The purpose of this article is to share perspectives for the clinician from the recent Second International Fascia Research Congress. Interested readers are referred to the DVD and books from both the first and the second congresses, available for purchase at:

<a href=’http://www.fasciacongress.org/dvd-book-purchase.htm’ target=’_blank’>http://www.fasciacongress.org/dvd-book-purchase.htm</a>

My editorials in the <i>International Journal of Therapeutic Massage and Bodywork</i> are available online at no charge. The June 2009 editorial provides an introduction to the fascia 2007 program book:

<a href=’http://www.ijtmb.org/index.php/ijtmb/article/view/52/63′ target=’_blank’>http://www.ijtmb.org/index.php/ijtmb/article/view/52/63</a>

Similarly the October editorial introduces the 2009 book:

<a href=’http://www.ijtmb.org/index.php/ijtmb/article/view/61/70′ target=’_blank’>http://www.ijtmb.org/index.php/ijtmb/article/view/61/70</a>

What follows are some key points designed to whet your appetite for more. Readers are encouraged to obtain the books and/or DVD?s, and come prepared with questions at the IASI meeting in May 2010. I encourage you to submit your questions by email in advance. Please send to [email protected], and indicate the congress year, DVD/book, and presenter associated with your question?e.g., 2007 DVD Ingber or 2009 Book Vanderwal?in your email subject line. Questions received before April 15 will be incorporated into my presentation. (Examples questions are provided at the end of this article.)

<center>Fascial Anatomy</center>

Anatomical thinking has been limited by the traditional dissection process, in which connective tissue is removed to display underlying tissues. Connective tissue is usually named based on the nearby structures, suggesting little role for this tissue as such. From the structural viewpoint however, connective tissue can be seen to have two distinct functions: to separate or allow gliding, or to connect and transfer forces. The same principles can be seen in the connective tissue of the abdomen as in the tissue of the extremities. The ?separating? function of connective tissue is most evident in the connections between a tendon and the tendon sheath, which allows for a great deal of excursion. Readers interested in pictures at surgery of this loose connective tissue and in a theoretical framework for a structure that remains under relatively constant load throughout a wide range of displacement are directed to the work by the Fascia 2007 speaker hand surgeon Guimberteau, both in video (1) and in papers (2, 3).

Muscles and ligaments cannot be viewed as separate structures next to each other, each acting independently to handle mechanical stresses across a joint. Because ligaments can bear stress only when they are stretched fairly tight, ligaments can serve to stabilize joints only if the distance between the bones on each side of the joint remains fairly constant throughout the joint range of motion; this condition exists in only two joints in the body. At all other joints there are specialized connective tissue structures running between the muscles and the bone of origin or insertion. This dynamic connection between connective tissue and muscle provides a structural support that can adapt to changing distances between bones throughout the joint range of motion. Some muscles have these specialized connective tissue structures at the proximal end only, some at the distal end only, some at both ends?and some at neither end. Furthermore, analysis of mechanical force transfer through such structures shows that nerve endings are concentrated where the stresses are the highest. The full text of VanderWal?s important paper is online at:

<a href=’http://www.ijtmb.org/index.php/ijtmb/article/view/62/79′ target=’_blank’>http://www.ijtmb.org/index.php/ijtmb/article/view/62/79</a>

<center>Fascial Biomechanics and Physiology</center>

Within a muscle fiber, up to half of the total force generated by the muscle is transmitted to surrounding connective tissues rather than directly to the origin and insertion of the muscle fibers. Force can be transmitted to adjacent muscles that are synergistic, as well as to extramuscular tissues such as the neurovascular tract and various septa and membranes; by this extramuscular pathway, such forces can reach antagonistic muscles. And so the findings that synergistic muscles are not mechanically independent seem to also apply to antagonistic muscles. These findings have implications for the management of muscle conditions found in people with spastic paresis, who often find themselves with joints fixed in a particular position?for example, wrist flexion or ankle plantar flexion. Immobilization of a highly pennate muscle results in atrophy if the muscle is in the shortened position, but if the muscle at immobilization is in a lengthened position, it may even result in hypertrophy. In any particular joint position, some of the sarcomeres in a given muscle may be shortened, and others may be lengthened, because of the local connective tissue connections with other muscles. The analysis of the impact on a given muscle therefore becomes quite complex.

