Table of Contents
International Journal of Brain Science
Volume 2015, Article ID 804206, 9 pages
http://dx.doi.org/10.1155/2015/804206
Research Article

Effects of Hand Vibration on Motor Output in Chronic Hemiparesis

1School of Rehabilitation, Faculty of Medicine, Université de Montréal, Canada
2Center for Interdisciplinary Research in Rehabilitation, Institut de Réadaptation de Montréal, Montreal, QC, Canada
3Physical Therapy Department, Universidade Estadual do Centro-Oeste, Rua Simeão Camargo Varela de Sá, 03 Vila Carli, 85040-080 Guarapuava, PR, Brazil

Received 28 August 2014; Revised 5 January 2015; Accepted 19 January 2015

Academic Editor: Michele Ferrara

Copyright © 2015 Sibele de Andrade Melo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background. Muscle vibration has been shown to increase the corticospinal excitability assessed by transcranial magnetic stimulation (TMS) and to change voluntary force production in healthy subjects. Objectives. To evaluate the effect of vibration on corticospinal excitability using TMS and on maximal motor output using maximal voluntary contraction (MVC) in individuals with chronic hemiparesis. Methodology. Nineteen hemiparetic and 17 healthy control subjects participated in this study. Motor evoked potentials (MEPs) and MVC during lateral pinch grip were recorded at first dorsal interosseous muscle in a single session before, during, and after one-minute trials of 80 Hz vibration of the thenar eminence. Results. In hemiparetic subjects, vibration increased MEP amplitudes to a level comparable to that of control subjects and triggered a MEP response in 4 of 7 patients who did not have a MEP at rest. Also, vibration increased the maximal rate of force production () in both control and hemiparetic subjects but it did not increase MVC. Conclusion. Motor response generated with a descending cortical drive in chronic hemiparetic subjects can be increased during vibration. Vibration could be used when additional input is needed to reveal motor responses and to increase rate of force generation.