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

Abstract

PURPOSE: The purpose of this investigation was to determine the effect different relative pressures of blood flow restriction (BFR) had on muscle oxygen saturation (SmO2) while walking at 3.0 mph. METHODS: 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 SmO2 changes were measured using near infra-red spectroscopy (NIRS) bilaterally 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. SmO2 measurements were analyzed using two-way repeated measures ANOVA while other measurements were analyzed using one-way repeated measures ANOVA. RESULTS: 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), F (1.432, 40.08) = 32.74, p < 0.0001, initial ΔSmO2, F (1.8, 52) = 28, p < 0.001, and final ΔSmO2, F (1.359, 38.04) = 9.631, p = 0.0016. Tukey’s post hoc analysis of differences in ADS revealed significant differences for all comparisons except at 40% vs 80% LOP (p = 0.0821) for the GM. Post hoc analysis of initial ΔSmO2 revealed a significant difference for all comparisons except at 40% vs 80% (p = 0.555) for the VL. Multiple comparisons for final ΔSmO2 only showed a significant difference at 40% vs. 100% (p = 0.0029) and 80% vs 100% (p =0.0079) for the VL. CONCLUSION: The results did not support our hypothesis that there would be no significant difference in SmO2 between 40%, 80%, and 100% LOP. Multiple comparison results differed between ADS, initial ΔSmO2, and final ΔSmO2. ADS data was used to reflect the magnitude of SmO2 desaturation on the VL and GM during each occlusion stage. The magnitude of SmO2 desaturation was statistically significant between LOP% except for between 40% and 80% LOP of the GM.