Kyle Schumacher, PT, DPT, LAT
You may have seen it in Men’s Health, Forbes, on ESPN, your local news channel with professional athletes or witnessed in it in person at the gym. Bands, straps, or cuffs being applied or wrapped around the person’s upper arms or upper thighs to try and cut off some of the blood supply to the limb while they do some sort of exercise. Why would someone do this? Does it work? Is it a fad? Is it safe? BFR is gaining popularity throughout the performance (gym, fitness center, weight room) setting and rehabilitation setting. This post’s main focus will be on its application in the rehab setting.
What is it?
Personalized BFR is the application of a cuff/tourniquet system around the upper arm or upper thigh which is then inflated to your specific pressure to occlude a portion of the arterial blood flow into the extremity and the venous outflow of blood from the extremity. This practice has been going on for ages, but within the last 5-10 years, it has been gaining popularity through extensive research. This is designed to only be performed for a short period of time approximately 5-6 minutes while an exercise is performed. The system is then deflated for 1 minute, and then re-inflated for another exercise. Typically, one session consists of about 5 exercises or about 30 minutes with a one minute deflate between each exercise.
Why would someone use BFR?
If you’re suffering from an injury, preparing for surgery, or recovering from surgery, usually you’re in pain. Typically, when you’re in pain, it hurts to move the involved extremity, so you don’t. This usually leads to weakness or atrophy, spasm, and more pain. The last thing you even want to think about doing is exercising or trying to get stronger. In order to see strength or hypertrophy in an extremity, you have to be able to exercise or lift heavy around 70% of your 1 rep max (RM). That is almost impossible for someone to do a week out of most injuries or surgeries. With BFR, you’re able to achieve those strength and hypertrophy gains at only 20% of your 1 RM. This allows us, as rehabilitation professionals, to begin strengthening and hypertrophy phases much sooner in the rehab protocol.
How does it work?
The exact mechanism on how BFR affects the body, specifically the muscle tissue, is still being extensively research, but it is thought that this is achieved through multiple factors:
- Cellular swelling: BFR produces an influx of fluid into the muscle cell that threatens the cell’s ultrastructure forcing it to kick in muscle protein synthesis to keep the cell from dying.
- Anaerobic metabolism & Systemic Response: BFR limits the amount of blood reaching the muscle tissue above and below the cuff causing the body to try and create energy in the absence of oxygen. This leads to increased production of metabolites (i.e. lactate and hydrogen) which trick the brain and body into producing more growth hormone thus kicking muscle strengthening and hypertrophy into overdrive.
Is it safe?
Personalized BFR has been performed on thousands of individuals in peer-reviewed literature with little to no side effects. Numerous studies have looked at BFR in conjunction with low load exercise and its associated with venous thromboembolism (i.e. a blood clot). The totality of studies seems to reveal minimal adverse events pertaining to blood clots after using BFR and clinically reported events have not been reported. BFR may not be suitable for everyone. It should be carefully applied in those with varicose veins as there has been a case of rupture of a vein following BFR training. One should get clearance for their physician to perform BFR training if: they are on blood thinners, have a history of blood clots, have a presence of a stent or port. It is contraindicated in those who have an infection in the limb or open wound, active blood clot, active cancer, and sickle cell anemia. Typically, a rule that could be followed is if the individual is allowed to have surgery where a tourniquet will be applied and used, they should be able to perform BFR.
Can I just use knee wraps, a blood pressure cuff, or some other advertised device to do BFR?
The safest pneumatic tourniquet devices are those that are certified with the FDA and indicated for personalized BFR. These devices are able to calculate each individual’s limb occlusion pressure (LOP) and what percentage to exercise underneath that LOP. What does this mean: the tourniquet will measure how much pressure it takes to fully occlude blood going into and coming back out of the limb. Once that pressure is measured, the system will then be able to calculate how much pressure needs to be applied to maintain your personalized exercise pressure. BFR with low load is usually performed around 80% of one’s LOP in the leg and 50% of one’s LOP in the arm. Therefore, the device will find the individual’s LOP and the person will exercise at either 80% or 50% of that and the whole time the device is continuing to measure the blood pressure to maintain that level of occlusion. Anyone not using a device certified by the FDA for BFR leaves the individual susceptible to liability in the event of an adverse event.
Who should use BFR?
Clinically, BFR has been applied to numerous diagnoses with positive results: Achilles tendon repair, pre and post-operative knee reconstructions (ACL, PCL, MCL), UCL (Tommy John) reconstructions, total joint replacements, rotator cuff tears and repairs, muscle strains, tendinopathies, cartilage repairs, fractures, and the list can go on. So no, it is not just for the professional or collegiate athlete, it is appropriate for the weekend warrior, the individual who has general deconditioning, the baby boomer following a knee scope or rotator cuff repair, the high school basketball player with jumper’s knee, or the grandparent following a total hip or knee replacement. As long as the person does not have an absolute contraindication listed above, and in conjunction with clearance from their physician, BFR can be applied to most cases where strengthening and hypertrophy are encouraged and needed.
Blood flow restriction training is gaining in popularity in the area, and could possibly become the standard of care as more and more research proves its efficacy, safety, and faster positive outcomes. As more and more people start to become exposed to it as a rehab modality, educate yourself and all involved in its application for maximum benefit and safety.
**APTSM does NOT currently offer this treatment, as it is still in the research phase. This blog is strictly informational and meant to serve as a conversation piece. BFR should ONLY be performed by a licensed physician or physical therapist-- do not try this at home. Please contact us if you have any further questions regarding BFR and the treatments we currently offer.
