From: Normative values for the Foot Posture Index
Pathological
Potentially
abnormal
Normal range
< -2 SD
-2 SD
-1 SD
Mean
+1 SD
+2 SD
> +2 SD
FPI
logit
-2.2
+0.1
+2.4
+4.7
+7.0
FPI raw
score
< -3
-3
+1
+4
+7
+10
> +10