published April 19, 2003
by Robert Schleip, in Journal of Bodywork and Movement Therapies (2003), online at www.somatics.de [excerpt]:
In myofascial manipulation an immediate tissue release is often felt under the working hand. This amazing feature has traditionally been attributed to mechanical properties of the connective tissue. Yet studies have shown that either much stronger forces or longer durations would be required for a permanent viscoelastic deformation of fascia. Fascia nevertheless is densely innervated by mechanoreceptors which are responsive to manual pressure. Stimulation of these sensory receptors has been shown to lead to a lowering of sympathetic tonus as well as a change in local tissue viscosity. Fascia and the autonomic nervous system appear to be intimately connected.
Stimulation of fascial mechanoreceptors can trigger viscosity changes in the ground substance. The discovery and implications of the existence of fascial smooth muscle cells are of special interest in relation to fibromyalgia, amongst other conditions. An attitudinal shift is suggested, from a mechanical body concept towards a cybernetic model, in which the practitioner’s intervention are seen as stimulation for self regulatory processes within the client’s organism.
Many of the current training schools which focus on myofascial treatment have been profoundly influenced by Ida Rolf. In her own work Rolf applied considerable manual or elbow pressure to fascial sheets in order to change their density and arrangement. Rolf’s own explanation was that connective tissue is a colloidal substance in which the ground substance can be influenced by the application of energy (heat or mechanical pressure) to change its aggregate form from a more dense ‘gel’ state to a more fluid ‘sol’ state. Typical examples of this are common gelatin or butter, which get softer by heating or mechanical pressure. This gel-to-sol transformation, also called thixotropy, has been positively confirmed to occur as a result of long-term mechanical stress applications to connective tissue.
But the question arises: is this model also useful to explain the immediate short-term plasticity of fascia? In other words, what actually happens when a myofascial practitioner claims to feel a ‘tissue release’ under the working hand? In most systems of myofascial manipulation, the duration of an individual ‘stroke’ or technique on a particular spot of tissue is between a few seconds and 1 1/2 minute. Rarely is a practitioner seen – or is it taught – to apply uninterrupted manual pressure for more than 2 minutes. Yet often the practitioners report feeling a palpable tissue release within a particular ‘stroke’. Such rapid – i.e. below 2 minutes – tissue transformation appears to be more difficult to explain with the thixotropy model. As will be shown later, studies on the subject of ‘time and force dependency’ of connective tissue plasticity (in terms of creep and stress relaxation) have shown that either much longer amounts of time or significantly more force are required for permanent deformation of dense connective tissues. Additionally the problem of reversibility arises: in colloidal substances the thixotropic effect lasts only as long as the pressure or heat is applied. Within minutes the substance returns to its original gel state – just think of the butter in the kitchen. This is definitely not an attractive implication of this model for the practitioner. …
Read the complete article at somatics.de/artikel/for-professionals/2-article/54-fascial-plasticity-a-new-neurobiological-explanation.