Article

The aim of this study was the fine tuning of a Kalman filter with the intent to
provide optimal estimates of lower trunk orientation in the frontal and sagittal
planes during treadmill walking at different speeds using measured linear
acceleration and angular velocity components represented in a local system of
reference. Data were simultaneously collected using both an inertial measurement
unit (IMU) and a stereophotogrammetric system from three healthy subjects walking
on a treadmill at natural, slow and fast speeds. These data were used to estimate
the parameters of the Kalman filter that minimized the difference between the
trunk orientations provided by the filter and those obtained through
stereophotogrammetry. The optimized parameters were then used to process the data
collected from a further 15 healthy subjects of both genders and different
anthropometry performing the same walking tasks with the aim of determining the
robustness of the filter set up. The filter proved to be very robust. The root
mean square values of the differences between the angles estimated through the
IMU and through stereophotogrammetry were lower than 1.0 degrees and the
correlation coefficients between the corresponding curves were greater than 0.91.
The proposed filter design can be used to reliably estimate trunk lateral and
frontal bending during walking from inertial sensor data. Further studies are
needed to determine the filter parameters that are most suitable for other motor
tasks.
CI - Copyright (c) 2011. Published by Elsevier B.V.

Langue : ANGLAIS