<center>Fascial Cytology and Histology</center>

Ingber, one of the key speakers from the 2007 Fascia Congress, introduced the concept that ?cells act locally but think globally? in sensing tensional forces in the extracellular matrix (ECM). Integrin receptors on the cell surface are mechanically coupled to the actin cytoskeleton of the cell, forming a pathway to sense external forces and allow the cell to respond with changes in cell shape. Cells can activate internal chemical signaling pathways, increase stress-fiber assembly and adhesive strength, and form focal adhesions in response to externally applied mechanical forces. Ordinarily this mechanism is damped to lower the sensitivity of this mechanism to normal physiologic fluctuations. However, once a largescale change occurs in the ECM, altering the cell shape, that cell then becomes more responsive to its immediate mechanical domain.

Grinnell demonstrated that cells adhere to matrix fibrils specifically, rather than to nonspecific matrix proteins, and that cells can remodel these matrix fibrils or can penetrate into the matrix. These interactions are controlled by the tension between cell and matrix, which in turn depends on collagen density, growth factor, and matrix restraint. Grinnell finds that cells under high tension show stress fibers, focal adhesions, and enzymatic activation related to the adhesions. At low tension, cells lack these features and assume a different morphology, resembling dendritic cells. These cells resemble the mechanoreceptor osteocytes in bone, and the formation by soft-tissue fibroblasts of a mechanosensing network can be hypothesized.

Physiologists have known for a long time that blood flow to tissues rapidly increases when muscles contract. This supports the increased metabolic demands of the tissues, but the precise local mechanism has been unclear. Hocking demonstrated mechanical coupling of skeletal muscle contraction with local arterioles. Actively contracting skeletal muscle generates tensile forces that change the conformation of ECM fibronectin fibers surrounding the arteriolar wall. This change briefly exposes a heparin binding area of the fiber, which initiates smooth muscle relaxation and hence vasodilation.

<center>Fascial Cytology and Mechanics</center>

Many therapeutic techniques are based on the stretching of connective tissues, but whether that stretching is greater than the stretching applied in daily life, or whether it is of a normal range applied to tissues that have themselves been subjected to less-than-normal stresses is not known. Iatridis and colleagues found a very low, but linear, viscoelastic biomechanical response to applied stress in subcutaneous tissues. The tensile modulus is similar to levels reported by others for the pericellular matrix of the cell, articular chondrocytes, skin, and the nucleus pulposus, and about 1/400,000 that of the medial collateral ligament. This tissue has a much lower tensile elastic modulus and relaxes faster than do most other tissues, suggesting that it is already bearing load even at the lowest strain levels. Iatridis interprets this finding as indicating that, rather than having a load-bearing function, loose connective tissue serves to transmit mechanical signals.

Purslow hypothesizes that, as muscles change shape during contraction, the connective tissue layers allow these tissues to slide past each other with a controlled amount of resistance. He also notes that the very thick outer layer of fascia that divides muscles into different compartments (for example, the anterior compartment of the lower leg) is usually seen by physicians only as a source of trouble when the pressure rises too high, creating a ?compartment syndrome? which becomes a surgical emergency. However, in normal activity, contraction of one muscle within the compartment results in a small elevation of pressure, which increases contractile efficiency of the other muscles contained within that compartment. These normal pressure changes result in cyclical changes throughout the gait cycle, which assists in venous return of blood to the heart with the calf muscles serving as a ?second heart pump? (4, 5) and assisting with perfusion to the muscle itself. (6) Furthermore, the arteriolar dilation with muscle contraction previously noted may further contribute to this muscle pumping mechanism.

<center>Functional Innervation</center>

A fascial tissue of particular interest is the connective tissue envelope around nerve tissues. Of particular interest are the fascial envelopes of peripheral nerve fascicles (perineurium, which maintains the so-called blood-nerve barrier) as well as the much thicker layer surrounding whole peripheral nerves with their blood supply (epineurium). Bove, one of the key speakers from the 2007 Fascia Congress, gives an excellent review of the current understanding of their important contributions for pain regulation. He provides evidence that these two fascial layers are themselves innervated by ?nervi nervorum? which can evoke nociception and are likely responsible for nerve trunk pain. They can also evoke neurogenic inflammation. While normal nerves are not mechanically sensitive, an inflammatory reaction of their fascial envelopes may induce mechanical sensitivity, which can express either as local pain or as radicular pain, such as is often utilized in the diagnostic straight leg maneuver.

