BFR Training and Knee Osteoarthritis

Knee osteoarthritis (KOA) is a chronic, progressive degenerative joint disease characterized by cartilage and bone degeneration, synovial inflammation, and structural changes. Clinically, it presents with pain, morning stiffness, swelling, crepitus, and limited range of motion, leading to functional impairment, gait abnormalities, and reduced quality of life. Globally, KOA affects \~302 million people. In Saudi Arabia, prevalence rises from 30.8% (ages 46-55) to \>60% (ages 66-75), with higher rates in older, female, and obese individuals. Key risk factors include aging, female sex, obesity, prior knee injury, and genetics. The condition imposes significant health burdens and socioeconomic costs.

The International Classification of Functioning, Disability, and Health (ICF) identifies KOA as a major cause of physical disability. Pain, restricted motion, and muscle weakness drive quality-of-life decline. While pharmacological treatments exist, physical therapy interventions (education, exercise, weight loss) are crucial, though their success depends on patient behavioral change.

Traditional biomedical education inadequately addresses chronic pain. Pain neuroscience education (PNE) teaches the biology and physiology of pain, supported by a biopsychosocial assessment. PNE is increasingly used by physiotherapists for chronic pain management.

Quadriceps weakness contributes to functional decline in KOA. Conventional high-load resistance training may exacerbate joint pain; thus, low- to moderate-intensity training is recommended. Blood flow restriction training (BFRT) partially restricts arterial inflow and occludes venous outflow during low-load exercise, originally developed as "kaatsu training" in Japan. BFRT is used in rehabilitation and performance training across healthy individuals, athletes, older adults, and hypertensive patients. Factors affecting adaptations include occlusion pressure, type (continuous/intermittent), exercise intensity, and volume. Low-load resistance with BFRT reduces joint pain and increases muscle strength and mass in older adults, including those with KOA risk factors.

A systematic review of six RCTs on BFRT in KOA patients showed significant pain improvement in four studies, but meta-analysis did not confirm a significant difference. Combining exercise therapy and education is recommended for musculoskeletal pain reduction; pain education alone reduced healthcare spending by 45% over three years. However, physical therapists underutilize pain management approaches, and knowledge gaps remain barriers.

Controlled clinical studies on BFRT in KOA are lacking. This randomized trial aims to evaluate whether BFRT, PNE, and standard treatment improve pain, function, muscle thickness, and patient satisfaction in KOA patients.