Houston Methodist

Corbin Hedt

Physical therapy (or physiotherapy) helps people recover from injury to improve their physical function and performance. Throughout the last two decades, a large paradigm shift has occurred in how physical therapy (PT) is conducted, ultimately transforming the standards for more active treatment and care. Combining patient goals and needs, evidence-based practice, and clinical expertise, physical therapists strive to optimize movement to improve the human experience. However, how can PT improve your movement and activity levels when you’re dealing with pain and/or injury? The answer may lie in a seemingly archaic and inimical treatment strategy – blood flow restriction.

Blood flow restriction therapy (BFR) utilizes a specialized tourniquet cuff to reduce arterial blood flow to an exercising limb. The exercises are typically light in nature (as little as 20-30 percent of maximum effort) and are targeted at weakened musculature that may be contributing to an injury or pain. The resultant effect can be profound for the patient, quickly improving strength, mitigating atrophy, reducing pain, and increasing bone mineral density. Previously, individuals who were unable to perform strengthening exercises can now be exponentially more productive in their PT treatments, achieving their goals in a fraction of the time.

The first question patients will ask when introduced to clinical BFR – why? From a biological perspective, when we exercise at high intensity, fast speeds, and with heavy loads, our bodies will naturally want to adapt to this stimulus. Hormonal changes occur in response and we develop bigger musculature, stronger bones, and induce various cascades of healing effects that are advantageous to recovery. However, for someone undergoing a post-surgical rehabilitation or with pain that prevents high intensity exercise, these benefits might seem like a far-reaching fantasy. But what if we could recreate those same positive effects at much lighter resistances? By using BFR combined with physical therapy activities, we can effectively “trick” the body in to thinking it’s working at a much higher level with greatly reduced loads. Thus, similar biochemical responses occur, and we can achieve the same benefits of high intensity exercise without the increased risk of heavy loading. Studies are showing that significant changes occur in groups performing BFR with their rehabilitation versus similar groups that don’t. Many mechanistic models point to the hormonal changes occurring due to increased lactate accumulation and heightened muscle activity during exercises that typically would not elicit these changes.

Safety is a paramount consideration in any healthcare setting, especially in physical therapy. Compressing your limb with a tourniquet poses obvious safety concerns that must be taken into account. Interestingly, BFR has been studied at length over the last 5-10 years, and very few adverse effects have been found (as long as it’s applied correctly by a trained professional). There are devices specially-designed for BFR with exercise which utilize various safety features to reduce the risk of anoxic injury to a limb. Cuffs or straps which do not monitor blood flow or limb occlusion pressure can be dangerous and should never be considered, especially in the medical environment.

With a multitude of tools and seemingly endless bag of tricks, physical therapists are equipped to handle nearly any issue which limits one’s functional capacity. Recent technology has vastly improved how interventions can be applied, allowing patients greater means of recovery. BFR has shown significant promise in drastically improving rehabilitation potential for a variety of injuries and patients. By circumventing the body’s natural strength-building processes, we are able to achieve greater goals with far less risk.