The extensive animal studies of Magnus & de Kleijn (7)?published already in 1912?had indicated the existence of postural and motor reflexes induced by small changes in head positioning. Specifically a nose-down orientation leads to increased muscle activation in the hind limbs, whereas a nose-up position triggered activity in the forelimbs. Many contemporary movement education and rehabilitation programs utilize ?symmetric tonic neck reflexes? based on these observations.

Gottschall and Nichols conclude that sensory feedback related to head positioning significantly influences postural control. In particular they suggest that neck proprioceptors and/or the vestibular organ are responsible for the initiation of appropriate muscle activation patterns during walking. In respect to motor rehabilitation programs they recommend that their findings can lead to specific training applications. A tilting of the head upwards for example tends to cause a decrease in leg muscle activity. This could therefore be used with Parkinson patients who have difficulty ceasing movement. On the other hand a tilting of the head down could be used as a helpful addition to initiate locomotor movement in patients with incomplete spinal cord injuries, as this tends to increase leg muscle activity.

<center>Low Back Pain and Lumbar Fascia</center>

One of the highlights of this congress?and probably one of the most promising topics in musculoskeletal research in the next few years?is the investigation of the role of the human lumbar fascia in low back pain. Although the pain generative role of spinal disc damage is undisputed for some cases of low back pain, they do not seem to play a decisive role in the majority of cases in this very common pathology. Comparisons of lumbar spine MRI between back pain patients and normal patience reveal, that many people without back pain show severe disc damage as well, and many back pain patients on the other side show significantly better discs than comparable pain-free people of the same age group. (8) Recently new explanatory models for the generation of low back pain have been developed, which point to a potential pain generating role of paraspinal fascial tissues.

It is therefore of particular interest that the human lumbar fascia seems to be play an important role in low back stability of humans. Barker finds that simulated moderate contraction of transversus abdominis exerts tension onto the lumbar fascia and influences segmental stiffness. The majority of tension is transmitted via the middle layer of the lumbar fascia (which attaches to the lumbar transverse processes and covers the quadratus lumborum posteriorly). This tension transmission effect of lumbar fasciae is most marked towards the neutral zone, i.e. where segmental control is of greatest clinical importance.

<center>Molecular Biology and Cytology</center>

Standley developed a cellular model of repetitive strain injury and manual medicine treatments. He expanded his experimental paradigm to look at acyclical strain in human fibroblasts in a two-dimensional tissue culture matrix, as a first step in modelling osteopathic manipulative treatment at the cellular level. (9) To model repetitive strain, he subjected cells for eight hours to a constant base level of 10% strain, which increased to 16.6% briefly every 1.6 seconds (experimental details in 10). After a three-hour rest, some of the cells were subjected to a single sixty-second static release of strain (designed to simulate indirect osteopathic manipulative techniques). Pro-inflammatory interleukins were secreted and cell proliferation reduced twenty-four hours later in those cells exposed to just the repetitive strain, and these effects were largely counteracted by the sixty-second treatment. Photomicrographs show the effects of these treatments on fibroblast morphology and architecture of actin stress fibers. A key factor is strain which is uni- rather than multi-axial, as strain which is equal in all directions does not seem to impact cell morphology, inflammatory interleukin secretion, or cell proliferation (experimental details in 11).

<center>Pathology and Treatment</center>

Collagen fibrils in the skin vary depending on its mechanical role, and remodel in response to mechanical stress and during wound healing. Edsberg has shown that collagen bundles in the human foreskin remodelled with pressure, with static forces resulting in fibers parallel to the surface and dynamic forces resulting in those perpendicular to the surface. (12) She also found there was a greater decrease in stiffness the greater the static pressure. (13) Edsberg looks at the long term effects of pressure at those areas immediately adjacent to pressure sores in humans, areas which have been subjected to chronic elevated pressures. She found the pressure ulcer samples to have 1/3 the number of straight and ½ the number of wavy collagen fibers compared to normal tissue from breast and leg, with individual fibers 50% longer and wider in the pressure ulcer group. She concludes, ?These long-term [microstructural] changes were so severe that tensile testing did not further alter the damaged tissue microstructure? and suggests that these changes may be precursors to the development of the actual sore.

