Fascinating Fascia

For about 10 years now, the anatomical structure known as fascia has been on everyone’s lips. Fascia rollers, fascia balls, fascia massage, fascia distortion model (FDM), fascia yoga, etc… but what exactly is this fascia anyway?

Fascia is a connective tissue matrix that envelops all of our body structures (muscles, ligaments and joints, bones, nerves, blood vessels, and organs) like packaging. As a result, fascia gives us our shape (body) and serves as the primary protective layer against external forces.

Frank Liebig creator QS:P170,Q29586018, Spinnennetz in Tannenspitze, CC BY-SA 3.0 DE

Structure of Fascia

The body fascia can be divided into four different layers. The outermost layer directly under the skin forms the panniculus fascia, often referred to as the superficial fascia. The panniculus fascia consists mostly of loose connective tissue and fat and covers our entire body (trunk, arms, and legs) with the exception of body openings such as the mouth, eyes, nose, etc.

The second layer is formed by the trunk fascia (deep fascia or muscle fascia). Just like the panniculus, the trunk fascia develops from the embryonic mesenchyme. It forms the primitive matrix in which all skeletal muscles, bones, tendons, ligaments, and joints originate during embryonic development. In the arms and legs, the trunk fascia is usually referred to as muscle fascia – however, the function remains the same: the dense, mesh-like connective tissue serves as a protective and sliding layer for the musculoskeletal system and transmits part of the force to the joints during muscle contraction.

The third and fourth fascia layers are enclosed by the trunk fascia and are referred to as the meningeal and visceral fascia. The meningeal fascia encloses and protects our nervous system, while the visceral fascia acts as protection and suspension for our internal organs. 

It is important to note that these four layers should not be viewed as individual systems, but rather as a unified continuum of tissue structures.

The body's fasciae, just like key joint capsules and intramuscular and intraneural septa, belong to the unformed (mesh-like), dense connective and supportive tissue of our body. Tendons and ligaments, on the other hand, consist of formed (parallel-fibered) connective tissue. The difference lies in the arrangement of the collagen fibers in the tissue – in response to tension acting in different directions, the collagen fibers in the unformed, dense connective tissue form networks that can also shift and unfold in different directions. In formed connective tissue, all fibers are always aligned in the same direction – they run parallel to one another due to the constant, uniform strain. Therefore, fascia is much more flexible and mobile compared to ligaments.

Fundamentally, unformed and formed connective tissue consist of the same building blocks – cells and extracellular matrix. The cells are divided into fibroblasts/fibrocytes, chondroblasts/chondrocytes, and osteoblasts/osteocytes. The type of tissue into which the connective tissue develops depends on the mechanical demands exerted on the tissue or mesenchymal cells.

If tensile forces predominantly act on the tissue, fibroblasts will mostly develop, which in turn produce mainly type I collagen fibers and very little elastic ground substance – meaning tendons and ligaments develop. However, if pressure predominantly acts on the tissue, chondroblasts will mostly develop, which produce exclusively ground substance and only very thin type II collagen fibrils. This is basically found in hyaline articular cartilage.

In fascial tissue, it is mainly fibroblasts that develop. However, these contribute only a small part to the volume of the fascia, but they do play an important role in the assembly/structure as well as in fascial stiffness. The tasks of the fibroblasts are to produce most of the components that make up the extracellular matrix – with the exception of the abundant water in the fascia – as well as to repair tissue injuries during wound healing.

In addition to fibroblasts, adipocytes (fat cells) are also found in fascial tissue. Adipocytes not only play an important role in estrogen production, but are also key producers of various peptides and cytokines responsible for appetite, insulin, and blood sugar regulation, as well as for angiogenesis (growth of blood vessels), vasoconstriction (vascular narrowing), and blood clotting – crucial substances during wound healing. In the fascia, adipocytes are densest and most numerous in areas with high shear forces and sliding movements, where they serve as cushioning.

Studies have shown that there are many different types of receptors within the fascia. These include myelinated proprioceptive endings as well as a large number of unmyelinated "free" nerve endings. These nerve endings provide essential signals for the control of movement and posture (proprioception) to our brain, where conscious and unconscious perception of posture and movement is formed using information from other sources in our body. When you look at the number of receptors in fascial tissue, it is easily as large as, if not larger than, the number of receptors in the retina of the eye. You can easily imagine that the fascia is one of our most important sensory organs!

An effective overview of the structure and function of the fascia was provided by French hand surgeon Dr. Jean-Claude Guimberteau. Intraoperatively, he used an endoscope to examine how the fibers of the fascia move and behave. In his film "Strolling under the skin," you get a wonderful glimpse under the skin.

