Honors Program

Midway Honors

Date of Award


Thesis Professor(s)

Courtney D. Hall

Thesis Professor Department

Physical Therapy

Thesis Reader(s)

Brandi Eveland-Sayers, Michael W. Ramsey


The vestibular system senses changes in head position and is responsible for the brain’s perception of verticality. Vestibular dysfunction is caused by deficits in the semicircular canals and/or otolith end-organs with resulting symptoms including dizziness, vertigo, and unsteadiness. Current vestibular rehabilitation focuses on compensation of the semicircular canal-mediated vestibulo-ocular reflex through gaze and balance exercises. Little is known about rehabilitation of otolith organ function, yet research findings suggest that fall risk may be related to otolith dysfunction. A recent case study demonstrated improvement of vertical perception and balance following off-axis rotation in a rotary chair, showing that such stimulation may be useful for compensation of otolith organ dysfunction. The purpose of our research was to further investigate off-axis rotation as a possible treatment method by evaluating subjective visual vertical (SVV) in healthy controls. Two distance parameters (3.5 cm off-axis and 7.0 cm off-axis) were applied to the rotary chair, with results measured through the SVV test, visual analog scales (VAS), and the balance tilt test (BTT). The magnitude of SVV shift following off-axis rotation was measured in both the 3.5 cm and 7.0 cm off-axis experiments. The greater distance parameter (7.0 cm) did not increase SVV shift magnitude more than the 3.5 cm parameter; yet, resulted in greater symptom intensity as measured through the VAS. These findings led to the conclusion that a distance parameter of 3.5 cm off-axis is optimal for stimulating the otolith organs. This discovery may be helpful in future research utilizing off-axis rotation as a possible treatment method for vestibular patients suffering from otolith dysfunction.


East Tennessee State University

Document Type

Honors Thesis - Withheld

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