title: Cross-cultural adaptation and reliability of the Italian version of the Foot Function Index (FFI-I) for patients with plantar fasciitis.
abstract: OBJECTIVE
  The aim of this paper was to translate and cross-culturally adapt the FFI to the Italian language, and to assess the reliability of the Italian version of the FFI (FFI-I) for plantar fasciitis.
  
  
  METHODS
  Fifty symptomatic patients affected by plantar fasciitis completed the FFI-I scale twice, at interval of one week. The translation of the FFI was performed according to international standards for translation of questionnaires. Test-retest reliability was evaluated using intraclass correlation coefficient (ICC). Internal consistency was measured by Cronbach α coefficient. Ceiling and floor effects were assessed.
  
  
  RESULTS
  The process resulted in an intelligible version of the questionnaire. The reliability of the FFI-I was adequate, with an ICC ranging from 0.86 to 0.98 for test-retest reliability. The FFI-I showed an excellent internal consistency, ranging from 0.93 to 0.99 for all subscales. Three items involving disability and four items involving activities restrictions had highest proportion of floor score.
  
  
  CONCLUSIONS
  The FFI-I is a reliable and valid instrument to assess clinical severity in patients with plantar fasciitis and it is suitable for daily practice. We suggest evaluating the total FFI-I score along with the distinct scores of the three subscales of the FFI-I in order to interpret more correctly minor changes in patient status during repetitive outcome assessments.
authors.affiliation: Physical Medicine and Rehabilitation Unit Sant'Andrea Hospital "La Sapienza" University of Rome, Rome, Italy - mariovetrano@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Vetrano
authors.forename: M C
authors.initials: MC
authors.lastname: Vulpiani
authors.forename: D
authors.initials: D
authors.lastname: Erroi
authors.forename: A
authors.initials: A
authors.lastname: Vadalà
authors.forename: A
authors.initials: A
authors.lastname: Ferretti
authors.forename: V M
authors.initials: VM
authors.lastname: Saraceni
mesh_terms: D003431:Cross-Cultural Comparison; D036981:Fasciitis, Plantar / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014177:Translations