The Claim
It is a common claim in manual therapy marketing and clinical conversation alike: that sufficiently firm, targeted pressure from a therapist's hands, elbow or an instrument can physically "break down" scar tissue or dense fibrous adhesions, freeing the surrounding tissue and restoring normal movement.
The idea has intuitive appeal — scar tissue often does feel dense and restrictive under palpation, and clients frequently do feel looser immediately after treatment. The question is whether the mechanism is what it is commonly described as.
The Force Problem
Mature scar tissue and dense fascia are remarkably stiff. Using a three-dimensional mathematical model built from the measured mechanical properties of human fascia, Chaudhry and colleagues calculated the force required to produce even a modest 1% compression and 1% shear deformation in tissues such as the fascia lata (the dense fascia of the outer thigh) and plantar fascia. Their conclusion was unambiguous: the forces required were "outside the normal physiologic range" achievable by manual pressure, and the authors stated explicitly that the palpable sensation of tissue "release" so often reported in clinical practice "cannot be due to deformations produced in the firm tissues of plantar fascia and fascia lata" (Chaudhry et al., 2008).
Later work by the same research group modelling how forces transmit through skin, fat and fascia in combination reached a similar conclusion: dense fascia experiences substantially less deformation than the more pliable skin and adipose layers overlying it for a given applied force (Chaudhry et al., 2014).
What Might Be Happening Instead
None of this means manual therapy applied to scarred or fibrotic tissue is doing nothing — it means the mechanism is very unlikely to be literal mechanical disruption of collagen cross-links. A few more plausible explanations have reasonable support. Modelling the behaviour of hyaluronic acid — the lubricating fluid found between fascial layers — under manual therapy motions, Roman and colleagues found that sliding, vibration and oscillation techniques increased local fluid pressure in ways that could improve gliding between tissue layers without requiring the fascia itself to be structurally altered (Roman et al., 2013). Equally important are neurophysiological contributions: sustained pressure modulates local nociception, reduces protective muscle guarding, and can produce a genuine, immediate sensation of ease that has nothing to do with the collagen architecture of the scar itself.
Collagen remodelling in scar tissue is real, but it is a biological process — governed by fibroblast activity, cross-link turnover and loading over weeks to months — not something accomplished in the twenty minutes of a treatment session through manual force alone.
The Verdict
The forces required to mechanically deform mature scar tissue or dense fascia are well beyond what manual pressure can generate, and biomechanical modelling confirms this directly. The genuine benefits clients experience after treatment to scarred or fibrotic areas are better explained by fluid dynamics between tissue layers, reduced protective guarding, and neurophysiological pain modulation — with true structural remodelling occurring gradually over time through the body's own biological processes, supported by progressive loading rather than manual force alone.
References & Further Reading
- Chaudhry H, Schleip R, Ji Z, Bukiet B, Maney M, Findley T. Three-dimensional mathematical model for deformation of human fasciae in manual therapy. J Am Osteopath Assoc. 2008;108(8):379-390.
- Chaudhry H, Bukiet B, Ji Z, Stecco A, Findley TW. Deformations experienced in the human skin, adipose tissue, and fascia in osteopathic manipulative medicine. J Am Osteopath Assoc. 2014;114(10):780-787.
- Roman M, Chaudhry H, Bukiet B, Stecco A, Findley TW. Mathematical analysis of the flow of hyaluronic acid around fascia during manual therapy motions. J Am Osteopath Assoc. 2013;113(8):600-610.