Bilateral blood flow restriction of the legs worsens acute walking balance of older adults – a full factorial randomised experiment

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BACKGROUND: Multiple sessions of walking with blood flow restriction (BFR) of the legs can improve cardiovascular fitness, muscle strength and hypertrophy in older adults. However, it is unclear whether BFR impairs walking balance acutely, potentially increasing falls risk during BFR training for this at-risk population. RESEARCH QUESTION: Does bilateral BFR of the legs acutely worsen walking balance of older adults? METHODS: Ten older adults (mean age: 73, SD: 3 y) walked for 10 min on a treadmill at 50 %, 60 % and 70 % of their fast walking speed, with 10 cm-wide cuffs on the proximal thigh of both legs inflated to 0 % (no cuff), 40 % or 60 % of arterial occlusion pressure. We measured four characteristics of walking balance which were selected a priori and combined into a gait quality index predictive of future falls in older adults: autocorrelation of vertical accelerations; magnitude and harmonicity of sideways accelerations; and magnitude of the dominant period of forwards accelerations. RESULTS: Walking balance worsened with BFR, independent of walking speed, for all outcomes except the magnitude of the dominant period of forwards accelerations, with worse balance observed with increasing cuff pressure. Compared to no BFR, gait quality declined 12 % when walking with 50 % occlusion and declined 20 % with 60 % occlusion (p < 0.001). SIGNIFICANCE: Our findings suggest that BFR results in poorer acute walking balance, with a dose-response relationship for cuff pressure. Supervised walking trials are warranted to further assess the safety of BFR training in community settings and whether these balance-related changes may stimulate beneficial chronic balance adaptations.

BFR may increase acute falls risk during training in older adults; hypothesis-generating for mitigation strategies in prospective trials.