Central organization in the generation of reactive postural adjustments in the elderly

Author(s)

Marina Brito Silva

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Escola de Educação Física e Esportes (EEFE/BT)
• Defense date: 2013-09-25

Examining board members

Luis Augusto Teixeira; Sandra Regina Alouche; Andre Fabio Kohn; Luis Mochizuki; Paula Fávaro Polastri Zago

• Advisor: Luis Augusto Teixeira

Abstract

Previous studies have shown that automatic postural responses can be influenced by cortical processing associated with learning, prior experience, and precue. However, scarce behavioral evidence has been provided about how postural responses are modulated by different contextual information in the elderly. The present investigation aimed at evaluating how different contextual information through prior experience and precueing about direction and/or time of basis of support rotation modulate reactive postural responses of elderly. The task consisted of recovering stable upright body balance in response to rotation of the support basis, inducing dorsi or plantar flexion with fixed amplitude and velocity. In Experiment 1 young and elderly people performed four experimental conditions resulting from combination of visual precue about direction of rotation and prior experience through repetitive or random sequences of trials. In Experiment 2 participants were provided with precueing about direction and/or time of platform rotation. Results showed that series of trials with the same direction of rotation induced decreased center of pressure oscillation and muscular activation, whereas random series induced shorter latencies of muscular activation. Precueing about time of platform rotation induced shorter latencies of muscular activation, and precueing about direction of rotation induced decreased muscular activation (effect observed in Experiment 1 only). No differential effect of precueing was observed between age groups. Results suggest that contextual information modulates reactive postural responses, and that elderlys reactive postural responses are benefited by contextual cues in a similar way as young adults responses (AU)

• FAPESP's process: 10/00307-0 - Central organization in the generation of anticipatory and reactive postural adjustments in the elderly
• Grantee: Marina Brito Silva
• Support Opportunities: Scholarships in Brazil - Doctorate