Acute Effects of Whole-Body Vibration on Peripheral Blood Flow, Vibrotactile Perception and Balance in Older Adults. Author: Mahbub MH1, Hase R1, Yamaguchi N1, Hiroshige K2, Harada N3, Bhuiyan ANH4, Tanabe T1 Affiliation: <sup>1</sup>Deaprtment of Public Health and Preventive Medicine, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan. <sup>2</sup>Department of Physical Therapy, Kyushu Nutrition Welfare University, Kitakyushu, Fukuoka 800-0298, Japan. <sup>3</sup>Department of Nursing, Junshin Gakuen University, Graduate School of Health Sciences, Fukuoka 815-8510, Japan. <sup>4</sup>Department of Neonatology, Shaheed Sayed Nazrul Islam Medical College, Kishoreganj 2300, Bangladesh. Conference/Journal: Int J Environ Res Public Health. Date published: 2020 Feb 7 Other: Volume ID: 17 , Issue ID: 3 , Special Notes: doi: 10.3390/ijerph17031069. , Word Count: 209 BACKGROUND: Non-invasive application of whole-body vibration (WBV) has the potential for inducing improvements in impaired peripheral circulation, cutaneous sensation and balance among older adults. However, relevant studies have frequently applied high magnitudes of vibration and show conflicting and inconclusive results. Therefore, we attempted to ascertain the acute responses in those parameters from exposure of thirty older subjects to WBV of three different magnitudes, defined according to ISO 2631-1 (1997). METHODS: Each subject randomly underwent four sessions of intervention (three bouts of 1 min exposure with 1 min between-bout rests): WBV at 15, 20, or 25 Hz with a peak-to-peak displacement of 4 mm, or control condition. RESULTS: Both during and after intervention, dorsal foot skin blood flow increased significantly under 20 and 25 Hz exposure conditions with greater responses under the latter condition, the magnitude of which slightly exceeded the recommended value. Plantar vibrotactile perception showed significant increases after WBV exposure with overall greater responses under higher frequencies of vibration. In contrast, no WBV-induced change in balance was observed. CONCLUSIONS: WBV at 20 Hz with a magnitude within the recommended limit can be effective in inducing enhancements in peripheral blood flow; however, the same magnitude of vibration seems insufficient in improving balance among older adults. KEYWORDS: balance; older adults; skin blood flow; vibrotactile perception; whole-body vibration PMID: 32046205 DOI: 10.3390/ijerph17031069