04/04/2026
𝐓𝐡𝐞 "𝐀𝐝𝐡𝐞𝐬𝐢𝐨𝐧" 𝐌𝐲𝐭𝐡 — 𝐖𝐡𝐚𝐭 𝐭𝐡𝐞 𝐄𝐯𝐢𝐝𝐞𝐧𝐜𝐞 𝐀𝐜𝐭𝐮𝐚𝐥𝐥𝐲 𝐒𝐡𝐨𝐰𝐬:
"That knot in your back? That's an adhesion. I'm breaking it up right now." It sounds medical — and the treatment might even feel good, but the explanation doesn't hold up.
The claim is that muscle or fascial tissue has physically "stuck together" — formed an adhesion — and that manual pressure can break it apart. Here's what the research actually shows.
True adhesions exist — but they are not what most people experience as a “knot” or muscle tension. Pathological adhesions are dense fibrotic bands that typically form after surgery or significant inflammation — an estimated 93% of abdominal surgeries produce them (Ryan & Keeney-Smith, 2020). They cause bowel obstructions, infertility, and chronic pain (Bove et al., 2017) — and they cannot be “broken apart”. In rat models, visceral mobilization can prevent or reduce post-surgical cohesive adhesions when applied in the immediate postoperative period (Bove & Chapelle, 2012; Bove et al., 2017), but that is a far cry from a massage therapist claiming to dissolve fibrotic scar tissue through a patient's skin and muscle.
Fascia can change — just not in the way it's usually described. Ultrasound and shear-wave elastography studies have shown that in chronic pain conditions, fascial layers can become stiffer and show reduced sliding between layers (Bird et al., 2017; Turo et al., 2013) — sometimes referred to as densification, a functional rather than scar‑like change. A 2024 case study using ultrasound shear‑strain imaging reported significantly reduced shear strain between the pectoralis major and minor on the painful side compared with the unaffected side in a patient with chronic shoulder pain (Zhao et al., 2024). Ultrasound and elastography can also visualize these alterations and observe their modification following manual therapy (Luomala et al., 2014).
While 'knots' are not true adhesions, they are nonetheless significant. Research on these 'knots' (frequently termed trigger points) reveals that they do not contain distinct fibrotic adhesions yet exhibit measurable local changes.
While fascial stiffness can influence movement and perception, localized pain phenomena often described as “knots” involve a distinct set of mechanisms. Shah et al. (2008a, 2008b), in a widely cited but debated two-part series published in Archives of Physical Medicine and Rehabilitation, reported that active myofascial trigger points exhibit a distinct biochemical profile: elevated levels of substance P, CGRP, bradykinin, serotonin, norepinephrine, TNF-α, and several interleukins, along with significantly lower pH. Notably, these elevations were observed not only at trigger-point sites but also in remote, uninvolved muscle tissue.
Complementary imaging research using shear-wave elastography has demonstrated that symptomatic muscle tissue at trigger points is substantially stiffer than unaffected tissue (Turo et al., 2013).
(It is worth noting that the microdialysis findings, while highly influential, have been questioned in later commentaries due to concerns about sampling precision and reproducibility [Shah et al., 2023].)
So, while calling it an "adhesion" is inaccurate, the underlying physiology is both real and measurable.
What's actually driving the pain? Most likely a combination of interacting factors: peripheral sensitization (local nociceptor and tissue changes), central sensitization (heightened responsiveness within the nervous system), altered motor control, fascial stiffness, and psychological and contextual factors. Graven-Nielsen and Arendt-Nielsen (2002) established that central sensitization plays a critical role in the persistence, amplification, and spread of musculoskeletal pain — and that interventions should take this into account. This isn't a single-mechanism problem. It's a system-level interaction.
Can hands-on treatment help? Often, yes — but not because it's "breaking up adhesions."
Evidence suggests manual therapy produces neurophysiological, neurovascular, and neuroimmune effects, while evidence for purely biomechanical tissue change remains weak. A comprehensive 2025 living review of 62 systematic, narrative, and scoping reviews on manual therapy mechanisms (Keter et al., 2025) reported moderate‑quality evidence supporting neurovascular, neurological, and neuropeptide/neurotransmitter changes following manual therapy, and low‑quality evidence for neuroimmune, neuromuscular, and neuroendocrine changes. In contrast, evidence for purely biomechanical mechanisms was rated critically low. An earlier systematic review by Schmid et al. (2008) pooled data suggesting that joint mobilization improved outcomes by roughly 20 % compared to controls, accompanied by hypoalgesia, sympathetic activation, and motor function improvements — a pattern consistent with descending inhibitory pathways mediating the effect.
Similarly, a systematic review by Voogt et al. (2015) found moderate‑quality evidence that manual therapy increases local pressure pain thresholds in musculoskeletal pain conditions immediately after treatment. Several included trials also demonstrated widespread analgesic effects, implicating central pain modulation rather than purely peripheral biomechanical change.
These findings align with the Bialosky et al. (2009) model, which proposes that mechanical force from manual therapy initiates a cascade of neurophysiological responses across peripheral, spinal, and supraspinal levels — including activation of descending inhibitory pathways, autonomic modulation, and altered sensorimotor processing — that collectively contribute to clinical outcomes.
