A Doppler Ultrasound Method to Measure Vascular Responses to Walking

Abstract

Measuring leg blood flow (LBF) in response to walking can offer unique insights regarding mechanical and physiological functions of the leg. However, current gold-standard methods of measuring LBF are invasive. Alternatively, Doppler ultrasound is a promising method to noninvasively measure LBF. The purpose of this study was to demonstrate the utility of a novel ultrasound scanning technique to measure vascular reactivity to walking. Participants walked on a 0{degrees} slope, followed by a -5{degrees} and 5{degrees} slope in random order. A Doppler ultrasound probe was fastened over the dominant-side common femoral artery using a custom 3D printed bracket. LBF was recorded immediately before and after each walking condition. Baseline LBF was not significantly different before each walking condition (p = .577), but there were significant differences in post-walking (p < .001), with uphill causing the greatest increase in LBF. These results suggest that our ultrasound technique is repeatable during quiet standing and can detect the differences in blood flow across different walking intensities. Our method may be valuable to understand how the circulatory system responds to various locomotion tasks, and how cardiovascular disease may impair locomotor functions.