Measuring effects of treatments can either focus on overall outcomes or on more specific intermediate physiological mechanisms by which such treatments are thought to work. Suter takes an important step in documenting changes in spinal cord neurophysiology after spinal manipulation. Direct electrical stimulation of a peripheral motor nerve evokes discharge of the muscle spindle Ia afferents, which synapse directly with the motor neuron in the spinal cord and result in a measurable muscle twitch, analogous to the deep tendon reflex, which is called the H reflex. These reflexes can be altered in persons with acute or chronic low back pain, and can be influenced by manual treatments including cervical traction, massage, manipulation, and vibration. H reflex response can be facilitated by mild contraction of the agonist or distant muscles such as the jaw(14) and decreased by mild contraction of the antagonist muscles ; these effects are seen in the premotor phase (100 to 200 msec) before the muscle contraction actually starts?in fact, merely thinking about moving agonist or antagonist muscles has a demonstrable effect on the H reflex.(15) This suggests that rather than being a movement artefact, changes seen after the patient changes position may be predictable consequences of small changes in motor activation of agonist and antagonist muscles. It also points to the importance of taking into account both physical and neurophysiological interconnectedness of muscles in treatment studies.

Experimentation has established that the traditional length-force characteristics of muscles are not basic properties of an individual isolated muscle but depend on an intact surrounding with connections to other muscles and tissues. Furthermore, these are not a fixed property for a given muscle but vary as the surroundings change. It has become clear that there are substantial differences in measured forces at the origin and insertion of muscles, which provides strong evidence for transmission of force in a pathway external to the traditional myotendinous path. Additional support comes from prestrain in the epimuscular connections, which provides the necessary stiffness for force transmission. Within a given muscle fiber, consisting of multiple sarcomeres arranged in series, there is considerable variation in individual sarcomere length; modelling suggests that under some conditions distal sarcomeres may actually lengthen while more proximal ones shorten.

<center>Communications about Fascia</center>

Whereas the academic field of ‘connective tissue research’ has shifted its main focus mostly to molecular dynamics (with particular attention to bone dynamics, cartilage, and genetic analysis), the newly emerging field of fascia research pays particular attention to aspects in which the body’s collagenous soft connective tissues work together as a body-wide three-dimensional fibrous network for support. Huijing and Langevin propose a further recommendation for describing fascial tissues with more specification. Depending on its morphology and arrangement they suggest criteria by which a local tissue can be correctly described as ‘superficial fascia’, ‘deep fascia’, ‘epimysium’, etc. The inclusion of such specified descriptions can be extremely helpful in understanding differences in the tissue’s structural function. This important paper is also available online:

<a href=’http://www.ijtmb.org/index.php/ijtmb/article/view/63/80′ target=’_blank’>http://www.ijtmb.org/index.php/ijtmb/article/view/63/80</a>

<center>Asking the Right Question</center>

No question is too simple, or not relevant, or too complex. Furthermore, you can be assured that there are a hundred other people with the same question that you have, they just were afraid to speak up. So please, ask away. I will list here a few questions of my own, to give examples. Most of these do not have answers (yet) but can guide both future research and the development of new teaching or treatment techniques.

? 2009 book Coppetiers (2.1.1) How does manual therapy affect the excursion of nerves? And are there some body positions or body motions during therapy, which might increase this effect?

? 2009 book Vanderwal (2.1.2) If the nerve receptors are concentrated in parts of the muscle/connective tissue complex where forces are transmitted, will this change if the loading of the tissues changes? What are the benefits of concentrating our manual therapies on these force transmission / receptor zones?

? 2009 book Huijing (3.1.1) What are the implications of force transmission between agonist and antagonist muscles for structural integration in children with cerebral palsy? How can the results of Perry et al be explained with these mechanisms?

