Fascial Shearing and Rock Floss/Voodoo Floss

In recent times, “flossing” or “fascial shearing” has become a more popular treatment being used among physical therapists, athletes, and the fitness world in general. The treatment itself is relatively uncomplicated and done by wrapping a thin, latex, elastic band tightly around specific body parts to essentially “unstick” your muscles (with the warning of not putting it around your head or neck). Many patients and practitioners are applying it with the mindset of “it will just loosen you up better” without really knowing what the mechanism is behind the technique. Like many new treatments, research is limited on this subject matter and there are a few different theories explaining how it actually works. In reality, although the verdict is still out, we are finding positive results with the treatment. There are however, important aspects of the treatment that patients should know to better understand their body.

So let’s go through what we know, and start with terminology.

1) Fascia: a thin sheath of fibrous tissue enclosing a muscle or other organ. Fascia is the thin connective tissue that wraps around your muscles allowing them to “glide” or move on one another without just sticking together. People tend to think of fascia as this thin solid connective tissue that encapsulates the muscle and completely surrounds it when in fact it’s much more fluid. Here’s a video of the fluidity of fascia under a microscope and how elastic its properties are…(should be).

So now let’s introduce the problem: Lack of movement, injury, or overuse can cause adhesions in muscle tissue and fascia alike which will lead to dysfunction, pain, and restriction of movement.

What can be done!?

Along with many other soft tissue techniques, Rock Floss/Voodoo floss is here to save the day. The term fascial shearing is derived from applying a shear force to…you guessed it, the fascia. We believe when we wrap a muscle or body part tightly with this elastic band, we’re squeezing all those layers together. Then when we combine that with movement either weight-bearing or non weight-bearing, it’s creating a shear force to break up the adhesions better…So one theory states.

But this is not the only thing happening when you wrap a body part or muscle very tightly with a latex band. Then we have “vascular occlusion and hyperemia” which essentially means you are reducing blood flow to the area.  The compression on your body can significantly decrease blood flow to the area and when you remove the band, blood rushes back to the area which is thought to have multiple benefits. A few include: Increased blood flow to an injured area means increased oxygen, more nutrients getting to your cells, waste in your cells being flushed from the area.

The main reason this item and technique have become so popular is because people are finding real, subjective/objective results. Further research and evidence will be required to provide a clear, proper explanation of its mechanism but for now we will continue to use this soft tissue mobilization technique.


Phil Herel PT, DPT

Phillip Herel