title: "Postural first" principle when balance is challenged in elderly people.
abstract: Human cognitive processing limits can lead to difficulties in performing two tasks simultaneously. This study aimed to evaluate the effect of cognitive load on both simple and complex postural tasks. Postural control was evaluated in 128 noninstitutionalized elderly people (mean age = 73.6 ± 5.6 years) using a force platform on a firm support in control condition (CC) and mental counting condition (MCC) with eyes open (EO) and eyes closed (EC). Then, the same tests were performed on a foam support. Sway path traveled and area covered by the center of foot pressure were recorded, low values indicating efficient balance. On firm support, sway path was higher in MCC than in CC both in EO and EC conditions (p < 0.001). On foam support, sway path was higher in CC than in MCC in EC condition (p < 0.001), area being higher in CC than in MCC both in EO (p < 0.05) and EC (p < 0.001) conditions. The results indicate that cognitive load alters balance control in a simple postural task (i.e. on firm support), which is highlighted by an increase of energetic expenditure (i.e. increase of the sway path covered) to balance. Awareness may not be increased and the attentional demand may be shared between balance and mental task. Conversely, cognitive load does not perturb the realization of a new complex postural task. This result showed that postural control is prioritized ("postural first" principle) when seriously challenged.
authors.affiliation: 1INSERM U 954, Nutrition-Génétique et Exposition aux Risques Environnementaux, Faculty of Medicine, Vandoeuvre-lès-Nancy, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Lion
authors.forename: Rosario S
authors.initials: RS
authors.lastname: Spada
authors.forename: Gilles
authors.initials: G
authors.lastname: Bosser
authors.forename: Gérome C
authors.initials: GC
authors.lastname: Gauchard
authors.forename: Guido
authors.initials: G
authors.lastname: Anello
authors.forename: Paolo
authors.initials: P
authors.lastname: Bosco
authors.forename: Santa
authors.initials: S
authors.lastname: Calabrese
authors.forename: Antonella
authors.initials: A
authors.lastname: Iero
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Stella
authors.forename: Maurizio
authors.initials: M
authors.lastname: Elia
authors.forename: Philippe P
authors.initials: PP
authors.lastname: Perrin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology* / Q000523:psychology; D003071:Cognition / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D004856:Postural Balance / Q000502:physiology*
keywords: aging; attention; cognition; postural control