Acute Blood Flow Responses to Varying Blood Flow Restriction Pressures in the Lower Limb

Bjoern Hornikel; Keith S Saffold; Jacob A Mota; Michael R Esco; Michael V Fedewa; Stefanie A Wind; Lee J Winchester

Acute Blood Flow Responses to Varying Blood Flow Restriction Pressures in the Lower Limb

Int J Exerc Sci. 2023 Jan 1;16(2):118-128. eCollection 2023.

Authors

Bjoern Hornikel^{1

2}, Keith S Saffold¹, Jacob A Mota^{1

3}, Michael R Esco¹, Michael V Fedewa¹, Stefanie A Wind⁴, Lee J Winchester¹

Affiliations

¹ Department of Kinesiology, The University of Alabama, Tuscaloosa, AL, USA.
² Department of Epidemiology, The University of Alabama-Birmingham, Birmingham, AL, USA.
³ Deparment of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA.
⁴ Department of Educational Studies in Psychology, Research Methodology, and Counseling, The University of Alabama, Tuscaloosa, AL, USA.

PMID: 37114195
PMCID: PMC10124717

Abstract

The purpose of this study was to investigate lower limb blood flow responses under varying blood flow restriction (BFR) pressures based on individualized limb occlusion pressures (LOP) using a commonly used occlusion device. Twenty-nine participants (65.5% female, 23.8 ± 4.7 years) volunteered for this study. An 11.5cm tourniquet was placed around participants' right proximal thigh, followed by an automated LOP measurement (207.1 ± 29.4mmHg). Doppler ultrasound was used to assess posterior tibial artery blood flow at rest, followed by 10% increments of LOP (10-90% LOP) in a randomized order. All data were collected during a single 90-minute laboratory visit. Friedman's and one-way repeated-measures ANOVAs were used to examine potential differences in vessel diameter, volumetric blood flow (VolFlow), and reduction in VolFlow relative to rest (%Rel) between relative pressures. No differences in vessel diameter were observed between rest and all relative pressures (all p < .05). Significant reductions from rest in VolFlow and %Rel were first observed at 50% LOP and 40% LOP, respectively. VolFlow at 80% LOP, a commonly used occlusion pressure in the legs, was not significantly different from 60% (p = .88), 70% (p = .20), or 90% (p = 1.00) LOP. Findings indicate a minimal threshold pressure of 50%LOP may be required to elicit a significant decrease in arterial blood flow at rest when utilizing the 11.5cm Delfi PTSII tourniquet system.

Keywords: Blood flow velocity; hemodynamics; regional blood flow.