Fascia: structure and function
What “fascia” refers to
Fascia research distinguishes “a fascia” — a membrane visible to the naked eye — from “the fascial system”, which concerns the continuity and function of connective tissue throughout the body. We follow this usage and state, for each finding, which tissue was captured and with which measurement.
| Term | How we use it |
|---|---|
| A fascia | An identifiable sheet of connective tissue that wraps, separates or connects muscles and organs. |
| Fascial system | A functional concept: the continuum of loose and dense connective tissue, studied for force transmission, movement between tissues and sensation. |
| Myofascia | Connective tissue associated with muscle fibres, muscles and muscle groups; part of the fascial system. |
| Interstitium | The extracellular environment surrounding cells and tissues — fluid and matrix — studied in relation to fascia. |
Source: Schleip, Hedley & Yucesoy, 2019: consensus on fascia nomenclature
Fibres, hyaluronan and interstitial fluid
Histological studies of deep fascia describe hyaluronan in the loose connective tissue between fibrous layers and at the boundary with muscle. These layers matter for sliding between tissues and for viscoelasticity. Stecco et al., 2011
Benias and colleagues described, in human tissues such as the bile duct, an interstitium of fluid-filled spaces supported by collagen bundles. This gives us reason to consider both fibres and fluid when framing hypotheses about Kanshoho. Benias et al., 2018
From “gel to sol” to a testable hypothesis
Research direction
Earlier descriptions of Kanshoho spoke of tissue changing “from gel to sol”. We treat this as a metaphor for a change in viscoelasticity and ease of sliding. The living response can be examined from several sides by assessing collagen fibres, the hyaluronan-containing matrix, fluid and muscle activity separately.
The decrease in muscle hardness and in shear wave speed after Kanshoho is a local mechanical finding. Dynamic ultrasound, tissue displacement and muscle activity recordings could show whether it reflects viscoelasticity, interlayer sliding, or the state of matrix and fibres.
What has been observed
In the abdominal-wall study (submitted manuscript), the 4.9 N intervention reduced shear wave speed more than the movement-matched 0.49 N control. In clinical studies and case reports, improvement in pain, function and fatigue was observed after the intervention. These findings come from different participants and different measures.
Layer-specific SWE ／ Chronic whiplash-associated disorder ／ Long COVID / ME/CFS
Sensory input and motor responses
Research direction
Our question is whether sensory input during focal loading and active movement contributes to changes in muscle activation and pain. A study could pair surface electromyography, quantitative sensory testing and standardised reflex measures with tissue measurements and symptom ratings on the same time axis.
Comparing active movement alone, focal loading alone and their combination against a common time-matched reference condition would help estimate their individual and combined contributions. Contact conditions, posture, duration and assessment procedures would be specified in advance.
These are hypotheses and proposed tests for Kanshoho. Receptor-specific pathways and the direction of autonomic responses are questions for measurement within that study design.
Autonomic responses
Research direction
Heart rate variability can help examine physiological responses alongside subjective ratings. HF power and LF/HF are interpreted together with breathing, mean heart rate, posture and recording duration (Billman, 2013 ).
Because the procedure includes active movement, a useful study would record movement, respiration, heart rate, HRV and subjective ratings on the same time axis. This would help distinguish the responses associated with each component of the procedure.
Blood, hormones and metabolites
Research direction
Changes in blood constituents are material for studying how a local intervention relates to a whole-body response. Blood counts, lipids and enzymes in the 2012 study and the recent metabolome and serum-protein work come from different participants and methods, and are reported separately.
