The knowledge of fascial structures is essential in surgery, as they create borders for infectious processes (for example Psoas abscess) and haematoma. An increase in pressure may result in a compartment syndrome, where a prompt fasciotomy may be necessary. For this reason, profound descriptions of fascial structures are available in anatomical literature from the 19th century.
Function
Fasciae were traditionally thought of as passive structures that transmit mechanical tension generated by muscular activities or external forces throughout the body. An important function of muscle fasciae is to reduce friction of muscular force. In doing so, fasciae provide a supportive and movable wrapping for nerves and blood vessels as they pass through and between muscles.[4]
In the tradition of medical dissections it has been common practice to carefully clean muscles and other organs from their surrounding fasciae in order to study their detailed topography and function. However, this practice tends to ignore that many muscle fibers insert into their fascial envelopes and that the function of many organs is significantly altered when their related fasciae are removed.[5] This insight contributed to several modern biomechanical concepts of the human body, in which fascial tissues take over important stabilizing and connecting functions, by distributing tensional forces across several joints in a network-like manner similar to the architectural concept of tensegrity.[6]
Starting in 2018 this concept of the fascial tissue serving as a body-wide tensional support system has been successfully expressed as an educational model with the Fascial Net Plastination Project.
Fascial tissues – particularly those with tendinous or aponeurotic properties – are also able to store and release elastic potential energy.
Photo of cross-sectional slice from a plastinated human thigh.
Schematic drawing of a transverse section of the thigh illustrating its fascial anatomy.
Clinical significance
Fascia itself becomes clinically important when it loses stiffness, becomes too stiff, or has decreased shearing ability.[7] When inflammatory fasciitis or trauma causes fibrosis and adhesions, fascial tissue fails to differentiate the adjacent structures effectively. This can happen after surgery, where the fascia has been incised and healing includes a scar that traverses the surrounding structures.
The Fascial Net Plastination Project (FNPP) is an anatomical research initiative spearheaded by fascia researcher Robert Schleip. The project aims to enhance the study of fascia through the technique of plastination. Led by an international team of fascia experts and anatomists, the FNPP resulted in the creation of a full-body fascia plastinate known as FR:EIA (Fascia Revealed: Educating Interconnected Anatomy).[8] This plastinate provides a detailed view of the human fascial network, allowing for a better understanding of its structure and function as an interconnected tissue throughout the body.
FR:EIA was unveiled at the 2021 Fascia Research Congress and is currently exhibited at the Body Worlds exhibition in Berlin. This project represents a significant contribution to the visualization of fascia and has the potential to influence future research in fields such as medicine, physical therapy, and movement science.[8][9]
Terminology
There exists some controversy about what structures are considered "fascia" and how they should be classified.[10][11]
The current version of the International Federation of Associations of Anatomists divides into:[10]
Fascia craniocervicalis
Fascia trunci
Fascia parietalis
Fascia extraserosalis
Fascia visceralis
Fasciae membrorum
Fasciae musculorum
Fascia investiens
Fascia propria musculi
Previous terminology
Two former, rather commonly used systems are:
The one specified in the 1983 edition of Nomina Anatomica (NA 1983)
Due to its viscoelastic properties, superficial fascia can stretch to accommodate the deposition of adipose that accompanies both ordinary and prenatal weight gain. After pregnancy and weight loss, the superficial fascia slowly reverts to its original level of tension.
Visceral
Visceral fascia (also called subserous fascia) suspends the organs within their cavities and wraps them in layers of connective tissue membranes. Each of the organs is covered in a double layer of fascia; these layers are separated by a thin serous membrane.
The outermost wall of the organ is known as the parietal layer
The skin of the organ is known as the visceral layer. The organs have specialized names for their visceral fasciae. In the brain, they are known as meninges; in the heart they are known as pericardia; in the lungs, they are known as pleurae; and in the abdomen, they are known as peritonea.[17]
Visceral fascia is less extensible than superficial fascia. Due to its suspensory role for the organs, it needs to maintain its tone rather consistently. If it is too lax, it contributes to organ prolapse, yet if it is hypertonic, it restricts proper organ motility.[18]
^Gatt, Adrianna; Agarwal, Sanjay; Zito, Patrick M. (2023), "Anatomy, Fascia Layers", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID30252294, retrieved 2023-05-16
^Committee on Anatomical Termi, Federative (1998). Terminologia Anatomica: International Anatomical Terminology. Thieme Stuttgart. p. 33. ISBN3-13-114361-4.It is acknowledged that the various definitions of fascia
offered by recognised authorities do not enjoy universal agreement and all have varying deficiencies. These definitions currently
fall short of an agreed, descriptive, fully embracing definition that would suit all interested medical agencies/researchers and allied
disciplines (16).
^Skandalakis, John E.; Skandalakis, P.N.; Skandalakis, L.J.; Skandalakis, J. (2002). Surgical Anatomy and Technique, 2nd Ed. Atlanta, GA: Springer. pp. 1–2. ISBN0-387-98752-5.
^Skandalakis, John E.; Skandalakis, P.N.; Skandalakis, L.J.; Skandalakis, J. (2002). Surgical Anatomy and Technique, 2nd Ed. Atlanta, GA: Springer. pp. 1–2. ISBN0-387-98752-5.
^Paoletti, Serge (2006). The Fasciae: Anatomy, Dysfunction & Treatment. Seattle, WA: Eastland Press. pp. 23–24. ISBN0-939616-53-X.
^Stecco, Carla (2015). Functional Atlas of the Human Fascial System. Edinburgh, UK: Churchill Livingstone Elsevier. p. 59. ISBN978-0-7020-4430-4.
^Schleip, Robert (2003). "Fascial plasticity – a new neurobiological explanation: Part 1". Journal of Bodywork and Movement Therapies. 7 (1): 11–9. doi:10.1016/S1360-8592(02)00067-0.