title: Aging causes a reorganization of cortical and spinal control of posture.
abstract: Classical studies in animal preparations suggest a strong role for spinal control of posture. In humans it is now established that the cerebral cortex contributes to postural control of unperturbed and perturbed standing. The age-related degeneration and accompanying functional changes in the brain, reported so far mainly in conjunction with simple manual motor tasks, may also affect the mechanisms that control complex motor tasks involving posture. This review outlines the age-related structural and functional changes at spinal and cortical levels and provides a mechanistic analysis of how such changes may be linked to the behaviorally manifest postural deficits in old adults. The emerging picture is that the age-related reorganization in motor control during voluntary tasks, characterized by differential modulation of spinal reflexes, greater cortical activation and cortical disinhibition, is also present during postural tasks. We discuss the possibility that this reorganization underlies the increased coactivation and dual task interference reported in elderly. Finally, we propose a model for future studies to unravel the structure-function-behavior relations in postural control and aging.
authors.affiliation: Center for Human Movement Sciences, University of Groningen, University Medical Center Groningen Groningen, Netherlands.
authors.forename: Selma
authors.initials: S
authors.lastname: Papegaaij
authors.affiliation: Movement and Sports Science, Department of Medicine, University of Fribourg Fribourg, Switzerland.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Taube
authors.affiliation: Laboratory of Applied Biology, Faculty for Motor Sciences, Université Libre de Bruxelles Brussels, Belgium.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Baudry
authors.affiliation: Center for Human Movement Sciences, University of Groningen, University Medical Center Groningen Groningen, Netherlands.
authors.forename: Egbert
authors.initials: E
authors.lastname: Otten
authors.affiliation: Center for Human Movement Sciences, University of Groningen, University Medical Center Groningen Groningen, Netherlands ; Faculty of Health and Life Sciences, Northumbria University Newcastle Upon Tyne, UK.
authors.forename: Tibor
authors.initials: T
authors.lastname: Hortobágyi
keywords: TMS; aging; cerebral cortex; fMRI; neuroplasticity; postural control