Recovery of balance stability after stroke: immediate stability improvement by light touch and long-term improvement with sensory restriction

Author(s)

Alessandra Rezende Martinelli Conterato

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Escola de Educação Física e Esportes (EEFE/BT)
• Defense date: 2015-08-25

Examining board members

Luis Augusto Teixeira; Sandra Maria Sbeghen Ferreira de Freitas; Fernando Henrique Magalhães; Luis Mochizuki

• Advisor: Luis Augusto Teixeira

Abstract

In the present study it was assessed the effect of transitory and long-lasting procedures on the adaptation of reactive postural responses from external perturbations and during stable upright posture of participants who have undergone stroke. Experiment 1 aimed to assess the effect of light fingertip touch on a stable surface in the recovery of balance stability of post-stroke participants after mechanical perturbation and during quiet stance in comparison to healthy elderly individuals. Results in quiet stance showed that the light touch on a stable surface induced to slower and smaller magnitude center of pressure (CoP) sway. In response to an unpredictable mechanical perturbation, results showed that light touch led to smaller CoP and center of mass (CoM) displacement/sway related to the condition without touch, and smaller magnitude of muscular activation of gastrocnemius medialis (GM). Results indicated that the effect of light touch was similar between the groups. Experiment 2 aimed to assess the effect of sensory manipulation in the rehabilitation of balance stability in post-stroke participants. For this purpose, 2 post-stroke groups were subjected to training of standing balance with sensory restriction (restriction group), manipulating visual and tactile of sole of the foot information, or without sensory manipulation (integral group). Assessments were conducted before training (pretest), two days after the last session (retention 1) and one week after the end of practice (retention 2). Follow-up analyses during practice sessions indicated significantly better posture control improvements for the restriction group in comparison to the integral group. Results of the forward reach task showed greater displacement of wrist for the restriction group in the retention 1 and retention 2 test compared to the pretest, but no effect of test was found for the integral group. Results for perturbed posture indicted that for CoP amplitude and velocity, higher values were observed in the retention 1 and retention 2 test in comparison to pretest. Results for quiet stance on malleable surface showed a reduced CoP velocity for the restriction group compared to the integral group in the retention 1 and retention 2 test. Findings herein reported suggest that while extra sensory information induces posture stability and balance recovery, restriction of sensory information seems to lead to improved balance stability in participants who have undergone stroke (AU)

• FAPESP's process: 11/18173-3 - Postural responses to external perturbation in post-stroke: rehabilitation and improvement of stability by touching a vibrating surface
• Grantee: Alessandra Rezende Martinelli Conterato
• Support Opportunities: Scholarships in Brazil - Doctorate