Can Individuals Be Taught to Sense the Degree of Vascular Occlusion? A Comparison of Methods and Implications for Practical Blood Flow Restriction.

Abstract

Bell, ZW, Spitz, RW, Wong, V, Yamada, Y, Song, JS, Abe, T, and Loenneke, JP. Can individuals be taught to sense the degree of vascular occlusion? A comparison of methods and implications for practical blood flow restriction. J Strength Cond Res 36(12): 3359-3365, 2022-The study objective was to determine whether subjects could be conditioned to a relative blood flow restriction pressure in the lower body and compare 2 separate conditioning methods (unconstrained vs. constrained). Thirty-five subjects completed 4 visits, involving measurements for arterial occlusion and pressure estimations at 5 minutes and 24 hours after conditioning. The constrained method involved applying 40% of measured arterial occlusion 11 times, along with 10% above and below this pressure. The unconstrained method was time-matched, involving a series of inflations to 40% arterial occlusion for 12 seconds and then deflated for 22 seconds. Data are presented as mean differences (95% credible interval) unless otherwise noted. The absolute error between conditioning methods was found to be similar at 5 minutes (-1.1 [-5.9, 3.7] mm Hg) and 24 hours (-2.4 [-7, 2.2] mm Hg) after conditioning. The constant error differed between methods at 5 minutes [-8.2 (-14.4, -1.9) mm Hg] but was similar at 24 hours (-2.5 [-8.5, 3.6] mm Hg; H0: 0.680; H1: 0.068; and H2: 0.252) after conditioning. The bias and 95% limits of agreement for the unconstrained method were -3.9 (-33.8, 25.9) mm Hg at 5 minutes and -2.9 (-32, 26.1) mm Hg at 24 hours. The agreement for the constrained method was 4.2 (-28, 36.5) mm Hg at 5 minutes and -0.54 (-37.3, 36.2) mm Hg at 24 hours. Conditioning methods produced similar levels of absolute error, indicating that either method may offer a viable means of pressure application. Most estimates were between 20 and 60% of arterial occlusion pressure. Additional conditioning sessions may be needed to narrow this range at the individual level.