title: Frailty assessment based on trunk kinematic parameters during walking.
abstract: BACKGROUND
  Physical frailty has become the center of attention of basic, clinical and demographic research due to its incidence level and gravity of adverse outcomes with age. Frailty syndrome is estimated to affect 20 % of the population older than 75 years. Thus, one of the greatest current challenges in this field is to identify parameters that can discriminate between vulnerable and robust subjects. Gait analysis has been widely used to predict frailty. The aim of the present study was to investigate whether a collection of parameters extracted from the trunk acceleration signals could provide additional accurate information about frailty syndrome.
  
  
  METHODS
  A total of 718 subjects from an elderly population (319 males, 399 females; age: 75.4 ± 6.1 years, mass: 71.8 ± 12.4 kg, height: 158 ± 6 cm) volunteered to participate in this study. The subjects completed a 3-m walk test at their own gait velocity. Kinematic data were acquired from a tri-axial inertial orientation tracker.
  
  
  RESULTS
  The spatio-temporal and frequency parameters measured in this study with an inertial sensor are related to gait disorders and showed significant differences among groups (frail, pre-frail and robust). A selection of those parameters improves frailty classification obtained to gait velocity, compared to classification model based on gait velocity solely.
  
  
  CONCLUSIONS
  Gait parameters simultaneously used with gait velocity are able to provide useful information for a more accurate frailty classification. Moreover, this technique could improve the early detection of pre-frail status, allowing clinicians to perform measurements outside of a laboratory environment with the potential to prescribe a treatment for reversing their physical decline.
authors.affiliation: Mathematics Department, Public University of Navarra, Campus de Arrosadía, 31006, Pamplona, Navarra, Spain. alicia.martinez@unavarra.es.
authors.forename: Alicia
authors.initials: A
authors.lastname: Martínez-Ramírez
authors.affiliation: Mathematics Department, Public University of Navarra, Campus de Arrosadía, 31006, Pamplona, Navarra, Spain. jon.martinikorena@gmail.com.
authors.forename: Ion
authors.initials: I
authors.lastname: Martinikorena
authors.affiliation: Mathematics Department, Public University of Navarra, Campus de Arrosadía, 31006, Pamplona, Navarra, Spain. marisol@unavarra.es.
authors.forename: Marisol
authors.initials: M
authors.lastname: Gómez
authors.affiliation: Mathematics Department, Public University of Navarra, Campus de Arrosadía, 31006, Pamplona, Navarra, Spain. pablo.lecumberri@unavarra.es.
authors.forename: Pablo
authors.initials: P
authors.lastname: Lecumberri
authors.affiliation: Mathematics Department, Public University of Navarra, Campus de Arrosadía, 31006, Pamplona, Navarra, Spain. nora.millor@gmail.com.
authors.forename: Nora
authors.initials: N
authors.lastname: Millor
authors.affiliation: Division of Geriatric Medicine, University Hospital of Getafe, Madrid, Spain. lrodriguez.hugf@salud.madrid.org.
authors.forename: Leocadio
authors.initials: L
authors.lastname: Rodríguez-Mañas
authors.affiliation: Division of Geriatric Medicine, Hospital Virgen del Valle, Complejo Hospitalario de Toledo, Toledo, Spain. franjogarcia@telefonica.net.
authors.forename: Francisco José
authors.initials: FJ
authors.lastname: García García
authors.affiliation: Department of Health Sciences, Public University of Navarra, Pamplona, Navarra, 31008, Spain. mikel.izquierdo@gmail.com.
authors.forename: Mikel
authors.initials: M
authors.lastname: Izquierdo
mesh_terms: D061725:Accelerometry / Q000379:methods*; D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D016330:Frail Elderly; D005684:Gait / Q000502:physiology; D006801:Humans; D008297:Male; D060726:Torso; D016138:Walking / Q000502:physiology*