BFR Training and Knee Osteoarthritis

Summary

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.

Conditions

• Knee Osteoarthristis

Interventions

OTHER

Standard Treatment

1. Physical Modalities (TENS, US, and superficial heat) All participants will be received conventional TENS (Chattanooga, Intellect Advanced, USA) with the following parameters: frequency, 100 Hz; pulse duration, 60 ms; amplitude-modulated frequency, 10%; and intensity adjusted to a comfortable tingling sensation. Two electrodes (single channel) were used: the first was placed over the ipsilateral lumbar region, and the second over the popliteal fossa. The duration of the TENS was 20 minutes. 2. Exercise training 1. Hamstrings stretching, 3 repetitions of 30 s , 2. Hip abduction with weights (side lying), 3 sets of 10 repetitions Hip abduction with weights (side lying), 3 sets of 10 repetitions 3. Calf raises, 3 sets of 10 repetitions 4. Calm exercises (side lying) with elastic band, 3 sets of 10 repetitions+ 5. Seated knee extension (machine), 90°-0° of knee flexion, 3 sets of 10 repetit

OTHER

Pain neuroscience education

Pain neuroscience education was used before in such cases (knee osteoarthritis). The PNE will include five dimensions with a focus on reducing fear-avoidance beliefs and catastrophic thoughts to promote self-efficacy. This educational session will be provided only by one therapist to all the participants. The session includes a verbal explanation with a visual presentation on PowerPoint with a duration of 30-45 minutes. Educational content of the session will include pictures, examples, and metaphors for explaining pain. The metaphorical alarm system will be used to describe the nervous system's sensitivity. The purpose of this session will be to establish rapport with the participants, highlight the maladaptive nature of chronic pain, emphasize the significance of pain's role in tissue protection, and improve the subjects' understanding of factors that influence pain production.

OTHER

Blood flow restriction training

For blood flow restriction, a 10 cm cuff (Theratool, China) will be placed around the most proximal portion of the exercising leg (around the bulk of the quadriceps). While the subject is seated on a chair, the pressure cuff will be inflated to 120 mmHg for 30 seconds, then deflated. The pressure cuff will then be inflated four more times, with each period increased by 20 mmHg. Each period lasted 30 seconds, and the cuff was released for 10 seconds between periods until a final pressure of 200 mmHg was reached. With the pressure maintained at 200 mmHg, the subjects then will perform a four set of leg extension exercises (75 repetitions across four sets of exercises, with 30 repetitions in the first set and 15 repetitions in each subsequent set) at the final exercise pressure, the exercise loads will be set between 20 and 40% of 1RM,for three time per week /8weeks

Sponsors & Collaborators

• University of Hail

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

40 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-06-15

Primary Completion

2026-12-30

Completion

2026-12-30

Countries

• Saudi Arabia

Study Locations