Effects of Different Percentages of Blood Flow Restriction on Muscle Oxygen Saturation While Walking.

The purpose of this investigation was to determine the effect of different relative pressures of blood flow restriction (BFR) on muscle oxygen saturation (SmO) while walking at 3.0 mph (4.83 kph). Fifteen physically active healthy adults performed seven 5-minute stages of walking at 3.0 mph with a blood flow restriction cuff applied to the proximal portion of the left or right leg while bilateral SmO changes were measured using near infra-red spectroscopy (NIRS) on the medial head of the gastrocnemius (GM) and vastus lateralis (VL) muscles. Other measurements including heart rate (HR), blood pressure (BP), rating of perceived exertion (RPE), and ground contact time balance (GCTB) were also collected. SmO measurements were analyzed using two-way repeated measures (RM) ANOVA while other measurements were analyzed using one-way RM ANOVA. We observed a significant main effect of LOP% (limb occlusion pressure) on the difference in total area of desaturation that occurred during each occlusion stage (ADS), < 0.0001 η = .336, early ΔSmO, < 0.0001 in both the GAS η = .132 and VL η = .335. The results suggest that there are significant differences in SmO desaturation between 40%, 80%, and 100% LOP. Our findings suggest that incremental increases in LOP will bring about greater SmO desaturation during walking and may therefore induce a larger adaptive response on the muscles. However, increased LOP% may intensify perception of effort.