Integration of foot pressure and foot kinematics measurements for medical applications

Abstract

Plantar pressure measurement quantitatively characterizes the interaction between the foot and the ground. Clinical assessment of foot function often relies on the analysis of pressure and pressure-related parameters under specific regions of the foot. Identification of these foot regions is a crucial and yet highly debated issue. Algorithms to identify these regions are mostly based on generic, geometrical features of the acquired pressure map. But this approach may not be valid in the presence of foot deformity. Three-dimensional motion tracking can deliver accurate and reliable quantification of full-body motion through all anatomical planes and axes of human movement. When used in conjunction with validated multi-segment foot models, clinicians are able to investigate detailed relative motion of the foot and ankle complex. The integration of these two measurement techniques offers a new perspective in the study of foot function. First, it allows anatomical, as opposed to purely geometrical, masking of dynamic pressure footprints. This leads to a reliableassociation of footprint regions with foot anatomy, even in the presence of significant foot deformity and abnormal footprint shapes. Second, but equally important, it allows joint kinematics of foot segments to be correlated with corresponding regional loads. A method for this integration was first proposed in the early 2000s, and since then it has been implemented in numerous studies. State-of-the-art instrumentation and validated foot models are necessary to implement this methodology. An overview of the integration technique, applicability, validation, and initial clinical applications is hereby reviewed and discussed.