IMPACT OF BLOOD FLOW RESTRICTION (BFR) TRAINING ON MUSCLE STRENGTH IN POST KNEE SURGERY REHABILITATION. AN EVIDENCE BASED REVIEW- A NARRATIVE REVIEW

Abstract

Background: Blood Flow Restriction Training (BFRT) has gained increasing attention as a rehabilitation strategy that enables significant muscular and functional adaptations using low-load exercise. This approach is particularly relevant for patients who cannot tolerate high mechanical loads due to pain, postoperative restrictions, or degenerative and neurological conditions. Despite growing clinical use, evidence regarding its effectiveness across diverse populations and rehabilitation contexts remains heterogeneous, necessitating a structured synthesis of available findings.

Objective: To evaluate the effectiveness and clinical relevance of BFRT combined with low-load resistance training on muscle strength, hypertrophy, pain, functional performance, and rehabilitation outcomes across knee-related musculoskeletal and selected neurological conditions.

Methods: This narrative review synthesized evidence from 15 quantitative studies, including randomized controlled trials, cohort studies, and case series. Study populations included individuals with knee osteoarthritis, anterior cruciate ligament reconstruction, total knee arthroplasty, patellar tendinopathy, patellar fracture surgery, multiple sclerosis, older adults, trained males, and physically inactive adults. Interventions involved active or passive BFRT combined with low-load resistance, aerobic, or functional exercises. Occlusion pressures ranged from 30% to 80% of arterial occlusion pressure, and intervention durations varied between 4 and 12 weeks, with some studies reporting follow-up up to 52 weeks. Outcomes were assessed using validated strength, pain, balance, functional performance, and quality-of-life measures.

Results: Across studies, BFRT groups demonstrated superior improvements in muscle strength (approximately 20–35%) compared with conventional low-load training (5–15%). Pain scores were reduced by 30–50% in BFRT groups versus 10–25% in controls. Functional outcomes, including timed mobility and sit-to-stand performance, improved by 25–40% following BFRT. Postoperative populations showed reduced quadriceps atrophy and better early functional recovery. Adverse events were rare and mild.

Conclusion: BFRT is a safe, effective, and versatile rehabilitation modality that enhances recovery and functional outcomes using low-load exercise, offering a valuable alternative to traditional high-load resistance training.