Translation, validity, and reliability of the Foot Posture Index (FPI-6) - Turkish version.

PURPOSE

The aim of this study was to translate the English version of the Foot Posture Index (FPI-6) into Turkish and to examine its psychometric properties.

METHODS

After the forward-backward translation process, the internal consistency and intra - and inter-rater reliability were evaluated by using Cronbach's α and Intraclass Correlation Coefficient (ICC) (two-way random effects model with absolute agreement type), respectively. The agreement between reliability assessments was investigated by the standard error of measurement (SEM) and the minimal detectable change (MDC). Criterion validity was assessed in relationship between the Turkish FPI-6 and Foot Function Index (FFI) and the American Orthopedic Foot and Ankle Society (AOFAS).

RESULTS

The study was completed with 45 patients with foot/ankle problems. The internal consistency (Cronbach's α = 0.85; 0.78, respectively), intra-reliability (ICC = 0.96; 0.94, respectively), and inter-reliability (ICC = 0.93; both of them) of the Turkish version of the FPI-6 were excellent for the dominant and non-dominant lower limb. The SEM was low, and the agreement was considered to have high absolute reliability, as demonstrated by the smallest change in measurement error. The Turkish FPI-6 also had moderate correlations with the FFI and AOFAS ( < .05).

CONCLUSIONS

It has been proven that the Turkish FPI-6 is valid and reliable and can be used by Turkish-speaking researchers and clinicians in patients with various foot-ankle problems.