The Science Behind Fascial Manipulation
Most clinical training builds the body from bones, joints and named muscles. That model works well for a fracture or a tear. It struggles with pain that moves, stiffness with no matching lesion, or a problem that keeps coming back. This page sets out what research now shows about fascia, the tissue that model leaves out, and what it does and doesn’t yet tell us about treatment.
What Fascia Is
Fascia is easiest to understand as a system rather than a single tissue. A 2025 paper by an international group of anatomists describes the fascial system as a layered, body-wide network of connective tissue that lets tension be carried and lets neighbouring layers slide over one another.[1]
Throughout that network, two kinds of layer alternate. Collagen-rich layers are relatively stiff and carry load. Between them sit thinner, looser layers rich in hyaluronan, a molecule that binds water and lets adjacent layers glide.[1] Specialised cells within fascia, called fasciacytes, are among those thought to help maintain this gliding layer.[2]
That pairing of strength and mobility is the thread running through everything below.
Superficial fascia
The layered connective tissue beneath the skin.
Deep (musculoskeletal) fascia
Wraps and links muscles, and includes tendons, ligaments, joint capsules and the connective tissue within muscle.
Visceral fascia
Supports and separates the internal organs.
Neural fascia
Surrounds peripheral nerves, the brain and the spinal cord.
The four parts of the fascial system as grouped in the 2025 proposal.[1] Fascial Manipulation works mainly with the deep fascia in Levels 1 and 2.
What Happened to Fascia
For most of the twentieth century, fascia was the tissue anatomists cut through to reach the structures underneath, and it was largely treated as inert packing material. Part of the reason is practical: traditional specimen preparation destroys the very properties that make fascia interesting. Layers that glide independently in a living body fuse into a single stiff sheet once preserved.
Over the past two decades that view has been steadily revised, with much of the anatomical work coming from the Stecco research group at the University of Padua.[3, 4] Even the definition of fascia is still being refined, which is part of why the word is used so loosely in clinical conversation.[1, 5]
Biceps brachii is a simple example of what the older model missed: alongside its tendon into bone, it inserts into the deep fascia of the forearm through the lacertus fibrosus.
What Fascia Does
01It connects muscles into a working network
Muscles are wrapped in connective tissue from the individual fibre outwards, and that tissue is continuous with the deep fascia. Force produced by a muscle doesn’t only travel along its tendon to bone. A meaningful share is transmitted sideways, through fascia, to neighbouring muscles.[4, 6, 7] Animal and laboratory studies suggest fascia can carry up to around 30% of a muscle’s force. Studies in living people also support force transmission through fascia, but most are small, and how much force it carries in the human body isn’t yet known.[8]
A systematic review of dissection studies found strong anatomical evidence for some of the proposed muscle-to-muscle connections, such as the line running from the sole of the foot, up the back of the leg, to the lower back. It found little or no evidence for others, and noted that whether these connections matter clinically still needs to be tested.[9] A 2025 review reached a similar conclusion: the anatomical continuity is well documented, while its functional significance is still being worked out.[8]
Fascia is also not entirely passive. It contains contractile cells called myofibroblasts, which in laboratory studies can change fascial tension, although how much this matters in the living body is unclear.[8]
The low back shows these connections especially clearly. Here the thoracolumbar fascia acts as a crossroads, where muscles from the arm and shoulder (latissimus dorsi and trapezius), the hip and thigh (gluteus maximus, and biceps femoris by way of the sacrotuberous ligament) and the trunk all attach. In dissection studies, pulling on latissimus dorsi or gluteus maximus moved this fascia across the midline to the opposite side, so the shoulder on one side and the hip on the other can both put it under tension. The thoracolumbar fascia also wraps the back muscles in a tight sheath, which is thought to help them support the lower spine.[36]
These connections are also visible in how people move. In chronic low back pain, changes in muscle recruitment can be seen along the kinetic chain, from the neck to the lower leg, not only in the back itself.[30] Injury elsewhere has a similar reach: after an ankle sprain, or with chronic ankle instability, the activation of muscles at the hip and trunk changes too.[31, 32] One proposal is that fascia helps organise muscles into coordinated groups, so a problem in one part of a chain can change how the whole chain is recruited.[33]
Together, these are reasons a problem in one area could load or alter a distant but connected region, and part of the rationale for assessing beyond the painful area.
