title: A wearable ground reaction force sensor system and its application to the measurement of extrinsic gait variability.
abstract: Wearable sensors for gait analysis are attracting wide interest. In this paper, a wearable ground reaction force (GRF) sensor system and its application to measure extrinsic gait variability are presented. To validate the GRF and centre of pressure (CoP) measurements of the sensor system and examine the effectiveness of the proposed method for gait analysis, we conducted an experimental study on seven volunteer subjects. Based on the assessment of the influence of the sensor system on natural gait, we found that no significant differences were found for almost all measured gait parameters (p-values < 0.05). As for measurement accuracy, the root mean square (RMS) differences for the two transverse components and the vertical component of the GRF were 7.2% ± 0.8% and 9.0% ± 1% of the maximum of each transverse component and 1.5% ± 0.9% of the maximum vertical component of GRF, respectively. The RMS distance between both CoP measurements was 1.4% ± 0.2% of the length of the shoe. The area of CoP distribution on the foot-plate and the average coefficient of variation of the triaxial GRF, are the introduced parameters for analysing extrinsic gait variability. Based on a statistical analysis of the results of the tests with subjects wearing the sensor system, we found that the proposed parameters changed according to walking speed and turning (p-values < 0.05).
authors.affiliation: Department of Intelligent Mechanical Systems Engineering, Kochi University of Technology, 185 Miyanokuchi, Tosayamada-Cho, Kami-City, Kochi 782-8502, Japan. liu.tao@kochi-tech.ac.jp
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Inoue
authors.forename: Kyoko
authors.initials: K
authors.lastname: Shibata
mesh_terms: D001696:Biomechanical Phenomena; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D005684:Gait / Q000502:physiology*; D006801:Humans; D013314:Stress, Mechanical