Reliability of the modified Foot Posture Index.
BACKGROUND
The Foot Posture Index (FPI) has been advocated as a simple and convenient tool to assess static foot posture in a clinical setting. Although published studies have indicated that the FPI has good intrarater reliability and moderate interrater reliability, these studies were conducted on a previous version of the tool that used eight criteria to score a patient's foot posture. The revised tool has only six criteria (FPI-6). The purpose, therefore, of this study was to investigate the intrarater and interrater reliability of the revised version of the FPI.


METHODS
Three different raters used the FPI-6 to twice evaluate 92 feet from 46 individuals.


RESULTS
Intrarater reliability was high but interrater reliability was only moderate. In addition, using the raw score generated by the FPI-6 to classify feet into one of five categories did not improve agreement between raters.


CONCLUSIONS
The FPI-6 should be used with extreme caution and may actually have limited value, especially from a research perspective.
Cornwall
Mark W
MW
Department of Rehabilitation Sciences, Program in Physical Therapy, Northern Arizona University, Flagstaff, AZ 86011, USA.
McPoil
Thomas G
TG
Lebec
Michael
M
Vicenzino
Bill
B
Wilson
Jodi
J
D000328:Adult; D005260:Female; D005528:Foot / Q000502:physiology*; D006801:Humans; D008297:Male; D010808:Physical Examination / Q000379:methods*; D011403:Pronation / Q000502:physiology*; D015203:Reproducibility of Results; D013484:Supination / Q000502:physiology*