Upper Limb Kinematics Using Inertial and Magnetic Sensors: Comparison of Sensor-to-Segment Calibrations.
Magneto-Inertial Measurement Unit sensors (MIMU) display high potential for the quantitative evaluation of upper limb kinematics, as they allow monitoring ambulatory measurements. The sensor-to-segment calibration step, consisting of establishing the relation between MIMU sensors and human segments, plays an important role in the global accuracy of joint angles. The aim of this study was to compare sensor-to-segment calibrations for the MIMU-based estimation of wrist, elbow, and shoulder joint angles, by examining trueness ("close to the reference") and precision (reproducibility) validity criteria. Ten subjects performed five sessions with three different operators. Three classes of calibrations were studied: segment axes equal to technical MIMU axes (TECH), segment axes generated during a static pose (STATIC), and those generated during functional movements (FUNCT). The calibrations were compared during the maximal uniaxial movements of each joint, plus an extra multi-joint movement. Generally, joint angles presented good trueness and very good precision in the range 5°-10°. Only small discrepancy between calibrations was highlighted, with the exception of a few cases. The very good overall accuracy (trueness and precision) of MIMU-based joint angle data seems to be more dependent on the level of rigor of the experimental procedure (operator training) than on the choice of calibration itself.
Institut National de Recherche et de Sécurité (INRS), 54519 Vandoeuvre-lès-Nancy, France. bricebouvier.fr@gmail.com.|Université de Lyon, F-69622 Lyon, France. bricebouvier.fr@gmail.com.|Université Claude Bernard Lyon 1, Villeurbanne, France. bricebouvier.fr@gmail.com.|IFSTTAR, UMR_T9406, LBMC Laboratoire de Biomécanique et Mécanique des Chocs, F69675 Bron, France. bricebouvier.fr@gmail.com.
Brice
B
Bouvier
Université de Lyon, F-69622 Lyon, France. sonia.duprey@univ-lyon1.fr.|Université Claude Bernard Lyon 1, Villeurbanne, France. sonia.duprey@univ-lyon1.fr.|IFSTTAR, UMR_T9406, LBMC Laboratoire de Biomécanique et Mécanique des Chocs, F69675 Bron, France. sonia.duprey@univ-lyon1.fr.
Sonia
S
Duprey
Institut National de Recherche et de Sécurité (INRS), 54519 Vandoeuvre-lès-Nancy, France. laurent.claudon@inrs.fr.
Laurent
L
Claudon
Université de Lyon, F-69622 Lyon, France. raphael.dumas@ifsttar.fr.|Université Claude Bernard Lyon 1, Villeurbanne, France. raphael.dumas@ifsttar.fr.|IFSTTAR, UMR_T9406, LBMC Laboratoire de Biomécanique et Mécanique des Chocs, F69675 Bron, France. raphael.dumas@ifsttar.fr.
Raphaël
R
Dumas
Institut National de Recherche et de Sécurité (INRS), 54519 Vandoeuvre-lès-Nancy, France. adriana.savescu@inrs.fr.
Adriana
A
Savescu
D000328:Adult; D001696:Biomechanical Phenomena; D002138:Calibration; D006801:Humans; D007596:Joints / Q000502:physiology; D008280:Magnetics / Q000295:instrumentation*; D008297:Male; D011187:Posture / Q000502:physiology; D034941:Upper Extremity / Q000502:physiology*
accuracy; ambulatory system; joint angle; magneto-inertial measurement unit sensors; sensor-to-segment calibration