Effectiveness of Blood Flow Restriction Exercise Therapy to Reduce Pain in Knee Osteoarthritis Patients

Study Overview
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Brief Summary
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Resistance training of knee extensor muscles is being used in physiotherapy management in knee osteoarthritis (OA) to improve pain and physical function. Blood flow restriction (BFR) has been suggested to improve pain and increase muscle strength in healthy subjects and certain diseases. Although there are clinical studies suggesting improvements in knee osteoarthritis symptoms after 4-12 weeks of exercise with BFR, the acute effects of the intervention have not been known. This study aims to assess the effectiveness of low load exercise therapy combined with BFR on acute pain reduction and within 24 hours post-intervention on people with knee OA compared to a placebo group. This study will take place in Athens, Greece, as part of the postgraduate MSc program of the Physiotherapy department of the University of West Attica.

Detailed Description
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A double-blinded randomised clinical trial with a total of 42 participants will be randomly assigned to the intervention (n=21) or the control group (n=21). The intervention group will complete a single exercise session with BFR 80%, 30% 1RM, while the control group will have sham BFR, 30% 1RM. Pain Pressure Threshold (PPT) will be assessed with the use of a digital pressure dynamometer.

Official Title
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Effectiveness of Blood Flow Restriction (BFR) Exercise Therapy to Reduce Pain in Knee Osteoarthritis (OA) Patients. A Double-blinded Randomised Clinical Trial

Conditions
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Knee Osteoarthritis

Intervention / Treatment
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* Device: Blood Flow Restriction (BFR)
* Device: Sham Blood Flow Restriction (sham BFR)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Current osteoarthritis clinical diagnosis according to either European League Against Rheumatism (EULAR) or American College of Rheumatology (ACR) criteria VAS/NRS Knee pain ≥3/10 during activity Exclusion Criteria: Previous experience with BFR Has followed knee exercise or kinesiotherapy program in the past 3 months New medicines in the past 3 months Any lower limb surgery in the past 6 months Knee arthroplasty surgery (Knee replacement) Any active healing process affecting walking (fracture, sprain, strain, etc.) Diagnosed with rheumatologic/neurologic disease affecting functionality Diagnosed or history of heart or vascular diseases Diagnosed with respiratory/metabolic disease Personal history of cancer Cognitive problems Pregnancy (only for female participants) Any other indication not to participate in exercise
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: BFR group<br>The intervention group will receive resisted knee extension 30% of 1RM with blood flow restriction. | Device: Blood Flow Restriction (BFR)<br>* Exercise: Bilateral knee extension at range 90ο-0ο Load: 30% 1RM BFR: Yes, 80% at both legs Sets: 4 Reps: 30-15-15-15 Rest: 30'' between sets Tempo: 2-0-2-0 Participants of the intervention group will receive an exercise protocol with blood flow restriction once and will be measured for changes in PPT by the use of a digital dynamometer. Exercise protocol will be four sets of bilateral knee extension 90ο-0ο, reps per set 30-15-15-15, tempo 2-0-2-0 and rest 30 sec between sets. In order to determine the training load 30% of 1RM, participants will perform bilateral knee extension in range 90ο-0ο with pain-free maximum resistance. The derived 1RM will be used to determine the 30% 1RM load. Blood flow restriction will be applied at 80% by using pressure cuffs. The cuffs will be applied to the proximal thigh. Cuff pressure needed for a 100% vascular occlusion will be determined for each individual at a seated and relaxed position.<br>* Other names: Kaatsu;|
| Placebo Comparator: Sham BFR group<br>The control group will receive resisted knee extension 30% of 1RM with sham blood flow restriction. | Device: Sham Blood Flow Restriction (sham BFR)<br>* Exercise: Bilateral knee extension at range 90ο-0ο Load: 30% 1RM BFR: Yes, Sham BFR, 10mm Hg at both legs Sets: 4 Reps: 30-15-15-15 Rest: 30'' between sets Tempo: 2-0-2-0 Participants of the control group will receive an exercise protocol with sham blood flow restriction once and will be measured for changes in PPT by the use of a digital dynamometer. Exercise protocol will be four sets of bilateral knee extension 90ο-0ο, reps per set 30-15-15-15, tempo 2-0-2-0 and rest 30 sec between sets. In order to determine the training load 30% of 1RM, participants will perform bilateral knee extension in range 90ο-0ο with pain-free maximum resistance. The derived 1RM will be used to determine the 30% 1RM load. Sham technique for blood flow restriction will be applied by using pressure cuffs inflated at 10mm Hg. The cuffs will be applied to the proximal thigh. Cuff pressure will be applied for each individual at a seated and relaxed position.<br>* Other names: Sham Kaatsu;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of Pain Pressure Threshold (PPT) from baseline | Pain will be measured with a digital dynamometer. Raise of the PPT value means a better outcome | At baseline, Post 5 minutes, Post 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of Dynamic weight-bearing Assessment of Pain (DAP) from baseline | DAP is correlating VAS/NRS pain reporting scales with the functional test of 30-second Chair Stand Test (30s-CST) | At baseline, Post 5 minutes, Post 24 hours | 
| Change of 30-second Chair Stand Test (30s-CST) from baseline | 30s-CST is a functional assessment evaluating leg strength and dynamic balance, the more repetitions one can do during the 30'', the better the outcome | At baseline, Post 5 minutes, Post 24 hours | 
| Change of pain score from baseline with the use of reporting scales Visual Analogue Scale (VAS) / Numeric Rating Scale (NRS) | Pain reporting scales as NRS are using 0-10 grades to measure how big the pain is, 10 is for the worst pain | At baseline, Post 5 minutes, Post 24 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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chronic pain