionnaire. The initial phase was the translation and adaptation of FFI to cultural context. Followed by testing of psychometric properties with a subset of 133 participants reiterating the FFI-Hi after a 7-day interval. Results The mean age of the participants was 47.10 years. Majority of the participants were male (66.4%) and the most common foot condition was plantar fasciopathy (40.8%). The mean score of FF-Hi was 33.7 ± 11.7. The internal consistency of FFI-Hi was good with the Cronbach’s alpha (α) value of 0.891 and excellent reproducibility with the intra-class correlation of 0.90. The responsiveness of the tool was estimated using 95% minimal detectable change (MCD) and the standard error of measurement of the FFI-Hi was 22.02 and 7.94 respectively. Convergent validity was upheld by moderate correlations observed between FFI-Hi subscales and SF-36 domains. Factor analysis corroborated the multidimensional nature of the FFI-Hi. Conclusion The FFI-Hindi version demonstrated acceptable psychometric properties facilitating the inclusion of the FFI-Hindi version into clinical practice and research. Further, the context-specific Hindi language version of FFI will enhance the utility of FFI in foot function evaluation and remove language barrier in patients reporting disability and activity limitation related to foot conditions. Registration:Clinical Trials Registry of India (CTRI/2023/07/055734)