Feasibility of Blood Flow Restriction Resistance Exercise for Patients with Intermittent Claudication

Intermittent Claudication (IC) is a common and debilitating symptom of peripheral arterial disease (PAD) resulting in significant reduction in exercise performance and quality of life. Supervised exercise programmes are part of first-line treatment for IC proving highly effective for improving exercise performance and alleviating symptoms. Despite this, supervised exercise programmes have poor adherence in part to patients’ inability to tolerate IC related pain during walking exercise highlighting the need for alternative exercise modes. Blood flow restriction resistance exercise (BFR-RE) is a technique that facilitates local muscle hypoxia during resistance exercise to induce hypertrophy, strength, and muscular endurance. BFR-RE presents an exciting alternative modality to improve exercise performance in IC patients though requires research on safety, feasibility, and efficacy. This research explored the acute perceptual, affective, and physiological responses to resistance exercises performed at low-load with BFR (LL-BFR), low-load (LL) and moderate-load (ML) in healthy young and older adults; examined the inter-day reliability of a physical function test battery in IC patients sought to determine suitability of the test battery and smallest worthwhile change for each measure; and conducted a randomised controlled trial to evaluate the safety, feasibility, and efficacy of an 8-week LL-BFR resistance exercise programme in IC patients. No adverse events were recorded during this body of work that was attributed to the protocols or procedures administered. LL-BFR was shown to be more demanding than LL and ML predominately through increased pain (p ≤ 0.024, d = 0.8 – 1.4). However, this did not lead to decrements in affective response and fatigue post exercise. Excellent reliability (≥ 0.92 ICC) of the physical function test battery was observed in IC patients and the minimum likely change (76% chance) was calculated for each measure. The feasibility trial observed high adherence (LL-BFR = 78.3%, LL = 83.8%) and completion rates (LL-BFR = 93%, LL = 87%). Significant clinical improvement (>35 m) in the six-minute walk test (6MWT) was achieved in 86% of patients in LL-BFR but only 46% of patients in LL. Additionally, time to claudication pain during 6MWT was likely increased (44.7 s [20.8, 68.6]) for LL-BFR and likely unchanged (4.4 s [-32.4, 23.6]) for LL. This thesis supports BFR-RE as a safe, feasible and potentially effective exercise mode for IC patients

Low-Intensity Resistance Exercise with Blood Flow Restriction for Patients with Claudication: A Randomised Controlled Feasibility Trial

Background: Claudication is a common and debilitating symptom of peripheral artery disease, resulting in poor exercise performance and quality of life (QoL). Supervised exercise programmes are effective rehabilitation for patients with claudication, but they are poorly adhered in part to high pain and effort associated with walking, aerobic and resistance exercise. Low-intensity resistance exercise with blood flow restriction (BFR) represents an alternative exercise method for individuals who are intolerant to high-intensity protocols. The aim of this study was to evaluate the feasibility of a supervised BFR programme in patients with claudication. Methods: Thirty patients with stable claudication completed an 8-week supervised exercise programme and were randomised to either BFR (n = 15) or a control of matched exercise without BFR (control; n = 15). Feasibility, safety, and efficacy was assessed. Results: All success criteria of feasibility trial were met. Exercise adherence was high (BFR = 78.3%, control = 83.8%), lost to follow-up was 10%, there were no adverse events. Clinical improvement in walking was achieved in 86% of patients in BFR but only 46% of patients in the control. Time to claudication pain during walking increased by 35% for BFR but was unchanged for the control. QoL for BFR showed to have improved mobility, ability to do usual activities, pain, depression, and overall health at follow-up. Conclusion: A supervised BFR programme is feasible in patients with claudication and has potential to increase exercise performance, reduce pain, and improve QoL

Comparative perceptual, affective, and cardiovascular responses between resistance exercise with and without blood flow restriction in older adults

Older adults and patients with chronic disease presenting with muscle weakness or musculoskeletal disorders may benefit from low-load resistance exercise (LLRE) with blood flow restriction (BFR). LLRE-BFR has been shown to increase muscle size, strength, and endurance comparable to traditional resistance exercise but without the use of heavy loads. However, potential negative effects from LLRE-BFR present as a barrier to participation and limit its wider use. This study examined the perceptual, affective, and cardiovascular responses to a bout of LLRE-BFR and compared the responses to LLRE and moderate-load resistance exercise (MLRE). Twenty older adults (64.3 ± 4.2 years) performed LLRE-BFR, LLRE and MLRE consisting of 4 sets of leg press and knee extension, in a randomised crossover design. LLRE-BFR was more demanding than LLRE and MLRE through increased pain (p ≤ 0.024, d = 0.8–1.4) and reduced affect (p ≤ 0.048, d = −0.5–−0.9). Despite this, LLRE-BFR was enjoyed and promoted a positive affective response (p ≤ 0.035, d = 0.5–0.9) following exercise comparable to MLRE. This study supports the use of LLRE-BFR for older adults and encourages future research to examine the safety, acceptability, and efficacy of LLRE-BFR in patients with chronic disease

Evaluating the between-day reliability and likelihood of change of a test battery incorporating vastus lateralis muscle thickness, ankle-brachial pressure index, maximal voluntary torque, and six-minute walk test in patients with claudication

Objective The study aims to evaluate the between-day reliability of a proposed test battery for patients with claudication that can be used for monitoring the effectiveness of exercise interventions and other therapeutic strategies tailored to this patient population. Methods Twenty-five men with claudication were recruited. The test battery consisted of the Vastus Lateralis muscle thickness (VL-MT), ankle-brachial pressure index (ABI), unilateral isometric knee extension maximal voluntary torque (MVT) and 6-minute walk test (6MWT). A single investigator conducted the tests for each patient on two separate testing sessions (T1 and T2) 5–7 days apart. Results Good to excellent reliability was observed for VL-MT (ICC = 0.95, 95% LOA = ±3.10 mm, SEM = 0.81 mm), ABI (ICC = 0.97, 95% LOA = ±0.10, SEM = 0.02), MVT (ICC = 0.97, 95% LOA = ±24.0 N·m, SEM = 6.31 N·m), 6MWT distance (ICC = 0.99, 95% LOA = ±39.6 m, SEM = 11.0 m), 6MWT time to claudication (ICC = 0.99, 95% LOA = ±30.8 s, SEM = 7.8 s), and 6MWT ratings of pain (ICC = 0.87, 95% LOA = ±2.4 CR-10+, SEM = 0.7 CR-10+ ). Analysis derived from reliability data indicates a change of 1.4 mm for VL-MT, 0.14 for ABI, 12 N·m for MVT, 25 m for 6MWT distance, 15 s for 6MWT time to claudication and 1 CR-10+ for 6MWT ratings of pain is required to be interpreted as the minimum ‘likely’ change (76% chance). Conclusions The test battery provides a reliable assessment of patients with claudication and can be widely used to evaluate the effects of exercise programmes and other therapeutic interventions. For the individual, changes in VL-MT, ABI, MVT, and 6MWT greater than the minimum likely change as a result of an exercise programme or an intervention are likely changes and less influenced by error associated with the test