? 2009 book Edsberg (9.1.1) I have read this over several times. I do not understand what meaning this has for the practice of manual therapies.

? 2009 book Suter (9.1.2) What is the H reflex? Why should I know something about it and how might this affect the treatment I give?

So pick one or two papers or talks, read them or listen to them several times, and ask some questions. I do NOT expect you to wade through the entire materials presented at the two fascia congresses (although I myself will). However, if each of you picks one or two of the authors, most of them will then have questions asked, and I will be able to answer questions about clinical relevance for most of the work. I have both an active clinical practice (twenty clients a week) and a 25-hour research position, which will help me to answer your questions. However, for exactly the same reason, I cannot ASK all the questions which you might have. And, like any good practitioner, I too have those moments when I wonder if I really know what is going on or whether am I indeed doing anything. But I do trust in the wisdom of Dr. Rolf, and am constantly impressed by the structure she has developed and passed on to her students. It is almost as if she foresaw the Fascia Research Congress as the next logical extension of her work.

Notes

1. Guimberteau JC. Strolling Under the Skin. Pessac, France: ADF Video Productions; 2003.

2. Guimberteau JC, Sentucq-Rigall J, Panconi B, Boileau R, Mouton P, Bakhach J. [Introduction to the knowledge of subcutaneous sliding system in humans]. Ann Chir Plast Esthet. 2005;50(1):19-34.

3. Guimberteau JC, Bakhach J, Panconi B, Rouzaud S. A fresh look at vascularized flexor tendon transfers: concept, technical aspects and results. J Plast Reconstr Aesthet Surg. 2007;60(7):793-810.

4. Casey DP, Hart EC. Cardiovascular function in humans during exercise: role of the muscle pump. J Physiol (Lond). 2008;586(Pt 21):5045-5046.

5. Panny M, Ammer K, Kundi M, Katzenschlager R, Hirschl M. Severity of chronic venous disorders and its relationship to the calf muscle pump. Vasa. 2009;38(2):171-176.

6. Nadland IH, Walloe L, Toska K. Effect of the leg muscle pump on the rise in muscle perfusion during muscle work in humans. Eur J Appl Physiol. 2009;105(6):829-841.

7. Magnus R, A dK. Die Abhängigkeit des Tonus der Extremitätenmuskeln von der Kopfstellung. Pflugers Archiv. 1912;145:455-548.

8. Jensen MC, Brant-Zawadzki MN, Obuchowski N, Modic MT, Malkasian D, Ross JS. Magnetic resonance imaging of the lumbar spine in people without back pain. N Engl J Med. 1994;331(2):69-73.

9. Dodd JG, Good MM, Nguyen TL, Grigg AI, Batia LM, Standley PR. In vitro biophysical strain model for understanding mechanisms of osteopathic manipulative treatment. J Am Osteopath Assoc. 2006;106(3):157-166.

10. Meltzer KR, Standley PR. Modeled repetitive motion strain and indirect osteopathic manipulative techniques in regulation of human fibroblast proliferation and interleukin secretion. J Am Osteopath Assoc. 2007;107(12):527-536.

11. Eagan TS, Meltzer KR, Standley PR. Importance of strain direction in regulating human fibroblast proliferation and cytokine secretion: a useful in vitro model for soft tissue injury and manual medicine treatments. J Manipulative Physiol Ther. 2007;30(8):584-592.

12. Edsberg LE, Natiella JR, Baier RE, Earle J. Microstructural characteristics of human skin subjected to static versus cyclic pressures. J Rehabil Res Dev. 2001;38(5):477-486.

13. Edsberg LE, Mates RE, Baier RE, Lauren M. Mechanical characteristics of human skin subjected to static versus cyclic normal pressures. J Rehabil Res Dev. 1999;36(2):133-141.

14. Takahashi T, Ueno T, Ohyama T. Modulation of H reflexes in the forearm during voluntary teeth clenching in humans. Eur J Appl Physiol. 2003;90(5-6):651-653.

15. Ikai T, Findley TW, Izumi S, Hanayama K, Kim H, Daum MC, et al. Reciprocal inhibition in the forearm during voluntary contraction and thinking about movement. Electromyogr Clin Neurophysiol. 1996;36(5):295-304.