02It is a sensory organ
Deep fascia carries a dense network of free nerve endings and several types of mechanoreceptor. In several anatomical studies the deep fascia was more densely innervated than the muscle beneath it.[4, 10, 11] That gives fascia a role in proprioception: the ankle retinacula, for example, appear to act as specialised proprioceptive structures rather than simple tendon restraints.[12]
The same innervation means fascia can contribute to pain. When a pain-provoking solution was injected into the thoracolumbar fascia of healthy volunteers, it produced more intense and more widespread pain than the same injection into muscle.[13] This is one reason fascia is considered a possible contributor to back pain that has no clear structural cause.[14]
The thoracolumbar fascia is a good example. Studies consistently find it richly supplied with free nerve endings, including ones that carry pain signals, and it also contains a dense network of sympathetic nerve fibres, which may help explain why back pain can be influenced by stress.[11, 36] Older studies also described Pacini, Ruffini and Golgi–Mazzoni corpuscles here, but these have not been confirmed by more recent studies.[11, 36] Because this layer sits well away from the joints of the spine, nerve endings that respond to stretch may be activated by everyday movements, not only by end-of-range ones.[36]
Fascia’s sensory role also feeds into motor control. Retinacula, the local thickenings of deep fascia around joints, are especially well supplied with nerves, more so than the neighbouring ligaments,[12, 25] and damage to them after ankle sprain has been linked with ongoing symptoms.[26] Because fascia feeds information into movement control, changes in it may alter how muscles are recruited, both locally and further along the kinetic chain.[27, 31, 32] Muscle spindles appear to be affected too: in animal studies, the connective tissue around them thickened after injury, which may blunt what they sense, and this was reversed when the muscle was activated.[28, 29] The second diagram below (Three pathways to dysfunction) draws these ideas into a working model.
Fascia is richly innervated, so it can contribute to pain that imaging doesn’t explain.
When Fascia Stops Gliding
Densification is the term Fascial Manipulation uses for a localised loss of glide between fascial layers. The current model is that the hyaluronan-rich loose connective tissue becomes thicker and more viscous, so neighbouring layers no longer slide freely.[15]
This is different from fibrosis, a structural change in which the collagen fibres themselves are altered. Densification is therefore considered potentially reversible, while fibrosis is a longer-lasting change to the tissue.[15] Proposed contributors to densification include reduced movement, overload, and inflammation after injury or surgery.[15, 16]
In people with chronic low back pain, ultrasound has shown reduced shear strain, meaning less gliding, in the thoracolumbar fascia compared with people without back pain.[17] A 2025 review found the deep fascia was generally the same thickness or thicker in people with low back pain, with large variation between individuals and between studies.[18] Cadaver work has also compared hyaluronan content in densified areas with the surrounding fascia.[19]
Ultrasound is increasingly used to assess fascia, but methods are not yet standardised and results depend on the operator, so these measures are still mainly research tools.[20] For a plain-English summary, see how densification differs from scar tissue.
Can Treatment Change It?
Not in the way people often assume. Hands-on treatment can’t remodel collagen fibres in a few minutes: collagen is a stable structural protein, and changing its architecture takes sustained loading over months.
What manual treatment is thought to influence is the hyaluronan-rich loose connective tissue between the layers. Its viscosity appears to respond to temperature, hydration and mechanical stress.[15] Fascial Manipulation aims to restore glide in that layer, rather than to stretch or reshape collagen.
Researchers have started measuring this directly. A specialised MRI technique, T1ρ mapping, can distinguish water bound to glycosaminoglycans such as hyaluronan from free water in the tissue. Using it, a case series of people with chronic elbow pain found a measurable shift in the balance of bound and free water within the deep fascia after three sessions of Fascial Manipulation.[34] Other studies have reported local temperature rises after treatment, and animal studies point to anti-inflammatory and pain-modulating effects.[21] Work on these mechanisms is ongoing.
