When Ida Rolf began putting her hands and elbows on people’s skin and applying pressure, creating a slow, sustained stretch, she imagined that she was stretching fascial sheets. Generations of manual therapists have followed her thinking, accepting this explanation to account for the changes felt in tissue tension beneath their hands and the sensations experienced by those who receive this type of therapy.
Ideas change over time
Much of manual therapy has grown largely out of anecdotal experience and tradition. Without the means to directly observe or measure what happened inside of the body, explanations for results had to be created from the “outside” and have largely been guesswork. As manual therapy has moved forward, an interest in understanding exactly how touch affects the body has led to a growing interest in research. With research has come the realization that many explanations of the past are not supported by evidence and are sometimes contradicted by evidence. Science-minded manual therapists have learned to adapt to this information, dropping outdated hypotheses and unsupported claims. While some have found it disconcerting to have cherished notions disproved, others have embraced knowledge and have adapted their conceptual models to fit what is known. They may continue to use modalities that have produced desired results but their understanding of how that comes about changes to fit the evidence.
Such a change is happening in the field of “fascial” therapy.
When Rolf began her groundbreaking work in manual therapy, she devised a hypothesis in an attempt to explain how changes created by her contact came about. However, in recent years, evidence has challenged those explanations. Robert Schleip, Ph.D., was one of the key organizers of the first Fascia Research Congress and is a highly respected researcher. He is credited with discovering minute contractile fibers in fascia, a discovery whose clinical relevance has not yet been demonstrated but still excited many in the world of fascial therapy just the same. In his two-part article, “Fascial Plasticity: a new neurobiological explanation,” published in 2003 in the Journal of Bodywork and Movement Therapies, Schleip points to studies which contradict the notion that we can change the shape of fascia with our hands. One study found that collagen fibers would only begin to stretch shortly before they reached the breaking point, something that would not be desirable in a living human being. In other studies, Schleip, Trager, and others have done Rolfing under anesthesia and found that it produced no results. If the application of manual pressure had the ability to stretch fascia, there should have been a change in spite of anesthesia blocking any neural response. Why, then, was there no change when anesthesia took the nervous system out of the picture?
A neurobiological explanation
If we aren’t stretching fascia, then how do we account for the “release” felt by both the practitioner and the subject? Schleip and others have suggested that the change in tonus is not achieved by an alteration in the shape of fascia but is instead controlled by the nervous system. Schleip suggests that one possible mechanism of change brought about by sustained manual pressure could be the Ruffini corpuscles.
Why Ruffini corpuscles? Clinically, we observe that applying a slow, extended stretch to the skin can create desirable changes both locally and centrally, decreasing tension in the area where the hands are applied as well as creating an overall sense of relaxation. Ruffini corpuscles respond to lateral skin stretch, that is, stretching the skin tangentially or along the same plane as the tissue below. They are slow-adapting, meaning that they continue firing for as long as the stretch is sustained, unlike some mechanoreceptors which respond briefly to new stimulation and then stop responding if it continues.
We know that when we apply our hands to the skin of the body, we stimulate mechanoreceptors. Impulses are sent through the sensory nerves to the brain. The brain evaluates and responds, sending out impulses of its own through nerves to various parts of the body, causing changes to occur in the diameter of blood vessels, breathing, muscle tonus. If it likes our touch, it can create the changes we associate with relaxation, release of tension, and can decrease the sensation of pain. If it feels threatened by our touch, it will do the opposite. As manual therapists, we are always trying to create changes that make the body feel at ease. We can achieve this through the nervous system.
The nervous system is constantly monitoring its environment, responding to a complex array of input. It would be naive and simplistic to think that response to our touch could be reduced to one set of mechanoreceptors or to ignore all the other countless factors. However, when examining the kind of manual therapy we have come to think of as "fascial," understanding the role of Ruffini corpuscles is a good place to start.
Why does it matter?
Does it matter whether we believe we are stretching fascia or not? It matters that we think accurate thoughts about how the body works and what effect our touch has on the body. Understanding how the body actually works will help us work more effectively.
We may still use our hands in ways that we have before. If those methods work to achieve the client's goal, there is no need to abandon them. However, we want to know that how we think about what we are doing is accurate and we want to be able to communicate honestly with our clients. If we discover that our conceptual model is contradicted by what is known about how the body works, then it is time to adapt our model so that our thinking is in agreement with evidence.
Manual therapists need not feel threatened by the news that we cannot stretch fascia. A growing number of Rolfers, practitioners of myofascial release, and related modalities are continuing to use their hands in the ways that have worked for them in the past while adapting their thinking to an updated neurobiological explanation. Many have found that this shift to thinking about the role of the nervous system in manual therapy has led to new, even more effective approaches.
A thought experiment
Schleip proposes an interesting thought experiment. During the time it took to read this article, one’s bottom, if seated, is subjected to more pressure over a longer period of time than most therapists will apply to the hips of a client. Yet most of us are not all stretched out and droopy from daily sitting for extended periods of time. Think about it.
Fascia Science, Stretching the Power of Manual Therapy by Greg Lehman, The Body Mechanic
Fascial Neurobiology: An explanation for possible manual therapy treatment effects by Greg Lehman, featuring guest post by Chris Beardsley
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