Background: Although extreme values of arch height have been associated with increased risk for overuse injury, knowledge is limited regarding the association between arch height and plantar pressure distributions during gait. The primary purpose of this study was to explore which plantar pressure measurements during gait were associated with static arch height and arch height index.
Methods: Static arch height, arch height index, and dynamic plantar pressure distributions were collected for 1000 subjects (566 males, 434 females, 30.6 [SD 8.0] years, 171.1 [SD 9.3]cm, 76.9 [SD 14.7]kg). A hierarchical regression analysis was performed to determine the most parsimonious set of plantar pressure parameters associated with arch height. The predicted values were used to calculate dynamic arch height index. Correlation and residual analysis were performed to assess the association between statically and dynamically determined arch height indices.
Findings: A 5-variable model (F = 296.6; P < 0.001) was able to describe the relationship between static arch height and the dynamic foot during gait (R =0 .77 [95% CI = 0.75-0.80]). The correlation between the static and dynamically determined arch height indices was r = 0.60 (95% CI = 0.53, 0.63), with a mean residual of 0.000 (SD 0.015).
Interpretation: A multivariate model generated by plantar parameters during gait was able to predict 60% of the variability in static arch height. This model consisted of variables that appear to be clinically plausible and inform the association between static arch height and dynamic foot posture. Future researchers should address the association between statically and dynamically determined AHI values with lower extremity overuse injuries.