title: Two-dimensional coherence for measurement of asymmetry in postural steadiness.
abstract: Two-dimensional magnitude squared coherence (2D-MSC) is developed to compare the two-valued time series which represent the center of pressure (COP) under each foot. A sinusoidal multiple taper spectral estimator is used to reduce bias and improve spectral resolution. The measure is applied to evaluate symmetry in the dual-plate postural steadiness time series obtained from healthy young and elderly volunteers, and patients with Huntington's Disease (HD), a group in which asymmetries in postural steadiness are anticipated. The results demonstrate that the 2D-MSC is a robust measure of inter-limb coordination that may be of value in studies of aging and neurologic disease.
authors.affiliation: Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, FDA, United States. Joel.Myklebust@fda.hhs.gov
authors.forename: J B
authors.initials: JB
authors.lastname: Myklebust
authors.forename: E G
authors.initials: EG
authors.lastname: Lovett
authors.forename: B M
authors.initials: BM
authors.lastname: Myklebust
authors.forename: N
authors.initials: N
authors.lastname: Reynolds
authors.forename: L
authors.initials: L
authors.lastname: Milkowski
authors.forename: T E
authors.initials: TE
authors.lastname: Prieto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D005260:Female; D005528:Foot / Q000502:physiology; D005583:Fourier Analysis; D006801:Humans; D006816:Huntington Disease / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D011312:Pressure; D012815:Signal Processing, Computer-Assisted