The effect of low frequency 2-10 Hz vibrations on blood circulation in lower extremities

Abstract

This pilot study gives evidence on the effect of low frequency 2-10 Hz vibration on young physically inactive subjects and associations with blood flow in limbs. For the study purposes, low frequency 2-10 Hz vibration was applied for the subjects in the lying position, and a special device, patented at Kaunas University of Technology, was used to generate low frequency vibrations. Altered temperatures in feet were measured with a thermovisual camera, which records thermal changes. Thermovisual measurement was performed in a warm room (20-21 °C). The entire procedure lasted 45 minutes. Thermovisual measurement was performed 15 minutes before vibration, 15 minutes during vibration and 15 minutes after vibration. For temperature analysis, 2 points on the subjects' feet were chosen: the central point on the foot where the highest temperature was taken and the peripheral point on the foot where the lowest temperature was measured. Heart rate variability was measured by the Elite HRV programme. The data analysis of temperature in both the central and the peripheral points of the foot under low frequency 2-10 Hz vibration showed insignificant changes in temperature and blood flow; however, the differences determined were insignificant. The assessment of heart rate variability demonstrated that there were statistically significant differences before, during and after vibration. A tendency of the heart rate to increase shows that the heart also reacts to any changes when peripheral blood flow in feet is affected. A reverse dependence was determined: low temperature in the foot increases heart rate variability and, vice versa, increasing temperature decreases heart rate variability. It would be expedient and useful to conduct results with those of healthy subjects.

Effects of Local Vibration With Different Intermittent Durations on Skin Blood Flow Responses in Diabetic People

“…Vessel vasodilation and subsequent increases in the SBF induced by vibration are mainly regulated via two mechanisms: (i) the pulsating mechanical forces act on the endothelial cells to release NO and NO synthase (NOS), which contributes to vessel vasodilation; (ii) Simulation of polymodal receptors on the skin surface by the vibration could cause the release of neuropeptides, and further induce nerve axon reflex-related microvascular vasodilation (Sackner et al, 2005; Napoli et al, 2006; Nakagami et al, 2007). The study of Gailiuniene et al showed that low frequency 2–10 Hz vibration could not make any significant changes in foot temperature and blood flow (Gailiuniene et al, 2017). While high frequency vibration was reported to be harmful to vascular, musculoskeletal, and nervous system function (Govindaraju et al, 2010; Gailiuniene et al, 2017).…”

“…The study of Gailiuniene et al showed that low frequency 2–10 Hz vibration could not make any significant changes in foot temperature and blood flow (Gailiuniene et al, 2017). While high frequency vibration was reported to be harmful to vascular, musculoskeletal, and nervous system function (Govindaraju et al, 2010; Gailiuniene et al, 2017). According to the previous studies, vibration interventions with frequencies range from 20 to 50 Hz were beneficial to improving blood microcirculation, and 50 Hz vibration may achieve a higher increase of skin blood flow (Lohman et al, 2007, 2011; Nakagami et al, 2007; Maloney-Hinds et al, 2008; Lythgo et al, 2009; Merriman and Jackson, 2009).…”