Blood Flow Restriction (BFR) Therapy

Introduction

Blood flow restriction (BFR) therapy is a rehabilitation technique that allows a person to build muscle strength while using relatively light weights or low levels of resistance. During BFR therapy, a specially designed inflatable cuff is placed around the upper arm or upper leg and inflated to partially reduce blood flow leaving the limb while still allowing blood to enter. The patient then performs exercises using light resistance, typically only 20–30% of the weight they could normally lift. Although the exercise is relatively easy, the temporary reduction in blood flow causes the muscles to work harder and creates changes within the muscle that stimulate muscle growth and strength. Researchers believe BFR increases the release of growth-promoting hormones, recruits more muscle fibers, and stimulates muscle protein production, allowing patients to gain strength while placing less stress on healing joints, tendons, and bones.

Uses of Blood Flow Restriction Therapy

Blood flow restriction therapy is used in a variety of rehabilitation settings, particularly when patients are unable to safely perform traditional heavy strengthening exercises. It is commonly used following orthopaedic surgeries such as anterior cruciate ligament (ACL) reconstruction, knee replacement, rotator cuff repair, meniscus surgery, Achilles tendon repair, and some fracture surgeries. BFR therapy may also benefit patients recovering from tendon injuries, muscle strains, arthritis, or prolonged immobilization after an injury. In athletes, BFR may be used to help maintain muscle strength during recovery from injury. Because it allows strength gains with lighter loads, it may help reduce muscle loss while protecting healing tissues during the early phases of rehabilitation.

Example of a Blood Flow Restriction Program

A typical blood flow restriction program is supervised by a physical therapist or other trained healthcare professional. A specialized cuff is placed around the upper portion of the arm or leg and inflated to a pressure that partially restricts blood flow. The patient then performs low-resistance exercises such as straight-leg raises, leg presses, knee extensions, calf raises, biceps curls, or shoulder strengthening exercises. A common program consists of four sets of an exercise performed in a 30-15-15-15 repetition pattern, with about 30 seconds of rest between sets while the cuff remains inflated. The cuff is then deflated after the exercise before moving on to the next activity. Sessions usually last 15 to 30 minutes and are performed 2 to 3 times per week as part of a broader rehabilitation program.

Risks of Blood Flow Restriction Therapy

Although blood flow restriction therapy is generally considered safe when performed by trained professionals using appropriate equipment, it is not suitable for everyone. Temporary discomfort, muscle soreness, bruising, or numbness can occur during treatment. More serious complications, although uncommon, include nerve injury, muscle injury, or the development of a blood clot. Patients with a history of deep vein thrombosis (DVT), severe peripheral artery disease, uncontrolled high blood pressure, significant vascular disease, sickle cell disease, active infection in the limb, or certain bleeding disorders may not be appropriate candidates for BFR therapy. For these reasons, patients should always be screened for medical conditions before beginning treatment, and BFR should only be performed under the guidance of a healthcare professional who has received specialized training.

Summary

Blood flow restriction therapy is a rehabilitation technique that helps patients build muscle strength while lifting light weights. By partially restricting blood flow during exercise, the muscles are challenged in a way that promotes strength and muscle growth without placing excessive stress on healing tissues. BFR therapy is increasingly used after orthopaedic surgery and during rehabilitation from many musculoskeletal injuries. When performed correctly and in appropriately selected patients, it can be an effective addition to a comprehensive rehabilitation program. However, because it is not appropriate for everyone and carries some risks, it should always be performed under the supervision of a physical therapist or other trained healthcare professional.

Edited by Stephen Pinney MD, July 2nd 2026.