Whole-body vibration as a potential method to improve phonatory function: investigation of five vibration settings

Abstract

BACKGROUND: Whole-body vibration, the oscillatory movement transmitted from a mechanical vibration source to the body, has been shown to cause neurogenic adaption of the skeletal muscles and facilitate muscular function improvement (Cardinale & Wakeling, 2005). Phonatory function, in terms of intensity, has been found to improve following whole-body vibration at around 10 -15 Hz when compared to vibration below 10 Hz (Yokoyama and Hoshino, 1973). AIM: To identify whether whole-body vibration, compared to resonant voice training, would improve voice related quality of life and vocal function, in terms of maximum frequency and intensity. METHOD: Adults with self-perceived voice problems were randomly assigned to one of three treatment groups: 1) resonant voice training, 2) whole-body vibration, or 3) a combined treatment. Vocal folds were visually examined. Pre- and post-treatment outcome measures included: maximum fundamental frequency, intensity and voice related quality of life. Participants attended individual therapy three times a week for three weeks. RESULTS: All treatment groups showed an improvement in their voice related quality of life following treatment. The whole-body vibration and resonant voice training groups showed similar improvements on vocal function outcomes, with an increase in maximum fundamental frequency and intensity. Conclusion: Similar vocal function outcomes were observed after nine sessions of whole-body vibration or resonant voice training.