Blood flow restriction (BFR) training is a strengthening technique occasionally used to help gain muscle function after an injury or surgery. It is done by temporarily restricting blood flow to a muscle during exercise. The patient will wear a specially designed cuff that is monitored by a machine or by a blood pressure type dial. The pressure is set within the current BFR guidelines for UE and for LE. 

This method is most appropriate when high training loads are not appropriate, such as after surgery, injury, or in cases of significant loss of muscle mass. Blood flow restriction strengthening uses low-intensity exercise to achieve strength typically seen with high-intensity training. If the person does not have an injury or weakness and can perform exercises 80-90% of their 1 rep max, then BFR may not benefit them as much as a person recovering from injury or surgery.

BFR has been around since 1966 with some studies from as early as 1937

Blood flow restriction training places a muscle under mechanical stress. (This mechanical stress also occurs during high-intensity muscle strengthening.) The result of this high stress helps improve muscle hypertrophy, or growth, via:

• Release of hormones specific to muscle growth

• Activation of specific stem cells for muscle growth

• Cell swelling within muscles

• Hypoxia (decrease in oxygen)

While these factors occur during high load training, they may be achieved during low load training by restricting blood flow to the muscle. This restriction creates an environment where muscle growth can occur even if the training loads are kept to a minimum, something that may be important after injury or surgery.

As your body is healing after surgery, you may not be able to place high stresses on a muscle or ligament. Low load exercises may be required, and blood flow restriction training allows for maximal strength gains with minimal, and safe, loads.