Main content

Broad Spectrum (3-250 Hz) Vibratory Stimulation of the Plantar Surface Targeted to Activate Different Subpopulations of Cutaneous Mechanoreceptors Induces Directionally-Specific Whole Body Postural Adjustments

Show full item record

Title: Broad Spectrum (3-250 Hz) Vibratory Stimulation of the Plantar Surface Targeted to Activate Different Subpopulations of Cutaneous Mechanoreceptors Induces Directionally-Specific Whole Body Postural Adjustments
Author: Hayes, Chris
Department: Department of Human Health and Nutritional Sciences
Program: Human Health and Nutritional Sciences
Advisor: Bent, Leah
Abstract: Cutaneous afferent information undoubtedly contributes to the control of upright posture in man but exactly how the different subpopulations of cutaneous mechanoreceptors are involved in the regulation of bipedal stance remains unclear. The present work was designed to further elucidate whether subpopulations of cutaneous mechanoreceptors induce postural responses following broad spectrum vibratory stimulation of the sole of the foot. Specifically, there were two goals for this thesis. The first goal was to develop a method of delivering vibratory stimuli (3-250Hz) to the plantar surface (heel and forefoot) of upright subjects as they stood on a force-platform. The second goal was to conduct a study examining the effects of the vibratory stimuli on postural control. Stimuli were delivered at intensities just supra-threshold for perception and that were designed to activate specific mechanoreceptor populations. Healthy, young adult subjects (n = 9) were tested while standing upright with a narrow base of support and their eyes closed. Measures of Centre of Pressure and Centre of Mass displacement were calculated using an AMTI force plate and Optotrak 3020 kinematic system. The results showed that directionally specific, whole-body, postural adjustments away from the site of stimulation could be elicited following each frequency of vibratory stimulation (3, 15, 60, 250Hz). The postural adjustments following stimulation at the heel were greater than those elicited following stimulation at the forefoot. Interestingly, there were no significant differences in amplitude of sway following different frequencies of stimuli. These results suggest that mechanical indentations of different parts of the plantar surface, across a wide range of frequencies, induce reproducible responses. All of these responses, across each frequency, were aligned to be away from the site of stimulation. This is consistent with the view that the sole of the foot serves as a dynamometric map. What we have added is that postural responses can be elicited across the full spectrum of frequencies that could be encountered in normal postural perturbations. This work thus contributes to the accumulating evidence of the importance of cutaneous feedback in postural control and provides indirect evidence that each mechanoreceptor population is involved in the control of standing posture.
URI: http://hdl.handle.net/10214/7848
Date: 2014-02
Rights: Attribution 2.5 Canada
Terms of Use: All items in the Atrium are protected by copyright with all rights reserved unless otherwise indicated.


Files in this item

Files Size Format View
Hayes_Chris_201402_MSc.pdf 1.248Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record

Attribution 2.5 Canada Except where otherwise noted, this item's license is described as Attribution 2.5 Canada