Over the past year or longer I have been offering Blood Flow Restriction training (BFRT) to FoleyPhysicalTherapys list of services. From a continuing education standpoint this is an area with an obscene amount of research to completely immerse oneself in and I decided to jump in to training and application in the early part of 2020.
In the Musculoskeletal/orthopedic care world treatments such a platelet rich plasma (PRP), stem cell use (in specific select forms only in the US), glucosamine and nutraceutical injections have come to the forefront of physician care options. They are considered "regenerative" treatments, loosely defined as using the bodies own materials to heal. It is early in the evolution/application and evidence is still in flux regarding the efficacy of these tools, but there is an encouraging progress with these proactive treatments.. BFRT is a similar game changer in my world and I can use it on nearly all patients in various degrees, including non injured folks, to make meaningful changes in their strength.
The concept of BFRT is based on principles of muscle physiology and cell growth. You have to first appreciate how cool muscle is before you can appreciate how interesting this technique can be. Muscle is at a base a series of cells and bundles of those cells are ultimately fibers and bundles of the fibers compose the muscle in various shapes and cross sectional sizes, think of finger muscles compared to large rear end muscles. With strength training often fatigue and oxidative stress causes a deconditioned person to fatigue before fully working all of the muscle tissue being targeted. So gaining strength becomes a long process of first gaining the conditioning required to begin working the muscle fully to fatigue and then doing that often enough at high enough levels to gain a measurable change in strength.
We sometimes mistake the early ability of being able to adapt to lifting heavier weight as having actually gained strength, when in fact early on we are often simply gaining the neuromuscular ease to lift the weight more readily. Muscles must reach a fatigue phase which is uncomfortable in order to recruit more cells to work. this results in strength gains and also in size gains later. Size depends on body type and predisposition or genetics as well as age.
In a BFRT session a surgical grade blood pressure looking tourniquet is placed on a limb and while using a doppler to monitor blood flow, the tourniquet is inflated to briefly occlude the blood flow in to the limb. This sensation is pretty similar, though much more compressive sensation, to having your blood pressure measured. A percentage of that "limb occlusion pressure" (LOP) is then utilized during training so that the exercising limb has some vascular flow, but hence the name, a designated amount of restriction. This occlusion introduces a greater mechanical stress, hormonal response and other biochemical affects which appear to result in greater muscle fiber recruitment, sooner and at lighter loads. The value of this to post surgical limbs, or even simply deconditioned muscle is pretty exciting because gaining strength, not just bigger cross section of muscle but actual strength change, is tough especially post injury or surgery when tissue tolerance may be restricted. Also for post surgical patients sometimes the permissible loads for several weeks are no greater than isometric contractions. The potential strength loss during this period can be devastating. BFRT demonstrates quite consistently that training at various LOPs and this is the key part - low loads (even isometrics) is superior to low load training (or isometrics) alone. This is not just for post surgical patients or only for athletes, however. Many deconditioned patients who cannot lift much weight and fatigue quickly will benefit from making the adaptation phase mentioned above, more productive and efficient. The concept of strength training in to the uncomfortable/muscle fatigue zone is a tough challenge and many of us simply aren't trying hard enough to strength train when we do lift weights. BFRT is in no way less uncomfortable, that stage still must occur, but the value of adding BFRT in reducing the time to see measurable gains cannot be over looked.
Please reach out with questions or comments so I can share more about this exciting adjunct to physical therapy!