Carla Stecco, Rebecca Pratt, Laurice D. Nemetz, Robert Schleip, Antonio Stecco, Neil D. Theise
The landscape of anatomical terminology is notoriously challenging, characterized by historical ambiguities, inconsistent use across disciplines, and linguistic fragmentation. In their seminal paper, Towards a comprehensive definition of the human fascial system, Stecco and colleagues (2025) aim squarely at this confusion, providing clarity to an area of anatomy that, despite its fundamental importance, has struggled with definitional inconsistencies for decades.
Context and Historical Background
The concept of fascia has long eluded definitive categorization. Traditional anatomy frequently reduced fascia to a mere wrapping for muscles and organs, a limited perspective still reflected in some contemporary definitions. Indeed, Stecco et al. remind us of fascia’s evolution in anatomical discourse—from a simple covering structure to recognition as a complex, interconnected system with critical biomechanical and physiological functions. They build on the foundational work of earlier researchers, including the Federative International Programme on Anatomical Terminologies (FIPAT) and the Fascia Research Society, acknowledging historical attempts at standardizing definitions and recognizing the significant progress that previous nomenclature committees have made.
However, they also note the lingering challenges that stem from these partial definitions. The existing terminological fragmentation makes interdisciplinary research, clinical application, and teaching unnecessarily complex, underscoring the need for their present effort.
Redefining the Fascia
Central to their proposal is the reclassification of fascia from an ambiguous connective tissue or scattered anatomical components to a unified anatomical system. The authors argue compellingly that fascia should be considered not simply as tissue nor merely as individual organs, but rather as a distinct, integrated, body-wide anatomical system.
Their revised definition positions fascia as a layered, multiscale network characterized by two complementary types of connective layers:
- Stiff collagen-rich layers, provide mechanical support, tension distribution, and structural integrity.
- Viscous, hyaluronic acid-rich interstitial layers, facilitate fluid flow, sliding interfaces, and signaling pathways.
This dual nature highlights fascia’s critical role as both a structural scaffold and an adaptive matrix, capable of responding dynamically to mechanical stresses and physiological conditions.
Organizing Complexity
Stecco and colleagues suggest categorizing the fascial system into four principal anatomical organs, each reflecting distinct regional specializations:
- Superficial fascia: Connective tissue beneath the skin, essential for lymphatic drainage, protection of superficial structures, and skin mobility.
- Musculoskeletal (deep) fascia: Connective tissue associated with muscles, bones, and joints, vital for movement, force transmission, and proprioception.
- Visceral fascia: Connective tissue associated with internal organs, supporting visceral structures and enabling essential mobility and interactions.
- Neural fascia: Specialized connective tissue encompassing nervous structures, playing roles in protecting nerves and facilitating nerve mobility.
They further subdivide these organs into clearly delineated anatomical structures (e.g., periosteum, joint capsules, aponeuroses), emphasizing how each contributes uniquely to the system’s functionality.
Functional and Clinical Relevance
Beyond mere anatomical classification, the paper underscores the functional diversity and clinical significance of fascia. The authors describe how fascial tissues are uniquely positioned to transmit mechanical signals across the body, highlighting their integral roles in proprioception, force transmission, and mechanotransduction. Furthermore, they emphasize fascia’s involvement in healing, immune responses, and fluid dynamics, providing a theoretical underpinning for various therapeutic approaches, from physiotherapy and osteopathy to surgical interventions and regenerative medicine.
Recognizing the fascial system as an anatomical and physiological entity has profound implications. Clinically, understanding fascia’s systemic role could enhance diagnostic accuracy and therapeutic interventions in conditions involving chronic pain, restricted mobility, surgical complications, and even systemic inflammatory responses.
Anatomical Ontology and Scientific Precision
Stecco et al. advocate for a consistent anatomical ontology aligned with contemporary biomedical research. They stress the importance of defining anatomical structures based on both form and function. In practice, this allows clinicians and researchers to communicate more effectively, facilitating interdisciplinary collaboration and advancing anatomical science in step with technological and conceptual innovations.
Critical Considerations and Future Directions
The authors acknowledge that their proposal, though detailed and rigorous, is not without its challenges. Integrating dermis and visceral submucosae into the fascial system, for example, remains a topic for further debate and research. Additionally, delineating clear boundaries between related structures, such as tendons and ligaments, poses inherent difficulties due to their overlapping morphological and functional characteristics.
This paper serves as a call to action, urging further scholarly debate, empirical research, and clinical studies to refine and operationalize these new definitions fully. Its openness to future dialogue underscores an admirable humility and scientific rigor, recognizing that anatomy is a continually evolving field.
Conclusion: A Path Forward
In sum, Stecco and colleagues present a compelling, scientifically grounded, and clinically relevant redefinition of fascia as a systemic anatomical entity. They provide the foundational clarity sought in fascial anatomy by proposing a comprehensive, functionally precise framework. This paradigm shift not only promotes greater scientific rigor but also holds immense potential for advancing patient care through enhanced clinical understanding and therapeutic precision.
As clinicians, educators, and researchers adopt this refined fascial framework, we can anticipate accelerated advances in therapeutic practices, interdisciplinary communication, and scientific understanding. This work, therefore, represents a significant milestone in anatomy’s continuous evolution, poised to reshape our understanding of the body’s integral connective landscape.
Final Thoughts
Stecco et al.’s article is more than just a nomenclature revision; it symbolizes a crucial step toward harmonizing anatomical language with contemporary clinical and research needs. For anyone involved in clinical bodywork, therapeutic practice, or anatomical education, engaging with this work offers invaluable insights, fostering clarity and precision in their practice and scholarship.
This paper is highly recommended reading for all those interested in exploring the profound implications of fascia’s recognition as a distinct and coherent anatomical system.
Link to paper:
https://mms.fasciaresearchsociety.org/ct.php?lid=329114829&mm=244106222325
Abstract:
The absence of a clear consensus on the definition and significance of fascia and the indiscriminate use of the term throughout the clinical and scientific literature has led to skepticism regarding its importance in the human body. To address this challenge, we propose that: (1) fasciae, and the fascial interstitia within them, constitute an anatomical system, defined as a layered body-wide multiscale network of connective tissue that allows tensional loading and shearing mobility along its interfaces; (2) the fascial system comprises four anatomical organs: the superficial fascia, musculoskeletal (deep) fascia, visceral fascia, and neural fascia; (3) these organs are further composed of anatomical structures, some of which are eponymous; (4) all these fascial organs and their structural components contain variable combinations and arrangements of the four classically defined tissues: epithelial, connective, muscle, and neural; (5) the overarching functions of the fascial system arise from the contrasting biomechanical properties of the two basic types of layers distributed throughout the system: one predominantly collagenous and relatively stiff, the other rich in hyaluronic acid and viscous, allowing for the free flow of fluid; (6) the topographical organization of these layers in different locations is related to local variations in function (e.g. unidirectional arrangements favor tensional loading, interwoven structures favor shear mobility) thereby accounting for both the system’s universal functional aspects and the site-specific variations between them. A universal language related to fascia will break down linguistic barriers and facilitate cross-disciplinary cooperation, enabling scientists and practitioners from diverse backgrounds to contribute their expertise seamlessly.