As the 2022 Olympics begin, blood flow restriction received press attention as the “hot new fitness trend”.
First developed in 1966 by power lifter Yoshiaki Sato, this “new trend” has transformed the physical therapy industry in the rehabilitation of a wide variety of patients.
Blood flow restriction therapy (BFR) is an innovative treatment that has been found to be effective in helping patients recover their strength and regain their former lifestyle. As a form of low-load resistance training, BFR focuses on improving muscle function and improving the patient’s quality of life.
More common uses include rehab for orthopedic injuries and post surgery rehab. Patients who cannot lift or tolerate heavier weights, including those with arthritis, benefit from the therapy.
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What is blood flow restriction training?
Blood flow restriction training is a form of temporary occlusion. This causes a brief period of ischemia or low blood flow to the working muscle. The goal of blood flow restriction training is to create mild muscle fatigue by blocking circulation to the active muscle. This technique can be used on the upper or lower extremities.
BFR mimics the effects of high intensity exercises by restricting the amount of oxygen that is carried to the muscle. This process can lead to increased strength and hypertrophy at a faster rate than normal exercise.
The technique might sound a little unorthodox. As physical therapists, we are always looking for ways to help our patients and make therapy even more effective. Use of BFR can improve clinical outcomes with less visits to therapy and strain on the body. In turn, this results in a faster return to the patient’s goals.
In a hurry? Read our Blood Flow Restriction F.A.Q
How does BFR work?
During BFR training, a blood flow restriction cuff is placed proximal to the muscles being trained. We inflate the cuff in order to 
partially occlude the arterial blood flow to the targeted muscle and partially occludes the venous blood returning to the heart.
Under these conditions, the patient exercises at a low intensity and high repetition. This technique can be used on the upper or lower extremities.
These conditions mimic the “anaerobic” state of exercise synonymous with high-intensity training. This allows for comparable benefits to heavy weight lifting with low-load activities.
These conditions stimulate the release of myogenic stem cells, growth hormone and insulin-like growth factor systemically.
In effect, the therapy creates strength and hypertrophy gains in the targeted limb, but can also affect other muscle groups in the body.
Who can benefit from blood flow restriction therapy? Who should not use BFR?
Patients who are looking to return to sports or an active lifestyle are good candidates for BFR. This can be a young patient after an ACL injury or rotator cuff surgery. or an older patient after TKA or shoulder surgery, BFR is applicable and beneficial.
BFR should not be used for patients who have
- venous thromboembolism
- peripheral vascular compromise
- sickle cell anemia
- extremity infection
- lymphadenectomy
- cancer or tumor
- extremity with dialysis access
- acidosis
- open fracture
- increased intracranial pressure vascular grafts
- medications known to increase clotting risk.
How is BFR used in Physical Therapy? For injured athletes?
BFR can be applied to patients/athletes early on in the rehab process. We can simulate the effects of high intensity training using BFR and low resistance weight. This can help enhance strength at a faster rate allowing for a quicker return to sports.
After joint replacement therapy, older patients use BFR to build strength. This helps with a faster return to walking without assistive devices, navigating stairs or uneven surfaces, and a quicker return to normal activities.
Also, BFR is a useful treatment style for pre-operative patients with short courses of therapy. The BFR allows for accelerated strengthening and hypertrophy. This better prepares the patient for post-op therapy and provides a better foundation for starting post-op physical therapy.
Benefits of BFR Training
- Muscle Hypertrophy – Increased muscle size due to increase in protein content of the muscle fibers
- Production of myogenic stem cells – cells responsible for the repair and growth of muscle fibers
- Release of hormones – Growth hormone and insulin-like growth factor are released. These hormones are responsible for muscle recovery and collagen synthesis
- Muscle strength – reduction of oxygen during training can lead to anabolic reaction and increase in strength
A report in the Journal of The American Academy of Orthopaedic Surgeons says, “Low-load BFR training can increase muscle strength, endurance, cross-sectional area, and potentially sport-specific performance. As a result, low-load BFR training holds promise for enhanced recovery from injury.”
Risks/Disadvantages
Because BFR is a low-intensity exercise regarding the level of stress on the joint, there are minimal risks to bodily tissues and structures. There are contraindications to BFR that could put a patient at risk, which is why before BFR is ever utilized the patient should be screened and asked about any medical history that might put them at risk for vascular complications.
The actual occurrence of blood clot development is low. Especially, when patients receive proper screening by the therapist.
The most common contraindications:
- current blood clot
- impaired circulation
- sickle cell anemia
- active infection in the limb
- populations with precautions include those with poor circulatory systems, diabetics, and those with kidney complications
How to Get Started with Blood Flow Restriction Therapy
We recommend you seek professional guidance when using blood flow restriction. Remember, Olympic athletes work constantly with sports scientists and trainers.
First, you should research clinics in your area that offer BFR. Upon finding a clinician, make sure your medical history gets screened appropriately. Also, the clinician should ask questions regarding any possible precautions or contraindications.
Many companies manufacture BFR units. Some offer training and certification courses to become familiar with their units. A physical therapy license is required to administer BFR. You should complete BFR with a practitioner who trained with their piece of equipment or attended BFR training.
In the end, BFR is a safe intervention as long as contraindications are monitored and asked prior to administration.
