Exploring the Relationship between Multi-Segment Foot Kinematics and Plantar Pressure Data in Adolescents with Planus and Cavus Foot Deformities: A Pilot Study

The medial longitudinal arch (MLA) plays a significant role in shock absorption and elasticity with respect to the motion of the foot. Pes planus (low MLA) and pes cavus (high MLA) are two deformities of the MLA commonly present in children with neurologic disabilities, which can contribute to abnormal walking patterns and the development of chronic foot pain long-term. It is often assumed that a change in MLA height equates with a change in medial or lateral plantar pressure. However, this relationship has not been sufficiently studied. The aim of this study was to investigate the relationship between MLA height and plantar pressure for specific regions of the foot to test the validity of this assumption. This study was accomplished by conducting a retrospective study using data gathered from the computerized gait analysis laboratory of a local rehabilitation hospital. By using a technique developed to integrate a multi-segment foot (MSF) model and plantar pressure data, the relationship between the severity of foot deformity and plantar pressure was examined; Spearman and Pearson coefficient values were calculated to determine the relationship between selected plantar pressure variables with respect to the mean stance MLA angle (MLAA); the relationship was considered statistically significant if the coefficient value was greater than .50 with a p-value of less than .05. More pes planus feet were found to have significantly higher impulse and contact area values in the plantar pressure of the medial midfoot region and more cavus feet were found to have higher mean pressure and impulse values in the plantar pressure of the lateral forefoot region. By measuring the MLAA from MSF kinematics interfaced with plantar pressure data, the magnitude of planus and cavus appears able to be assessed objectively, providing a useful way for tracking the progression of these common foot deformities over time