| Direction | Related observation | Proposed test |
|---|---|---|
| Immune and inflammatory responses | White-cell count and differential in the 2012 study; retinol-related finding in the metabolome study | Separate concentration from function: measure blood volume, cell function and inflammatory markers together |
| Energy metabolism and fatigue | Free fatty acids, acylcarnitines, TCA-cycle-related metabolites | Add substrate use, activity and the course of fatigue to blood concentrations |
| Endocrine function and pain | Steroid-related metabolites | Distinguish secretion, metabolism and excretion; standardise sampling, symptoms and medication |
| Timing of local and systemic change | Studies that measured hardness or SWE together with blood indices | Test in the same participants whether the local change comes first and whether it relates to symptoms |
Blood and biochemistry in the 2012 study ／ The 21 metabolites
Candidate mechanisms and how to test them
Research direction
| Hypothesis | Where it stands | Example of a test |
|---|---|---|
| The mechanical state of local muscle and connective tissue changes | SWE response observed; the tissue component involved is the open question | Standardised SWE, dynamic ultrasound, assessment of tissue sliding, replication by independent assessors |
| Changes in sensory input and motor control contribute to pain relief | Suggested by the clinical course | Sensory testing, muscle activity, and the timing of pain against mechanical change, in a prespecified design |
| Changes in microcirculation or fluid movement contribute | Proposed in our conference abstract (Abstract C) | Direct measurement of blood flow, oxygenation and haemodynamics against a control |
| The local response is linked to biochemical and metabolic change in blood | Exploratory analyses so far | Standardised sampling; account for detection range, multiple comparisons and time course |
This table sets out study designs suggested by the results so far.
Four open questions
Research direction
- How does a change in shear wave speed correspond to changes in interlayer sliding and viscoelasticity?
- What is the temporal relation between myokine-related proteins in blood, the local tissue response and the course of symptoms?
- How can findings from the abdominal wall of healthy men be examined in the neck, and in Long COVID and ME/CFS?
- What course appears when the acute blood measurements are extended in time and paired with local assessment?
Linking mechanism to clinical effect
Measuring the local mechanical change and symptoms in the same participants establishes their order in time and whether the association repeats. Control conditions that separate the contributions of force, contact and movement will narrow the mechanism. Participants, outcomes and analysis are worked out with partners at the planning stage.
Sources
- Study A (submitted manuscript): shear wave elastography of the lateral abdominal wall in 20 healthy men, randomised crossover pilot study. Trial registration UMIN000056162. This site reports only what is public in the registry and in our symposium abstract for the 28th World Congress of the International College of Psychosomatic Medicine (ICPM 2026, Fukuoka). Full details will be added when the paper is published.
- Sakato T, Nakajima A. Rapid changes in blood metabolome induced by the low-pressure muscle relaxation technique “Kanshoho”: a randomized single-blind crossover trial. 34th Annual Meeting of the Japanese Society of Pathophysiology, 2025 (presentation slides, PDF, in Japanese)
- Manuscript B (presented at conferences; unpublished manuscript): Sakato T, Shin Y, Itai Y, Amitani H. Immediate and mid-term effects of Kanshoho in patients with chronic whiplash-associated disorders: a prospective single-arm pilot study. Presented at the 55th Annual Meeting of the Japanese Society for the Study of Chronic Pain and the 35th Annual Meeting of the Japanese Society of Pathophysiology (both 2026).
- Abstract C: Clinical improvement after low-load cervical myofascial intervention in patients with Long COVID: a case series. Poster, ICPM 2026 (Fukuoka). Two patients, including the previously published case. Presented by Haruka Amitani, 24 September 2026, poster P1-43. Official programme
- Abstract D: Softening of the deep myofascial interface after a low-force 4.9 N manual intervention: implications for Long COVID/ME/CFS. Symposium, ICPM 2026 (Fukuoka). Relates the study in 20 healthy men to the published case report. Presented by Haruka Amitani, 25 September 2026, symposium DSY11-2. Official programme
- Sakato T, Amitani H. The muscle relaxation effects of gentle, focal load (4.9–7.4 N) with a narrow contact area: a narrative review of Kanshoho and conventional manual therapies. Cureus. 2025;17(8):e89646. doi:10.7759/cureus.89646
- Sakaguchi H, Sakato T, Yamamoto K, et al. The effect of Kanshoho on low back pain (lumbago) [in Japanese]. Japanese Journal of Integrative Medicine. 2012;5(1):62–67 (PDF)
Sections marked “Research direction” describe hypotheses and proposed studies for discussion with collaborators. Observations are presented with their participants, methods and sources.
Last updated: 21 September 2026