Correlation between static foot type measurements and clinical assessments

An accurate and consistent differentiation of foot type is needed to assess appropriate treatments and to examine potential risk factors for acute and overuse injuries.

One hundred forty-seven members of the American Orthopaedic Foot and Ankle Society were asked to complete a questionnaire related to clinical assessments of foot type and to examine 30 photographs of healthy feet taken on the mirrored foot photo box (MFPB). Responders were asked to categorize each image into one of five categories (pes planus, low arch, normal, high arch, and pes cavus). Different static measurements were obtained from each image. Pearson correlations were calculated between the static foot measures and the clinical grade. Significantly correlated parameters were analyzed via regression analysis.

Clinical assessment was reported to be the most important tool in defining foot type (69.9%) followed by standing radiographs and foot print measurements. Clinicians stated that arch height (56.2%) was the most used physical characteristic, while the lateral talo-first metatarsal angle (64.4%) was the most used radiographic assessment. Foot measurements were correlated with the clinical grade (r = 0.511 to 0.780). Regression analysis revealed that rearfoot angle, foot print index and truncated arch index were significant predictors of clinically defined foot type. Rearfoot angle accounted for 78% of the variance in clinically assessed foot type.

The results of this study indicate the need to measure multiple parameters to assess foot type. However, if only one parameter can be collected, it appears that rearfoot angle explains the majority of variance in the clinically assessed foot type.