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May 8, 2024 Blood Flow Restriction Physical Therapy Post operative physical therapy Pre-operative Physical Therapy Return to Sport Strength and Conditioning

Blood Flow Restriction: How Does It Aid in Your Patients’/Clients’ Recovery, Strengthening, and Healing?

Blood flow restriction (BFR) has recently been gaining popularity in outpatient physical therapy although its origins date back to the late 1960s. While the history behind this technique is fascinating, it is not the focus of this discussion. For those curious about the development of BFR, exploring the works of Dr. Yoshiaki Sato provides insightful articles on the subject.

What is BFR?

BFR is a technique that involves using inflatable bands to restrict venous (oxygen deficient) blood flow while still allowing arterial inflow. This method can offer numerous benefits for patients’ recovery, strengthening, and healing.

Reported benefits of BFR training include:

Enhanced muscle strength
Skeletal Muscle Hypertrophy
Mitigation of post-traumatic atrophy and strength loss
Increased neuromuscular activity
Reduction in pain signaling
Improved bone mineral density
Enhanced cardiovascular endurance
Improvement in VO2

How Does BFR Work? An Overview

The mechanism of action of BFRT involves several proposed physiological responses, including fiber recruitment, metabolic response, cellular swelling, anabolic hormone response, and activation of the mTOR pathway for protein synthesis. These combined effects make blood flow restriction a valuable tool in physical therapy practice and can contribute significantly to aiding patients in their journey towards better health and injury/surgery recovery.

When the veins are restricted during muscle contraction, several changes occur. Blood can still enter the muscle through the deeper arteries but cannot exit through the superficial veins. This leads to increased pressure within the capillaries, pushing fluids across endothelial membranes into the surrounding tissues, including muscle fibers. The rise in tissue fluids helps draw nutrients from the blood vessels into the tissues. As a result, blood accumulates in the veins, causing a backup in the arteries and reducing flow as metabolites accumulate in the system. Within these blood vessels, the endothelial cells react to the changing PH levels of the blood releasing an increased amount of Nitric Oxide (NO). NO enhances vasodilation in blood vessels and creates a “pumped” sensation.

The lack of oxygen creates a hypoxic environment within the tissue causing the release of Vascular Endothelial Growth Factor (VEGF). The signaling protein chemical plays a crucial role in forming new blood vessels (angiogenesis) and their supportive networks. Once new blood vessels form, they enhance oxygen and nutrient delivery to tissues, improving the lactate threshold.

Using blood flow restriction (BFR) can prompt the hypothalamus to release growth hormone (GH) and insulin-like growth factor-1 (IGF-1). These hormones play a crucial role in muscle cell regeneration, reproduction, and fat breakdown. GH boosts muscle strength and power by enhancing protein synthesis, while IGF-1 is vital for muscle and bone growth, muscular hypertrophy, and regulating DNA synthesis.

BFR induces early fatigue and increases motor unit recruitment similar to high-load training under low loads. Furthermore, BFR accelerates the activation of fast-twitch muscle fibers, mirroring the functional and metabolic changes seen in high-intensity exercises but at lower intensities with BFR.

BLUF (Bottom Line Up Front):

BFR may help decrease muscle atrophy in various scenarios:
- During immobilization
- In the acute injury phase
- Among geriatric populations
- In response to inflammation
BFR can enhance protein synthesis.
BFR can promote cellular swelling
BFR can influence metabolism by:
- Increasing lactate build-up
- Stimulating Growth Hormone release
BFR can also affect:
- Enhanced collagen synthesis
- Stimulation of IGF-1 release from the kidneys
- Activation of satellite cells for repair
BFR down-regulates Myostatin levels (a protein that hinders muscle growth), encouraging muscle growth and bone remodeling.
BFR offers pain relief.
BFR boosts VO2 Max levels.

Who May Benefit From BFR

Pre-Operative patients: to prevent atrophy and maintain muscle strength
Post-Operative patients: for pain relief and the opportunity to strengthen skeletal muscles and tendons with reduced strain and load
Elderly patients: to lessen joint stress
Athletes: to enhance strength and cardiovascular stamina
BFR offers benefits independently of exercise, offering a promising option to combat muscle loss in postoperative, immobilized, or hospitalized individuals.

How To Introduce BFR Into Practice

Consult your local state practice acts to confirm whether incorporating BFR into your practice falls within your scope. Although certification is not mandatory in most states, it is recommended to enroll in a reputable course for proper training and utilization of this modality.

While we do not endorse particular cuffs or protocols in this article, our aim is to educate readers so they can make informed decisions when selecting cuffs that best suit the requirements of their patient or client demographic. Although BFR may not be suitable for everyone you work with, it can be a valuable tool to enhance your skills and address specific cases when applied correctly.