A 2023 review from the Padua and New York groups proposes why friction may produce a more lasting change than heat alone. Warmth on its own loosens the aggregated hyaluronan chains, so the tissue softens, but as it cools the chains can re-aggregate and the area tends to return to its densified state. Deep friction adds mechanical shear, which is thought to break the aggregated chains into fragments. These fragments are cleared and replaced by normal hyaluronan, so the change in the loose connective tissue, along with the fall in stiffness and nerve ending irritation, is more sustained.[35]
Applied research on Fascial Manipulation
Alongside the mechanism studies, Fascial Manipulation has been tested in clinical studies, including randomised controlled trials, across a range of musculoskeletal conditions, most often longstanding ones. These studies have looked at outcomes such as pain, disability and movement, and have been brought together in systematic and scoping reviews.[22, 23]
The most recent review pooled the results of 10 randomised trials and found that, on average, pain improved more with Fascial Manipulation than with active comparison treatments.[24] No serious adverse events have been reported.[23] This is a growing area of research, with larger trials continuing to build the evidence.
In practice, Fascial Manipulation is used as a structured clinical reasoning framework for assessment and treatment, alongside exercise and education.
Treatment aims to restore glide in the loose connective tissue, not to reshape collagen.
From Anatomy to the FM Model
Luigi Stecco’s model groups the motor units that move a body segment in one direction, together with the fascia, nerves and vessels that link them, into a myofascial unit. Each unit has a Centre of Coordination, where its forces are thought to converge. Units acting in the same direction link into sequences, and Centres of Fusion coordinate the diagonal and spiral movements between them.[4]
A 2023 review set out the anatomical support for treating the myofascial unit, rather than the individual muscle, as the basic element of peripheral motor control.[4] Researchers have also proposed the myofascial unit as part of a framework for assessing non-specific low back pain.[16] These are models: they organise the anatomy into a clinical framework that is still being tested.
How It Works Clinically
How the model guides a real assessment, from history to hypothesis to treatment.
See the clinical processThe Four Levels
How the model extends from deep fascia to the internal and superficial fascial systems.
Explore the levelsWhat Is Fascial Manipulation?
A plain-English overview, how it compares with other approaches, and key terms.
Read the overviewThree Generations of Fascia Research
Luigi Stecco
Developed the Fascial Manipulation method over more than 40 years of treating patients with musculoskeletal problems, building its anatomical and biomechanical model.
Prof. Carla Stecco
One of the most widely published fascia researchers, and author of the Functional Atlas of the Human Fascial System.
Asst. Prof. Antonio Stecco
Researches fascial densification and its imaging with ultrasound, through clinical studies of the method.
The Stecco research group has published more than 400 peer-reviewed articles.
Search Their Research on PubMedThe Evidence Behind This Page
- Stecco, C., Pratt, R., Nemetz, L. D., Schleip, R., Stecco, A., & Theise, N. D. (2025). Towards a comprehensive definition of the human fascial system. Journal of Anatomy.
- Fede, C., Pirri, C., Fan, C., Petrelli, L., Guidolin, D., De Caro, R., & Stecco, C. (2021). A closer look at the cellular and molecular components of the deep/muscular fasciae. International Journal of Molecular Sciences, 22(3), 1411.
- Stecco, C. (2014). Functional Atlas of the Human Fascial System. Elsevier Health Sciences.
- Stecco, A., Giordani, F., Fede, C., Pirri, C., De Caro, R., & Stecco, C. (2023). From muscle to the myofascial unit: Current evidence and future perspectives. International Journal of Molecular Sciences, 24(5), 4527.
- Schleip, R., Jäger, H., & Klingler, W. (2012). What is ‘fascia’? A review of different nomenclatures. Journal of Bodywork and Movement Therapies, 16(4), 496–502.
