If You Want Blood Flow Restriction, We've Got It!
Posted on 1/2/2019 by Grant Shanks, P.T., OCS
For many patients recovering from injuries and surgeries, a period of immobilization in a cast or sling and/or restrictions on weight-bearing and activity is necessary to ensure proper recovery and tissue healing. Immobilization and lack of use comes with a significant cost, though: decreased muscle strength and size, known medically as atrophy.
Even after the restrictions are lifted, it takes months to recover to pre-injury levels of strength and ability. However, recent research has led to exciting advancements in what is possible when it comes to regaining muscle strength, size and ability following injury and/or surgery. The development of Blood Flow Restriction training has opened up new doors for patients and the therapists who treat them.
What is Blood Flow Restriction (BFR) training?
Blood Flow Restriction (BFR) training uses external pressure – via a tourniquet – to reduce (restrict) arterial blood flow to working muscles and completely occlude (block) venous blood flow return to the heart. By doing so, one can achieve substantial hypertrophy (muscle growth), strength and endurance changes while using significantly decreased loads/weight. The gains in these areas of performance are consistent with what is typically observed with heavy load lifting.
To this point, the American College of Sports Medicine has shown that optimal muscle strength and hypertrophy can be achieved by lifting at high intensities, defined by their research as: eight-to-10 upper and lower body exercises, performed two-to-three times per week for six-to-eight weeks at intensities greater than 65 percent of the individual’s one repetition maximum (RM). Certainly, this is not possible for the immobilized/injured/post-surgical patient. Utilizing BFR, these same gains in strength and hypertrophy have been observed using only 20 percent of an individual’s one RM and in just two-to-three weeks.
How does BFR work?
While the exact mechanisms are not completely understood, it appears to be a combination of factors related to muscle physiology:
Decreased oxygen to the muscle causes a build-up muscle-building metabolic products.
A preferential recruitment of larger, fast-twitch muscle fibers.
An increase in growth hormone and stem cells following exercise with BFR.
Increased muscle protein synthesis via the extreme “muscle pump” following BFR.
BFR Leg What kind of device/equipment is used for delivering BFR?
By definition, anything that restricts blood flow is a tourniquet, which is considered a medical device and falls under FDA Class I regulations. In order to determine how much blood flow restriction to create in a limb (upper or lower extremity), an individual’s limb occlusion pressure (LOP) must be determined. In order to do this, a Doppler is used to assess for the presence or absence of a pulse.
Once enough pressure has been created by the tourniquet, the pulse will be absent. This amount of pressure is the LOP and then the working pressure is a percentage of this amount – either 80 percent for the lower extremity or 50 percent for the upper extremity. Machines that have a built-in Doppler are considered the gold standard. A hand-held Doppler could also be used.
Who would benefit from BFR?
Patients who are recovering from surgery to the upper or lower extremity and cannot bear weight, move their extremity and/or have been weakened by conditions may be good candidates to receive BFR. Some conditions include:
Total joint replacements
Rotator cuff repair/injury
Upper extremity fracture
Lower extremity fracture
Knee arthroscopy (knee scope)
Achilles tendon repair/injury
Shoulder labral repair/injury
Hip labral repair/injury
How do I know if BFR is right for me?
Your physical therapist will be able to go through the indications (reasons to perform) and any possible contraindications (reasons not to perform) BFR with you.
BFR is a new and growing area of rehabilitation, strength and conditioning and not all physical therapists have been trained and educated on the matter. Contact your local Select Physical Therapy or NovaCare Rehabilitation center to see if BFR is available.
By: Grant Shanks, P.T., OCS, area sports medicine coordinator for Select Physical Therapy in Tennessee. Grant also serves as center manager of our Mt. Juliet location.
Select Physical Therapy and NovaCare Rehabilitation are part of the Select Medical Outpatient Division family of brands.