Voodoo Floss: (How) Does it Work?
***Disclaimer: I am not a Voodoo Expert (chiropractor, yes, but that’s another story). I am simply digesting out loud to stimulate my own thoughts on the matter. After having tried Voodoo Floss myself and seen great utility, I sadly found that no one online had taken a half-hearted jab at explaining how it might work. I do know a tiny bit of science and a tiny bit of logic. Here’s the story of what I currently debate in my head about this great product:
I’m not here to defend Voodoo Floss. I will be the first to admit that naming it “Voodoo” Floss was a great marketing ploy to entice lay-people into trying it out. However, throwing in a catchy name like that makes the skeptical clinician type (such as myself) more skeptical. 
But hey, I am often wrong. Quite frankly, I believe that allowing yourself to be wrong encourages long term personal growth and happiness. With that in mind, I personally learn the quickest in this process:
- Try it (creating an experience-based lens through which to view it)
- Read about it (look it at through other peoples’ lenses)
- Write about it (my form of mentally digesting it all of the above)
Knowing this, I decided to give Voodoo Floss a try. I’d figure out exactly what it does later…
How it works
Frankly, who knows. I think if it were well thought out, it might have never emerged, just like the story of Graston Technique, which thousands of clinicians now use and love. Somewhere along the line someone decided that they should tightly wrap an appendage with a rubber band, move around a bit, then take it off. And it felt better. Whoa. Let’s rack our brain for a few mile-high thoughts on what could be to blame for the obvious clinical improvements. As with nearly everything, you’ll note that I bring much of this back to the ol’ nervous system. How chiropracticy of me:
Fascial Shear
Time for a (simplified) Fascial Anatomy Lesson!
There are two thick “layers” of fascia. The layer associated with the skin is the Superficial Fascial Membrane. There is another layer which is very closely associated with muscle and skeleton, called the Deep Fascial Membrane. The deeper layer is not simply a “wrap” around muscles and soft tissues, but is also integrated within these structures to pass force and information in every direction.
The superficial fascia is attached to the dermis via “skin ligaments”, called the Retinaculum Cutis Superficialis (RCS). The superficial fascia is attached to the deep fascia via more soft tissue bridges, call the Retinaculum Cutis Profundus (RCP).
Simple Fascial Anatomy
(Click for enlarged version)
Fascial layers are densely populated with all sorts of receptors, most notably mechanoreceptors. In case you didn’t catch that, this means that fascia is like a loud-speaker to the brain, saying “Hey, something is moving down here in your less intelligent tissues. Howzabout you get involved, all up in here?”. Stack that with the fact that joint capsules (previously thought to be our main source of proprioception) are considered to provide strong feedback only during end range stretch/compression, I think we can safely assume that fascia is a key component in neurological feedback loops, especially related to movement.
So, how does this apply to Voodoo Floss? It’s simple really. The strong elastic compression will quickly alter fascia’s relation to all other aspects of the neuromusculoskeletal system when you move with it on. It would likely take some tension out of certain areas of the fascia, shifting it to other areas via strong intra-sling/intra-layer tension redistribution and inter-layer shear. It’s all about the tensegrity, baby. So what does this mean? I get a hunch that it can massively alter neural input by making a quick change in the mechanical transmission of the fascial system (and it’s many mechanoreceptors) when moving underneath some strong compression and stretchy-pulley forces. That’s the technical term.
It comes down to relative tissue motion. Listen in to Dr Andreo Spina talk a bit about this concept in this video about soft-tissue release and foam rolling. Compression +Tension + Movement = Fibrosis release. Sounds suspiciously familiar…
The Takeaway: looking at Voodoo Floss simply as a compression mechanism is quite simplistic, since the vast majority of users will wrap themselves up and move.
However, based on a model of neurological feedback and fibrosis release via inter-layer and intra-layer fascial shear, respectively, I would suggest that users dawn their floss and move through as large of a range of motion as possible in as many planes and directions as possible in order to ascertain the maximum amount of beneficial effect.
Occlusion and Reactive Hyperemia
I realize that one is not “suppose to” use Voodoo Floss to occlude blood flow. What one should do and what one does are often different. Besides, short term ischemia of a skeletal muscle is not always a bad thing (see here ). I think it odd that most trainers say that you should not go so tight as to occlude blood flow, when K-Star himself cites it as one of the benefits at around 3:00 of this video.