- Maas, H., & Sandercock, T. G. (2010). Force transmission between synergistic skeletal muscles through connective tissue linkages. Journal of Biomedicine & Biotechnology, 2010, 575672.
- Maas, H., & Finni, T. (2018). Mechanical coupling between muscle-tendon units reduces peak stresses. Exercise and Sport Sciences Reviews, 46(1), 26–33.
- Kalichman, L. (2025). Myofascial continuity: Review of anatomical and functional evidence. Journal of Bodywork and Movement Therapies, 45, 569–575.
- Wilke, J., Krause, F., Vogt, L., & Banzer, W. (2016). What is evidence-based about myofascial chains: A systematic review. Archives of Physical Medicine and Rehabilitation, 97(3), 454–461.
- Fede, C., Petrelli, L., Guidolin, D., Porzionato, A., Pirri, C., Fan, C., De Caro, R., & Stecco, C. (2021). Evidence of a new hidden neural network into deep fasciae. Scientific Reports, 11(1), 12623.
- Suarez-Rodriguez, V., Fede, C., Pirri, C., Petrelli, L., Loro-Ferrer, J. F., Rodriguez-Ruiz, D., De Caro, R., & Stecco, C. (2022). Fascial innervation: A systematic review of the literature. International Journal of Molecular Sciences, 23(10), 5674.
- Stecco, C., Macchi, V., Porzionato, A., Morra, A., Parenti, A., Stecco, A., et al. (2010). The ankle retinacula: Morphological evidence of the proprioceptive role of the fascial system. Cells Tissues Organs, 192(3), 200–210.
- Schilder, A., Hoheisel, U., Magerl, W., Benrath, J., Klein, T., & Treede, R.-D. (2014). Sensory findings after stimulation of the thoracolumbar fascia with hypertonic saline suggest its contribution to low back pain. Pain, 155(2), 222–231.
- Kondrup, F., Gaudreault, N., & Venne, G. (2022). The deep fascia and its role in chronic pain and pathological conditions: A review. Clinical Anatomy, 35(5), 649–659.
- Pavan, P. G., Stecco, A., Stern, R., & Stecco, C. (2014). Painful connections: Densification versus fibrosis of fascia. Current Pain and Headache Reports, 18(8), 441.
- Sikdar, S., Srbely, J., Shah, J., Assefa, Y., Stecco, A., DeStefano, S., Imamura, M., & Gerber, L. H. (2023). A model for personalized diagnostics for non-specific low back pain: The role of the myofascial unit. Frontiers in Pain Research, 4, 1237802.
- Langevin, H. M., Fox, J. R., Koptiuch, C., Badger, G. J., Greenan-Naumann, A. C., Bouffard, N. A., et al. (2011). Reduced thoracolumbar fascia shear strain in human chronic low back pain. BMC Musculoskeletal Disorders, 12, 203.
- Bonaldi, L., Berardo, A., Stecco, A., Stecco, C., & Fontanella, C. G. (2025). Assessment of the fascial system thickness in patients with and without low back pain: A narrative review. Diagnostics, 15, 2059.
- Hughes, E. J., McDermott, K., & Funk, M. F. (2019). Evaluation of hyaluronan content in areas of densification compared to adjacent areas of fascia. Journal of Bodywork and Movement Therapies, 23(2), 324–328.
- Pirri, C., Pirri, N., Macchi, V., Porzionato, A., De Caro, R., Özçakar, L., & Stecco, C. (2025). Ultrasonography of the fasciae and common pathologies: The game changer. Diagnostics, 15, 1180.
- Isaji, Y., Sasaki, D., Okuyama, K., Kurasawa, Y., Suzuki, K., Kon, Y., & Kitagawa, T. (2025). Therapeutic mechanisms of fascia manipulation: A scoping review. Journal of Back and Musculoskeletal Rehabilitation, 38(6), 1267–1276.
- Arumugam, K., & Harikesavan, K. (2021). Effectiveness of fascial manipulation on pain and disability in musculoskeletal conditions: A systematic review. Journal of Bodywork and Movement Therapies, 25, 230–239.
