Static foot posture associated with dynamic plantar pressure parameters.
METHODS
Controlled laboratory study.


OBJECTIVE
To explore potential associations between foot posture index (FPI-6) composite scores and dynamic plantar pressure measurements, and to describe each of the 6 subscales and the FPI-6 composite scores across our sample.


BACKGROUND
The FPI-6 is a static foot posture assessment comprised of 6 observations. Extreme scores have been associated with increased injury risk. However, knowledge describing the relationship between FPI-6 scores and plantar pressure distributions during gait is limited.


METHODS
Participants (n = 1000; 566 males, 434 females) were predominantly active adults (mean ± SD age, 30.6 ± 8.0 years; body mass index, 26.2 ± 3.7 kg/m²), who ran 3.1 ± 1.4 d/wk. Static and dynamic foot characteristics were compared using the FPI-6 and a capacitance-based pressure platform. Correlation and hierarchical stepwise regression analyses were performed to determine the most parsimonious set of dynamic pressure data associated with FPI-6 scores.


RESULTS
The mean ± SD FPI-6 score was 3.4 ± 2.9 (range, -6.0 to 11.0). Only 31 participants received a score of -2 (supinated foot) on any FPI-6 subscale. Classification of a pronated foot was 2.4 times more likely than a supinated foot. A 5-variable model (R = 0.57, R2 = 0.32) was developed to describe the association between dynamic plantar pressures and FPI-6 scores.


CONCLUSIONS
The multivariate model associated with FPI-6 scores comprised clinically plausible variables which inform the association between static and dynamic foot postures. Different cutoff values may be required when using the FPI-6 to screen for individuals with supinated feet, given the limited number of high-arched participants identified by FPI-6 classifications.
Teyhen
Deydre S
DS
Department of Physical Therapy, US Army Medical Department Center and School, 3150 Stanley Road, Fort Sam Houston, TX 78234, USA. deydre.teyhen@amedd.army.mil
Stoltenberg
Brian E
BE
Eckard
Timothy G
TG
Doyle
Peter M
PM
Boland
David M
DM
Feldtmann
Jess J
JJ
McPoil
Thomas G
TG
Christie
Douglas S
DS
Molloy
Joseph M
JM
Goffar
Stephen L
SL
D000328:Adult; D005260:Female; D005528:Foot / Q000502:physiology*; D006801:Humans; D008297:Male; D011187:Posture / Q000502:physiology*; D011312:Pressure; D011403:Pronation / Q000502:physiology; D012044:Regression Analysis; D013484:Supination / Q000502:physiology