Emerging experimental and translational research further supports this model. Langevin et al. (2001) demonstrated that mechanical stretching of subdermal fibroblasts alters interstitial osmotic pressure and increases transcapillary blood flow, reducing expression of pro‑inflammatory cytokines. Likewise, McPartland et al. (2020) observed that shear and stretch loads during manual therapy more than doubled circulating anandamide (AEA) levels, with participants reporting corresponding analgesic and anxiolytic effects.
Collectively, this evidence indicates that manual therapy’s benefits arise from multisystem neurophysiological and biochemical mechanisms — not from directly “breaking apart” tissue. These mechanisms are real, measurable, and increasingly well‑documented; the myth is the story we tell about them.
References:
Bialosky, J. E., Bishop, M. D., Price, D. D., Robinson, M. E., & George, S. Z. (2009). The mechanisms of manual therapy in the treatment of musculoskeletal pain: A comprehensive model. Manual Therapy, 14(5), 531–538. https://doi.org/10.1016/j.math.2008.09.001
Bird, M. D., Le, D., Shah, J., Ge**er, N., Tandon, H., DeStefano, S., & Sikdar, S. (2017). Characterization of local muscle fiber anisotropy using shear wave elastography in patients with chronic myofascial pain. IEEE International Ultrasonics Symposium (IUS). https://doi.org/10.1109/ULTSYM.2017.8091631
Bove, G. M., & Chapelle, S. L. (2012). Visceral mobilization can lyse and prevent peritoneal adhesions in a rat model. Journal of Bodywork and Movement Therapies, 16(1), 76–82. https://doi.org/10.1016/j.jbmt.2011.02.004
Bove, G. M., Chapelle, S. L., Hanlon, K. E., Diamond, M. P., & Mokler, D. J. (2017). Attenuation of postoperative adhesions using a modeled manual therapy. PLoS ONE, 12(6), e0178407. https://doi.org/10.1371/journal.pone.0178407
Chaitow, L. (2015). Manual therapies and hypoalgesia: What are the mechanisms? Journal of Bodywork and Movement Therapies, 19(3), 388–392. https://doi.org/10.1016/j.jbmt.2015.05.001
Graven-Nielsen, T., & Arendt-Nielsen, L. (2002). Peripheral and central sensitization in musculoskeletal pain disorders: An experimental approach. Current Rheumatology Reports, 4(4), 313–321. https://doi.org/10.1007/S11926-002-0040-Y
Keter, D. L., Bialosky, J. E., Brochetti, K., Courtney, C. A., Funabashi, M., Karas, S., Learman, K., & Cook, C. (2025). The mechanisms of manual therapy: A living review of systematic, narrative, and scoping reviews. PLoS ONE, 20(3), e0319586. https://doi.org/10.1371/journal.pone.0319586
Luomala, T., Pihlman, M., Heiskanen, J., & Stecco, C. (2014). Case study: Could ultrasound and elastography visualize densified areas inside the deep fascia? Journal of Bodywork and Movement Therapies, 18(3), 462–468. https://doi.org/10.1016/j.jbmt.2013.11.020
Ryan, C., & Keeney-Smith, N. (2020). Scar tissue management. In Fascia, Function, and Medical Applications (pp. 235–248). CRC Press. https://doi.org/10.1201/9780429203350-18
Schmid, A., Brunner, F., Wright, A., & Bachmann, L. M. (2008). Paradigm shift in manual therapy? Evidence for a central nervous system component in the response to passive cervical joint mobilisation. Manual Therapy, 13(5), 387–396. https://doi.org/10.1016/j.math.2007.12.007
Shah, J. P. (2008a). Uncovering the biochemical milieu of myofascial trigger points using in vivo microdialysis. Journal of Musculoskeletal Pain, 16(1–2), 17–20. https://doi.org/10.1080/10582450801960099
Shah, J. P., Danoff, J. V., Desai, M. J., Parikh, S., Nakamura, L. Y., Phillips, T. M., & Ge**er, L. H. (2008b). Biochemicals associated with pain and inflammation are elevated in sites near to and remote from active myofascial trigger points. Archives of Physical Medicine and Rehabilitation, 89(1), 16–23. https://doi.org/10.1016/j.apmr.2007.10.018
Shah, J. P., Danoff, J. V., Nakamura, L. Y., & Ge**er, L. H. (2023). Response to: Letter to the Editor on "Biochemicals associated with pain and inflammation are elevated in sites near to and remote from active myofascial trigger points." Archives of Physical Medicine and Rehabilitation, 105(1), 207–208. https://doi.org/10.1016/j.apmr.2023.09.019
Turo, D., Otto, P., Gebreab, T., Armstrong, K., Ge**er, L. H., & Sikdar, S. (2013). Shear wave elastography for characterizing muscle tissue in myofascial pain syndrome. Journal of the Acoustical Society of America, 133(5), 3507. https://doi.org/10.1121/1.4805719
Voogt, L., de Vries, J., Meeus, M., Struyf, F., Meuffels, D., & Nijs, J. (2015). Analgesic effects of manual therapy in patients with musculoskeletal pain: A systematic review. Manual Therapy, 20(2), 250–256. https://doi.org/10.1016/j.math.2014.09.001
Zhao, L., Huang, J., Bell, M., & Raghavan, P. (2024). Measuring myofascial shear strain in chronic shoulder pain with ultrasound shear strain imaging: A case report. BMC Musculoskeletal Disorders, 25, 459. https://doi.org/10.1186/s12891-024-07514-x
