title: Frailty assessment based on wavelet analysis during quiet standing balance test.
abstract: BACKGROUND
  A standard phenotype of frailty was independently associated with an increased risk of adverse outcomes including comorbidity, disability and with increased risks of subsequent falls and fractures. Postural control deficit measurement during quiet standing has been often used to assess balance and fall risk in elderly frail population. Real time human motion tracking is an accurate, inexpensive and portable system to obtain kinematic and kinetic measurements. The aim of this study was to examine orientation and acceleration signals from a tri-axial inertial magnetic sensor during quiet standing balance tests using the wavelet transform in a frail, a prefail and a healthy population.
  
  
  METHODS
  Fourteen subjects from a frail population (79±4 years), eighteen subjects from a prefrail population (80±3 years) and twenty four subjects from a healthy population (40±3 years) volunteered to participate in this study. All signals were analyzed using time-frequency information based on wavelet decomposition and principal component analysis.
  
  
  RESULTS
  The absolute sum of the coefficients of the wavelet details corresponding to the high frequencies component of orientation and acceleration signals were associated with frail syndrome.
  
  
  CONCLUSIONS
  These parameters could be of great interest in clinical settings and improved rehabilitation therapies and in methods for identifying elderly population with frail syndrome.
authors: Mathematics Department, Public University of Navarra, Pamplona, Spain.
authors: A
authors: A
authors: Martínez-Ramírez
authors: P
authors: P
authors: Lecumberri
authors: M
authors: M
authors: Gómez
authors: L
authors: L
authors: Rodriguez-Mañas
authors: F J
authors: FJ
authors: García
authors: M
authors: M
authors: Izquierdo
mesh_terms: D000054:Acceleration; D000058:Accidental Falls / Q000517:prevention & control; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001827:Body Height; D015992:Body Mass Index; D015897:Comorbidity; D005260:Female; D005583:Fourier Analysis; D016330:Frail Elderly; D006801:Humans; D008297:Male; D009038:Motion; D010641:Phenotype; D004856:Postural Balance; D025341:Principal Component Analysis; D015203:Reproducibility of Results