- Isaji, Y., Sasaki, D., Kon, Y., Kurasawa, Y., & Kitagawa, T. (2024). Fascial manipulation for musculoskeletal disorders: A scoping review. Journal of Bodywork and Movement Therapies, 40, 23–29.
- Trybulski, R., Olaniszyn, G., Smoter, M., Clemente, F. M., Vovkanych, A., & Kużdzał, A. (2026). The effects of fascial manipulation on pain: A systematic review with meta-analysis. Journal of Manual & Manipulative Therapy, 34(1), 4–15.
- Biz, C., Stecco, C., Crimì, A., Pirri, C., Fosser, M., Fede, C., Fan, C., Ruggieri, P., & De Caro, R. (2022). Are patellofemoral ligaments and retinacula distinct structures of the knee joint? An anatomic, histological and magnetic resonance imaging study. International Journal of Environmental Research and Public Health, 19(3), 1110.
- Stecco, A., Stecco, C., Macchi, V., Porzionato, A., Ferraro, C., Masiero, S., & De Caro, R. (2011). RMI study and clinical correlations of ankle retinacula damage and outcomes of ankle sprain. Surgical and Radiologic Anatomy, 33(10), 881–890.
- Brandl, A., Egner, C., Reer, R., Schmidt, T., & Schleip, R. (2022). Associations between deformation of the thoracolumbar fascia and activation of the erector spinae and multifidus muscle in patients with acute low back pain and healthy controls: A matched pair case-control study. Life, 12(11), 1735.
- James, G., Stecco, C., Blomster, L., Hall, L., Schmid, A. B., Shu, C. C., Little, C. B., Melrose, J., & Hodges, P. W. (2022). Muscle spindles of the multifidus muscle undergo structural change after intervertebral disc degeneration. European Spine Journal, 31(7), 1879–1888.
- James, G., Ahern, B., Goodwin, W., Goss, B., & Hodges, P. (2025). Structural changes of muscle spindles in the multifidus muscle after intervertebral disk injury are resolved by targeted activation of the muscle. European Spine Journal.
- Vulfsons, S., Chervonenko, S., Haddad, M., Weisman, M. H., Lavi, N., & Dar, G. (2018). Decreased amplitude of surface electromyographic recordings of muscle activation along the posterior myofascial kinematic chain in subjects with chronic nonspecific low back pain compared to healthy subjects. Journal of Back and Musculoskeletal Rehabilitation, 31(4), 785–793.
- Van Deun, S., Staes, F. F., Stappaerts, K. H., Janssens, L., Levin, O., & Peers, K. K. H. (2007). Relationship of chronic ankle instability to muscle activation patterns during the transition from double-leg to single-leg stance. The American Journal of Sports Medicine, 35(2), 274–281.
- Bullock-Saxton, J. E. (1994). Local sensation changes and altered hip muscle function following severe ankle sprain. Physical Therapy, 74(1), 17–31.
- Garofolini, A., & Svanera, D. (2019). Fascial organisation of motor synergies: A hypothesis. European Journal of Translational Myology, 29(3), 185–194.
- Menon, R. G., Oswald, S. F., Raghavan, P., Regatte, R. R., & Stecco, A. (2020). T1ρ-mapping for musculoskeletal pain diagnosis: Case series of variation of water bound glycosaminoglycans quantification before and after Fascial Manipulation® in subjects with elbow pain. International Journal of Environmental Research and Public Health, 17(3), 708.
- Stecco, A., Bonaldi, L., Fontanella, C. G., Stecco, C., & Pirri, C. (2023). The effect of mechanical stress on hyaluronan fragments’ inflammatory cascade: Clinical implications. Life, 13(12), 2277.
- Willard, F. H., Vleeming, A., Schuenke, M. D., Danneels, L., & Schleip, R. (2012). The thoracolumbar fascia: Anatomy, function and clinical considerations. Journal of Anatomy, 221(6), 507–536.
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