By Drew Yanker, PT, DPT
Clinic Manager—Frontenac, MO
Blood Flow Restriction Therapy or “BFR” is the act of applying a tourniquet to a limb to reduce the oxygenated blood to the working muscles and allow a build-up of venous blood and lactate to stimulate muscle growth. While this may sound scary at first, the process is very regulated and safe in healthy individuals. Your therapist will first measure your “limb occlusion pressure” using a Doppler and pressure gauge. This is the pressure it takes to completely restrict arterial blood to the limb (it feels like getting your blood pressure taken). Not to worry though, you will not be under this pressure for long. Generally, 50%-80% of your limb occlusion pressure is all that is required to achieve maximal results. Once your individual pressure has been calculated, your therapist will demonstrate the exercise you will be performing. Almost any therapeutic exercise can be performed with BFR, however, there will be changes to the amount of resistance, repetitions, and rest required. BFR exercises can be performed for most muscle groups which will be directed by your therapist to enhance your rehabilitation results.
Why does restricting blood flow promote muscle growth? Well, the answer is complicated, but essentially the lack of oxygen to the muscle stimulates the contraction of specific muscle fiber types that are most responsible for strong contractions. Not only that but due to the lack of oxygen in the muscle the body will stimulate to recruit more of them than they normally would during exercise with relatively light resistance. So now you are focused on the correct fiber types needed for strengthening and using more of them during your exercise. In addition, the occlusion of venous blood has even more benefits. By not allowing venous blood to return, the muscles waste product, Lactate, is not allowed to be cleared from the muscle. This accumulation then stimulates anabolic hormones to be produced and circulated throughout the body. This further promotes muscle growth and strength gains. What this all means is that with the addition of properly performed BFR, a patient can use much lighter resistance to achieve muscle growth than would normally be required. This places much less strain on injured joints which makes BFR therapy a safe and fast option for your rehabilitation.