The effectiveness of blood flow restriction training on muscle strength in the rehabilitation of anterior cruciate ligament reconstruction

Abstract

Overview: After Anterior Cruciate Ligament Reconstruction (ACLR), restoring knee musculature strength is a principal goal. Blood Flow Restriction (BFR) training is a relatively novel approach in ACLR rehabilitation, which is believed to induce hypertrophic changes through various proposed mechanisms including venous occlusion. This study aims to discover the influence of BFR on knee muscle strength gain or preservation in subjects who have undergone ACLR surgery. Research question: Does Blood Flow Restriction Training (BFRT) in patients who have undergone ACLR surgery cause earlier gains in muscle strength when opposed to non-occlusive strength training? PICO Elements: Population: Subjects undergoing ACLR surgery, Intervention: BFR training, Comparison: Non-occlusive strength training, Outcome: Muscle strength and Cross-Sectional Area (CSA). Method: Databases including PubMed and HyDi were utilised to obtain relevant searches correlated with the PICO elements through keyword and Boolean Operator inputting. Inclusion and exclusion criteria were applied and using the PRISMA checklist, from the initial 245 studies screened, 6 Randomised Controlled Trials (RCTs) were chosen to be critically appraised using the CASP tool. Results: BFR training is superior to solely low-load training whilst producing comparable results in strength gain when compared to high-load training. Therefore, when patients are able to engage in high-load training, BFR does not seem to add any further benefit. However, in the early load-compromised phase of ACLR rehabilitation, BFR is advantageous as it provides lower pain and effusion levels and protects the newly inserted ACL graft due to its load-sparing properties. Conclusion: BFR is a useful rehabilitation tool in the early, load-compromised phases of ACLR rehabilitation as it provides augmented strength gains when compared to low-load training and comparable strength gains when compared with high-load training. Additionally, due to its load-sparing properties, it provides lower pain, effusion, and graft laxity scores. Implications and Recommendations for practice: Education regarding safe and effective application of BFR should be provided to primary audiences such as physiotherapists and the operated subjects. Occlusive training is optimally implemented alongside low loads in the early phases of ACLR rehabilitation whereby pain, effusion and graft laxity are common issues. Screening for precautions and contraindications and individually tailored limb occlusion pressures should lead in implementation. Future research should focus on including larger samples, broader age brackets, different graft types and longer follow-ups.