Center of pressure based segment inertial parameters validation.

Clint Hansen,Philippe Gorce,Brice Isableu,Gentiane Venture,Nasser Rezzoug,Antoine Nordez

doi:10.1371/journal.pone.0180011

Abstract

By proposing efficient methods for estimating Body Segment Inertial Parameters’ (BSIP) estimation and validating them with a force plate, it is possible to improve the inverse dynamic computations that are necessary in multiple research areas. Until today a variety of studies have been conducted to improve BSIP estimation but to our knowledge a real validation has never been completely successful. In this paper, we propose a validation method using both kinematic and kinetic parameters (contact forces) gathered from optical motion capture system and a force plate respectively. To compare BSIPs, we used the measured contact forces (Force plate) as the ground truth, and reconstructed the displacements of the Center of Pressure (COP) using inverse dynamics from two different estimation techniques. Only minor differences were seen when comparing the estimated segment masses. Their influence on the COP computation however is large and the results show very distinguishable patterns of the COP movements. Improving BSIP techniques is crucial and deviation from the estimations can actually result in large errors. This method could be used as a tool to validate BSIP estimation techniques. An advantage of this approach is that it facilitates the comparison between BSIP estimation methods and more specifically it shows the accuracy of those parameters.

Highlights

Biomechanical and clinical human movement analyses contain a variety of measurements to evaluate the performance or the health status of subjects
The aim of the present study was to investigate the influence of two Body Segment Inertial Parameters’ (BSIP) estimation methods on the Center of Pressure (COP) movement during motions, using an optical motion capture system and a force plate
Compared to previous research [23,26] and to obtain a more thorough cross validation, we assessed the accuracy of BSIP identification by considering movements involving walking, running, overarm throwing and basketball throws

Summary

Introduction

Biomechanical and clinical human movement analyses contain a variety of measurements to evaluate the performance or the health status of subjects. Those measurements are based on mathematical and physical models that are applied to the human body. Body segment inertial parameters (BSIPs) (which are: mass, center of mass (COM), and inertia tensor) have been shown to be highly important for clinical and biomechanical research [1,2].

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Conclusion