Effect of Load Change on Foot Arch in Different Positions Assessment of Foot Arch Using a Motion Analysis System and a Caliper - Goniometer System

[Purpose] The purpose of this study was to analyze the effect of load change on the foot arch in different foot positions using a Vicon motion analysis system and clinical assessment using a goniometer and calipers. The reliabilities of the measurements taken by the Vicon motion analysis system and clinical assessment were analyzed. [Subjects and Methods] The study (24.8 +/- 2.1 years). Two methods were used to measure the foot arch: (1) Vicon motion analysis and (2) a goniometer and calipers. Measurements were taken bilaterally in six different positions: standing on both feet, standing on one leg, cuff raise, medial weight shift, lateral weight shift, and toe dorsiflexion. [Results] The heights of the medial longitudinal, lateral longitudinal, and transverse arches in dynamic positions were significantly greater than that in the static standing position. The results of the Vicon motion analysis system correlated highly with those of measurements obtained via clinical assessment only in the static position. [Conclusion] When the foot and ankle joints were in dynamic and unstable positions, the arches were higher than those in the static position because of the windlass mechanism. Simultaneous assessment of all three foot arches in various positions is needed for effective evaluation.