Blood Flow Restriction (BFR) can accelerate rehabilitation from injury and from post – surgical recovery.
By Dr. John R. Mishock, PT, DPT, DC
BFR Exercise Part I: Accelerating Rehabilitation from Injury and Post-Surgical Recovery
By Dr. John R. Mishock
Aaron Rodgers, the NFL superstar quarterback of the New York Jets, sustained an Achilles tendon tear and subsequent repair in August. He has made a miraculous recovery, with the opportunity to return to on-field training in 77 days instead of the usual return of elite athletes in six to nine months. If the New York Jets were in playoff contention, he could have returned to competition months ahead of schedule this season. One rehabilitation technique dramatically enhancing Rodgers’s recovery was Blood flow restriction exercise (BFR). (USA Today, 2023)
BFR is the brief intermittent occlusion of arterial and venous blood flow using a medical-grade tourniquet while at rest or exercising. Before using the tourniquet on an arm or thigh, limb occlusion pressure (LOP) is determined using a diagnostic ultrasound. The LOP is the minimum pressure needed to sufficiently occlude deep arteries and superficial veins. Once the occlusion pressure is known, the individual performs exercise using 40-50% LOP for the arms and 60-80% for the thigh. These pressures assure normal arterial flow to the muscle while slowing the venous return to the heart.
BFR training was first utilized in Japan by Doctor Yoshiaki Sato in 1966. Sato came up with the idea while sitting in a traditional Japanese posture when he suddenly realized that the blood flow was restricted to his calves and feet, giving him the same burning sensation he experienced during exercise. In the last 57 years, BFR training has been refined and perfected, with many studies showing scientific validity in increasing muscle size and strength in healthy people, older people, and the injured. (Wilk et al. 2020)
In 2018, the American Physical Therapy Association added BFR as part of the professional scope of practice for physical therapy. It is also widely promoted and applied to college and professional athletes in the NFL, NBA, MLS, and NHL. Studies have confirmed the positive effect of BFR training on healthy basketball, rugby, football, track and field, cycling, rowing, tennis, and volleyball athletes. Research has shown that the BFR exercise can enhance athleticism in squat jumps, explosive power, maximum and repetitive sprinting ability, first-step quickness, and change directions. (Wang et al. 2022)
Is BFR safe?
Even regular exercise creates muscle damage and some risk of injury. A study of 12,600 individuals who had experienced BFR training found that the most common side effects of BFR were muscle pain and soreness due to exercise. Some had temporary numbness, but this response diminished and disappeared as the cuff was released. (Nakajima et al. 2006)
Another study showed minimal side effects with venous thrombus (0.055 %), pulmonary embolism (0.008%), and rhabdomyolysis at (0.0008%). The authors concluded that BFR was safe and effective for most individuals. To optimize safety, BFR is contraindicated in individuals
with a history of deep venous thrombosis, hereditary thrombotic tendency, pregnant women, a-fib or heart failure, malignancy, lymphedema, infection, Sickle cell anemia, and those with significant cardiovascular risk factors. As with all exercise, consulting your doctor before beginning any exercise program is advised.
Can BFR reduce pain?
BFR can cause pain reduction during or after a single bout of exercise. Nine studies on lower extremity pain showed a 61% reduction compared to a control. (Shuoqi et al. Am J Phys Med Rehabil, 2021) The pain reduction is due to a phenomenon widely known as exercise-induced hypoalgesia. BFR increases the release of our body’s natural pain relievers (endogenous opioids and endocannabinoid mechanisms). Pain relief is found at a local or remote site and is higher than conventional exercise for patients with foot, ankle, knee, hip, lower back, wrist, elbow, and shoulder pain. (Karanasios et al. 2023)
Can BFR help post-surgical rehab for the lower extremity?
Atrophy before and after surgery is a significant problem in the rehabilitation setting. The knee muscles (quadriceps femoris) can lose between 20-33% muscle volume from injury until three weeks after the ACL reconstruction. (Gerber et al. Eur J Phys Rehabil med, 2016) Weakness in that knee and lower extremity can last up to 3 years post-operatively (Meier et al. J Geriatr Phys Ther, 2009). BFR can be used for rehabilitation of post-surgical hip, knee, ankle, and foot. BFR can be used before surgery (prehab) and then two weeks post-operatively through the conclusion of outpatient rehabilitation.
For the knee (ACL recovery), twenty studies have shown an accelerated rehab compared to conventional knee protocols, with up to a 14% increase in strength and reduced pain following sessions. One study found a 50% reduction in muscle atrophy with BFR. (Takarada et al. Med Sci Sports 2000) Significant muscle hypertrophy has been noted after as short as six training days. (Yining et al. Orth Jour of Sports Med, 2023)
For Achilles tendon repair, BFR exercise allowed for strength and power improvements of the calf and ankle by 55.8% and 47.1% in 6 weeks. The strength gains permitted individuals to jog and run at 6-8 weeks post-operatively. (Yow et al. J Foot Ankle Surg 2018)
Can BFR help with muscle and tendon injury (tendinopathy or tendonitis)?
Tendon problems account for up to 30% of all musculoskeletal conditions requiring medical attention. (Canosa et al., 2022) Thirteen studies have evaluated the use of BFR with non-surgical tendon injuries such as ankle (Achilles), knee (patellar), shoulder (supraspinatus), and elbow (lateral elbow) for pain, strength, function, and mechanical tendon properties. Studies have shown reduced pain, increased strength, improved tendon thickening, and increased tendon vascularity, all lending to a faster return to functional activities. (Burton et al. Front in Sports Act Living, 2022, Karanasios et al. J Orthop Sports Phys. 2022
Can BFR improve osteoarthritis and Rheumatoid arthritis?
OA and RA are the two most common arthritis forms affecting 60 million Americans. Arthritis not only causes pain but also significant atrophy of the muscles that are designed to support the joint. BFR studies have shown pain relief, increased muscle mass and strength, and increased walking ability with greater gait speed. (Dos Santos et al. PloS 2021)
In BFR part II, I will review the mechanisms of BFR exercise and how it can enhance exercise for healthy individuals to improve strength, power, and explosiveness for enhanced sports performance.
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Dr. Mishock is one of only a few clinicians with doctorate-level degrees in both physical therapy and chiropractic in the state of Pennsylvania. He has authored two books; “Fundamental Training Principles: Essential Knowledge for Building the Elite Athlete”, “The Rubber Arm; Using Science to Increase Pitch Control, Improve Velocity, and Prevent Elbow and Shoulder Injury,” both can be bought on Amazon.