Effect of self-generated whole-body vibration versus externally induced whole-body vibration on vocal fatigue in females : a randomized, non-inferiority trial

Abstract

This study evaluated the effect of self-generated whole-body vibration on reducing vocal fatigue in female adults comparing with externally induced whole-body vibration treatment. Twenty-four female adults (mean age = 23.96 years) were randomly assigned into either one of the following three groups: externally induced whole-body vibration group (N = 8), self-generated whole-body vibration group (N = 8) and a placebo group of vocal resting with a sham hand-held vibrational massager (N = 8). All participants performed a vocal-loading task of Karaoke singing for at least 95 minutes. Each participant in the three groups received 10 minutes of vibration or sham vibration according to the group allocation. Vocal function ability as measured by the highest fundamental frequency produced and a self-reported vocal fatigue score were used as outcome measures. Measurements were taken at baseline (pre-fatigue), after a singing task (post-fatigue) and post-intervention. Results revealed the externally induce whole-body vibration was significantly better in improving vocal fatigue than the self-generated whole-body vibration and sham vibration groups.