Date of Award

5-2018

Degree Type

Thesis

Degree Name

Departmental Honors

Department

Health, Physical Education, and Recreation

Abstract

Background: Stability is known to decrease as we age, but currently we know very little about how the body's balance system, the vestibular system, contributes to balance control in older adults, particularly while walking and climbing stairs. The purpose of this study was to take the first step in understanding vestibular contribution to balance control during locomotion and stair negotiation, and how this changes with age.

Methods: Ten young adults and six older adults ascended and descended a nine-step staircase 78 times and walked on a treadmill for 10 minutes to complete a total of 300 complete steps in each condition. During each trial, a small amplitude, random electric current was applied behind the subject's ears to stimulate the nearby vestibular nerve, and surface electromyography was recorded from eight leg muscles. We used time-dependent correlations (coherence) to determine how the vestibular stimulus influences muscle behavior, how this influence is modulated by the phase of the step cycle.
Results: The vestibular stimulus influenced select muscles in a phase-dependent manner over the step cycle in both age groups. In general, in muscles where vestibular influence over the muscle's behavior was apparent in both the older and younger groups, the influence was stronger and longer-lasting in the older adults. Additionally, prominent vestibular influence over a muscle was observed in more muscles in the older group than the younger group.

Conclusions: This offers a first look at the functional contribution of the vestibular system to maintaining balance during locomotion and stair negotiation in older adults. These results suggest that as we age, we may rely more on vestibular signals in order to maintain balance during locomotion and stair negotiation.

Included in

Kinesiology Commons

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Faculty Mentor

Chris Dakin

Departmental Honors Advisor

Eadric Bressel