"PROMENADES SOUS LA PEAU OU A la découverte des architectures de la matière vivante", Dr. Jean-Claude Guimberteau

Role & Function of Fascia

 In addition to serving as a sensory organ, the fascia must be able to deform very quickly in different directions and planes and instantly return to its original shape – because the fascia acts as the primary shield against external impacts. Our muscles, bones, and joints generally cannot withstand too much direct contact without sustaining damage. To prevent muscle injuries (e.g., muscle fiber tears) in particular, the fascia must act immediately as a shock absorber during large, rapid impacts, as the muscles themselves react too slowly to prevent injury.

One-sided, one-dimensional movements can lead to adhesions in the fascia. These are known as crosslinks. As a result, the fascia loses some of its glidability. Consequently, as in the scenario mentioned above, the fascia can no longer absorb the full impact of the force, which can lead to a muscle tear.

In addition to its function as a protective sleeve, the fascia, due to its layered arrangement, serves as a sliding and shifting layer. You can think of it as individual nerves, arteries, veins, muscles, and even muscle groups being enveloped and separated from one another by a fascia. The fascia thus enables movement between the individual structures in our body.

Furthermore, this architecture of the fascia supports the muscles in transmitting force between muscles, muscle groups, and joints during movement and exercise – working in what are known as myofascial chains. These chains are named differently by different authors, but they all have one thing in common: every muscle group needs a foundation to perform its function. This foundation consists of other muscle groups, which in turn are stabilized by further muscle groups, etc. Certain therapies, such as Proprioceptive Neuromuscular Facilitation (PNF) by Dr. Herman Kabat, are based on the theory of myofascial chains. This is a method for treating muscle paralysis in polio, where the idea is that paralyzed muscles are activated in coordination with/through other muscle chains.

Therapy

Why is fascial treatment so important and efficient? Picture the fascial system as four layers of stockings worn on top of each other, with nerves, blood vessels, and lymphatic vessels grown into them. To allow movement, these four stockings must be able to slide freely against each other in all directions. If there are crosslinks between the layers, this not only limits mobility, but also directly affects the nervous, blood, and lymphatic systems.

Now, if you use your hand to pull the stocking tighter at the calf – as is the case, for example, with scar formation after surgery in the fascial tissue – you can easily observe how far up the stocking is put on stretch. That is why it is not surprising that if you have an injury/restriction/scar, it can cause problems across other joints in an entirely different part of the body.

When experiencing pain or movement restrictions, the goal for a physiotherapist and osteopath is to identify which structure holds the blockage – this reduced mobility – in order to apply a customized technique so that the restrictions and pain are positively influenced, allowing the tissue to return to its healthy state.

New research seems to prove that fascia can contract and plays an important role in force development and transmission [1,2]. In addition, together with muscles, tendons, and joints, they serve as an absorption mechanism for rapid-acting forces. From our perspective, fascia must therefore be viewed and treated in the overall context of the muscles. Based on the symptoms, the focus of training and therapy can be placed on specific structures; however, as mentioned, these are highly interconnected so the entire body is always being trained. Manual therapeutic measures for treating fascial and muscular problems include fascia/connective tissue massage, myofascial release, FDM, trigger point and dry needling therapy, PNF, stretching, fascia rolling, etc.

Training Fascia

Fascia can and should be trained together with the entire musculoskeletal system to ensure mobility and functionality. However, in our opinion, the anatomy and function make it very difficult to train the fascia alone: you are training the entire neuro-muscular system. The key, however, is to work in all dimensions and not just perform one-sided movements. Workouts like Pilates and Yoga are highly recommended, but jump movements, such as jumping rope, are also incredibly helpful. High Intensity Interval Training (HIIT) is also great for fascial training methods. With HIIT, however, the joints are under more stress than with Yoga and Pilates, which is why we recommend this form of training with the support of a physiotherapist or personal trainer – meaning under expert guidance.

" Faszien - Geheimnisvolle Welt unter der Haut", all rights reserved by arte.tv

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References

[1] Fascial tissue research in sports medicine: from molecules to tissue adaptation, injury and diagnostics: consensus statement

Zügel M,Maganaris CN, Wilke J, et al.

Br J Sports Med 2018;52:1497.

[2] Are muscles mechanically independent?

Robert D. Herbert, Phu D. Hoang, and Simon C. Gandevia

J Appl Physiol 104: 1549–1550, 2008; doi:10.1152/japplphysiol.90511.2008.

Title Image Credits

anonymous, Kreuzspinne, Netz im Gegenlicht, marked as public domain, details on Wikimedia Commons