strong than the total FPI score and rearfoot
motion (r = 0.92), indicating the association
between frontal plane score and maximum
eversion angle is not as strong as the total
FPI score and maximum rearfoot eversion
angle. This was consistent with correlations
of frontal plane rearfoot FPI score and frontal
plane motion during gait within the pronated
and normal groups which were strong (r =
0.79, p < 0.05, pronated group, r = 0.71, p <
0.05 normal group), however, were less strong
than the relationship between the total FPI
and maximum rearfoot eversion (0.81, p <
0.05 and 0.76, p < 0.05 for the pronated and
normal groups respectively). Linear regression
analysis demonstrated a significant and strong
relationship between the total FPI score and
maximum rearfoot eversion (r2 = 0.85, p < 0.001)
for the entire subject cohort (n = 40). Therefore,
the total FPI score can be considered to be
highly predictive of maximum rearfoot eversion
angle across normal and pronated foot types.
Discussion
Correlations of the total FPI score and
maximum rearfoot eversion angle for both the
pronated and normal foot types demonstrated
a significant positive relationship (r = 0.81 and r
= 0.76 respectively). Linear regression analysis
suggests strong predictive capacity of the FPI
for frontal plane motion of the rearfoot (r2 =
0.85, p < 0.001) with the FPI predicting 85%
16
14
12
10
8
6
4
2
0
0
2
4
6
8
10
foot posture index score
Figure 3: Scatterplot maximum rearfoot eversion versus total FPI score, (r = 0.92,
p < 0.05, n = 40).
Current Pedorthics | May/June 2019
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