title: Circular components in center of pressure signals.
abstract: Static posturography provides an objective assessment of postural control by characterizing the body sway during upright standing. The center of pressure (COP) signal is recorded by a force platform, and it is analyzed by means of many different models and techniques. Most of the parameters calculated according to these different approaches are affected by relevant intra- and intersubject variability or do not have a clear physiological interpretation. Traditional approaches decompose the COP signal into anteroposterior and mediolateral time series, corresponding to ankle plantar/dorsiflexion and hip adduction/abduction, respectively. In this study we hypothesized that COP signals show inherent rotational characteristics. To verify our hypothesis we applied the rotary spectra analysis to the two-dimensional COP signal to decompose it into clockwise and counterclockwise rotational components. We demonstrated the presence of rotational components in the COP signal of healthy subjects, providing a reference data set of the spectral characteristics of these components.
authors.affiliation: Dept. of Electronics and Telecommunications, Politecnico di Torino, Torino, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Agostini
authors.forename: Emma
authors.initials: E
authors.lastname: Chiaramello
authors.forename: Marco
authors.initials: M
authors.lastname: Knaflitz
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D005528:Foot / Q000502:physiology; D006801:Humans; D008297:Male; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011312:Pressure; D012399:Rotation; D019415:Torque; D055815:Young Adult