New Test of Foot Posture Revised
The authors of this report have been working on a way to quickly and easily measure foot posture. The first tool called the Foot Posture Index (FPI-8) had eight test items. It was tested and found valid and reliable. The FPI-8 was even used in several studies of athletes and orthotics.

But further research showed that two of the eight items in the test appeared to be measuring something else. These two tests didn't measure overall foot posture and were more likely a measure of foot shape or size.

In this study, the authors dropped the two misfit items and retested two groups using the FPI-6. The first group had a known foot problem associated with a condition called Charcot-Marie-Tooth disease. The second group had normal, healthy adults ages 18 to 65 years.

Analysis of the results confirmed that the FPI-6 is a good measure of foot posture. It can be used to assess a wide range of foot postures. The finalized FPI-6 should be tested again with a larger group. Normal values must be established.
References
Anne-Maree Keenan, MAppSc, et al. The Foot Posture Index: Rasch Analysis of a Novel, Foot-Specific Outcome Measure. In Archives of Physical Medicine and Research. January 2007. Vol. 88. No. 1. Pp. 88-93.