Relationships between Foot Type and Dynamic Rearfoot Frontal Plane Motion
Kintrak 6.3, (The University of Calgary, Calgary,
Canada) to obtain joint angular displacement of
the rearfoot relative to the shank. Trials were
normalized to 120% of stance (including 20%
prior to heel strike) and kinematic data were
then processed using a MatLab program (The
Maths Works Inc., MA) to determine the discrete
variable (maximum eversion) to be entered
into the statistical analysis. Figure 2 (next page)
demonstrates a typical rearfoot frontal plane
motion time series output.
subject. Kinematic data were collected at 120
Hz.
Participants were required to perform barefoot
walking trials. A reference trial with the subject
standing in the anatomical position at natural
angle and base of gait was taken prior to the
walking trials. The participants were instructed
to walk through the capture area. Walking
trials were collected at a speed of 1.4 m/s. Trials
falling more than 10% outside these velocities
were excluded. A minimum of five acceptable
walking trials were performed by each subject
as this has been shown to provide consistent
kinematic data [13] . Kinematic data were low pass
filtered at 6 Hz using a zero phase second order
Butterworth filter. Three-dimensional marker
position coordinates were processed using
Statistical Analysis
Ordinal FPI data were converted to Rasch
transformed scores allowing the data to be
analyzed as interval data [14] . Linear correlations
were performed to identify the strength of
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-4
-6
% gait cycle
Figure 2: Walking gait frontal plane rearfoot motion mean (N = 1, FPI Score +6)
with 95% confidence intervals.
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