Effect of Different Local Vibration Frequencies on the Multiscale Regularity of Plantar Skin Blood Flow.

Yanni Chen,Lingling Zhou,Jeannette Elliott,Fuyuan Liao,Yih-Kuen Jan,Keying Zhang

doi:10.3390/e22111288

Abstract

Local vibration has shown promise in improving skin blood flow (SBF). However, there is no consensus on the selection of the best vibration frequency. An important reason may be that previous studies utilized time- and frequency-domain parameters to characterize vibration-induced SBF responses. These parameters are unable to characterize the structural features of the SBF response to local vibrations, thus contributing to the inconsistent findings seen in vibration research. The objective of this study was to provide evidence that nonlinear dynamics of SBF responses would be an important aspect for assessing the effect of local vibration on SBF. Local vibrations at 100 Hz, 35 Hz, and 0 Hz (sham vibration) with an amplitude of 1 mm were randomly applied to the right first metatarsal head of 12 healthy participants for 10 min. SBF at the same site was measured for 10 min before and after local vibration. The degree of regularity of SBF was quantified using a multiscale sample entropy algorithm. The results showed that 100 Hz vibration significantly increased multiscale regularity of SBF but 35 Hz and 0 Hz (sham vibration) did not. The significant increase of regularity of SBF after 100 Hz vibration was mainly attributed to increased regularity of SBF oscillations within the frequency interval at 0.0095–0.15 Hz. These findings support the use of multiscale regularity to assess effectiveness of local vibration on improving skin blood flow.

Highlights

Foot ulcerations is some of the most common complications in people with diabetes mellitus [1,2].The recurrence rate of foot ulcers is estimated at about 40% within 1 year, 60% within 3 years, and 65% within 5 years [1]
The results showed that both vibration frequencies caused significant increases in skin blood flow (SBF); and 50 Hz vibration was more effective than 30 Hz
Our results showed that local vibration at 100 Hz caused a significant increase in the regularity of SBF (Figure 5C), and 0 Hz or 35 Hz vibrations did not affect the regularity of SBF (Figure 5A,B)

Summary

Introduction

Foot ulcerations is some of the most common complications in people with diabetes mellitus [1,2]. The recurrence rate of foot ulcers is estimated at about 40% within 1 year, 60% within 3 years, and 65% within 5 years [1]. The etiology of diabetic foot ulcers involves a number of factors, including peripheral neuropathy and peripheral arterial disease [3,4,5]. Peripheral arterial disease causes an impaired vasodilatory response to repetitive plantar pressure during walking. Interventions that can improve skin blood flow (SBF) and reduce plantar ischemia are needed to prevent foot ulcers in at-risk patients [1,2,5]

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Results

Discussion

Conclusion