Authors: Dustin Edmonds, Devin Needs, Riley Fisher
Mentors: Brent Feland
Insitution: Brigham Young University
Research question
How does localized vibration increase blood flow? We know that localized vibrations increase blood flow. We wanted to know if this is done through the release of hormones, specifically histamines.
Relevant research context
Research on blood flow has been done using whole-body vibration but research on the effects of localized vibration on arterial blood flow is scant. To date, there are only a couple of research articles on massage guns despite their prolific use in the sports industry. No research to date has attempted to assess the mechanism behind the increased blood flow that results from localized vibration.
Methods
Twenty-one participants completed this study, 11 males and 10 females, mean age of 22.1 +/- 2.0 years. The mean male height 181.3 +/- 9.6 cm and weight 80.7 +/- 19.0 kg. The mean female height is 169.2 +/- 7.5 cm, and the mean weight is 64.5 +/- 9.3 kg. All subjects were “recreationally active” and exercised at least three times a week for thirty minutes a day. Excessive activity or high-level athletes were not allowed to participate.
Each subject received localized vibration to the gastrocnemius (vibration of 47 Hz for 10 minutes) with and without an antihistamine drug by reporting to the lab on 2 separate days. The non-antihistamine trial was performed first, followed at least 24 hours later by ingesting an antihistamine (180 mg of fexofenadine) 1 hour before the trial. Blood flow in the popliteal artery was measured using an ultrasound. Measurements (mean and peak blood velocity, volume flow, popliteal diameter, and heart rate) were taken before localized vibration treatment and then taken at intervals for 19 minutes after the treatment.
Analysis
We used a cell-means mixed model to statistically compare the effect of vibration on blood flow with and without antihistamines. This was done by evaluating the blood flow response immediately post vibration and comparing that to baseline values for both control and antihistamine conditions.
Results and Conclusion
There was a significant increase in blood flow without antihistamine while administration of antihistamine blunted the blood flow response and resulted in an insignificant increase in blood flow. In the tests with the antihistamine, we saw an insignificant change in blood flow immediately post vibration, resulting from the localized vibration.
From this experiment, we hypothesize that increased blood flow from localized vibration is due to activation of mast cells which release histamines and that this cellular activation is force dependent.