Based in this study, one could potentially see these sorts of benefits from as little as 15 seconds of blood flow restriction. Looking here and here, we see that primary hormonal vasodilators, prostoglandins and nitric oxide lead to hyperaemia following restriction of blood flow. I don’t know this, but I would assume that increased blood flow to an area would help with hydration, healing, and performance.
As another interesting thought, I came across a study indicating that low intensity exercise with occlusive stimuli stimulates muscular strength and size (in 8 weeks, compared to exercise with no occlusion), as well as an acute spike in Human Growth Hormone within 15 minutes.
- Nitric Oxide + Growth Hormone = Ronnie Coleman.
The Takeaway: There is a beneficial local endocrine response to temporary occlusion, resulting in increased H.G.H. and N.O., two messengers that could potentially lead to improved healing times, among other things.
Temporary, Artificial Joint Centration
Voodoo Floss is sometimes applied mid muscle belly, but I see it applied around a joint more often. The first time I used it on my knee following knee surgery about 6 months ago, I couldn’t get over the instant improvement in range of motion within about 10 seconds of putting it on. Using the extremely rough estimate of pain-free knee-to-butt ROM, I went from about 10 inches to within 4 inches in a matter of seconds. I realize that the knee is not the kind of joint that one would typically classify as optimally centrated in the sense that it does not have a particularly spherical joint surface. However, it does have an optimal I.A.R. (instantaneous axis of rotation) at any given angle and in any plane. What if we gave it a mechanical centration-assist that was able to stretch and move as needed? I would think that pain-free ROM would increase through optimal motor control. In the FMS or SFMA world, we could call this a pattern-assist.
The nice thing was that I wore the Voodoo Floss for about 30-45 seconds, did some passive knee flexion, some lunges on a box with assisted tibial IR, a few squats, then took it off. Budaboom. Instant squat improvement.
I have seen this work extremely well in the femoroacetabular joint, the tibiofemoral joint, the ankle mortice, as well as the glenohumeral joint. I am sure it works well elsewhere, too. We wrap up the joint, go through some active and passive movements, both compound and single joint, then remove. There is generally a quick carryover into motor control and pain free ROM. In the past, almost anything I have seen which makes such a quick improvement in mobility can be attributed to motor control, not some physical property change. AND, since optimal feedback will be occurring from optimal joint centration, I am going to take this one step further and suggest that maybe we are giving ourselves some artificial joint centration by tightly wrapping a joint and all of it’s soft tissues.
The Takeaway: Voodoo Floss could be acting as a “Pattern Assist” via artificial joint centration, followed by active movement.
Skin Strain: Pain Gating and Kinaesthetic Sense
Instead of writing all about this one, let me quote a book I am laboriously attenmpting to finish off right now, called Pain: It’s Anatomy, Physiology and Treatment by Aage R. Moller:
(Referring to input from larger, myelinated sensory fibers) This input from the periphery is inhibitory and it can modulate the transmission of pain signals. It is a part of the gating of pain signals described by Melzack and Wall (1965). The so-called “intermediate zone”, consisting of cells of laminae VI, VII, and VIII, has cells that receive input from large diameter fibres (mainly A-beta fibers) that innervate receptors that respond to innocuous a nocuous (painful) stimulations from large areas of skin.
For anyone who has tried Voodoo Floss, they know that the stimulation of the skin is probably the strongest sensation that one feels during “flossing”. I assume I don’t have to explain this much further, considering the previous quote.
Here’s one you may not have thought of, as it pertains to skin strain:
It is concluded that (i)the brain’s assessment of the position at finger joints maybe determined by afferent signals generated as a result of movement-associated skin strain patterns, (ii) afferent signals originating in skin mechanoreceptors under certain circumstances have precedence over signals generated in mechanoreceptive muscle afferents with respect to the perception of movements and the control of motor behaviour, and (iii) skin strain may be perceived as joint movements rather than skin deformation.
That’s a direct quote from one of many studies which have shown that skin strain gives strong kinaesthetic information to the CNS. This one can be found here, if you wanted to read the whole article, as I did.
The Takeaway: Don’t rule out the skin as a major player in the nervous system. That skin strain you feel during flossing is a strong kinaesthetic input to the CNS, potentially improving movement, as well as gating pain.
An Inconclusinve Conclusion
As you may have guessed, what I’ve outline here is likely not exhaustive. I have dozens of other theories about how Voodoo Floss might work. Some of those theories are related to nerve flossing/tension, compartmental pressurization, tissue hydration, psychological effects, etc. This article is borderline too long already, so I will leave you, the faithful reader, to come to your own conclusions on those fronts.
What are your thoughts and experiences with Voodoo Floss?
