Cold Steel, Hot Air: The Rise and Reinvention of Scraping Therapy
How Ancient Scraping, Expensive Stainless Steel, and the Legend of the Double Bevel Created an Industry
I bought my first gua sha (massage) tool around 2008, I had been personal training and providing a fair amount of stretching services and at least one of my clients wanted to continue, regardless of the venue.
I had previously bought a massage table, on a whim, for I’m not sure what, I had only taken one massage class, it was on reflexology.
The main massage I had seen I believe was on a video I had purchased from the late, great Charlie Francis (https://www.charliefrancis.com/) which featured a practitioner performing Active release techniques (pin and stretch), electro acupuncture, and gua sha on a sprinter. I was mesmerized, I’m not sure how many times I watched that video.
Anyway, I then purchased a tool or two from a website in Twain, it was only of the only places you could buy such a tool, I do remember it was between five and seven dollars.
Over the next several years, I would watch that Charlie Francis video, take notes and then work on clients at my home and at a chiropractor where I worked over the next several years. It was great experience, no one telling me this was right and that was wrong, I just tried different strokes, techniques and see what worked.
I initially bought a gua sha tool because I thought it looked cool (they where made out of bone and stone), but quickly found out that doing massage was hard work, hard on your hands, arms, shoulders, back. I found out that there are muscles all on each segment of your fingers which can get sore. I then begin to use the massage tools to help spare my hands and found that it actually worked better for certain areas of the body.
Around this time ASTYM was all rage in the Physical Therapy clinics in the area, the tools were so special that you couldn’t buy them, you had to rent them. "Not lease. Not finance. Rent. Apparently the therapeutic properties of ASTYM tools became unstable if they left the approved ecosystem."
Additionally Graston then was becoming popular, usually performed by chiropractors and everyone of them could expound verbatim about the benefits of the double bevel tool, which where only available in the Graston tools.
Kind of humorous now that I think about it, at the time I was speaking with a chiropractor at a race even and he was extolling me the virtues of the double bevel tool and I remember looking at them, thinking they looked pretty similar to my five dollar Taiwanese tools and I was trying to understand what the big difference was.
Looking back, that conversation stuck with me.
Not because I suddenly became convinced the double bevel possessed magical therapeutic properties, but because it was probably my first exposure to a pattern that I would see repeatedly throughout my career.
In rehabilitation, an old idea often gets repackaged with a new explanation, a proprietary tool, a certification course, and eventually an entire industry built around it.
Scraping wasn't new.
Soft tissue treatment wasn't new.
Using tools to save your hands wasn't new.
Yet somehow a practice that had existed in various forms for centuries was transformed into one of the hottest trends in rehabilitation.
What followed was a fascinating progression from Gua Sha to ASTYM, from ASTYM to Graston, from Graston to IASTM, and from "breaking up scar tissue" to mechanotransduction, fascia remodeling, and neuroscience.
The tools barely changed.
The explanations changed every few years. (That's usually a clue worth paying attention to.)
And that's where this story begins.
If you've been in physical therapy long enough, you've probably watched instrument-assisted soft tissue mobilization (IASTM) evolve through several different explanations.
First it was:
"We're breaking up scar tissue."
Then it became:
"We're stimulating fibroblasts."
Later it was:
"We're remodeling fascia."
Today it's often:
"We're providing mechanotransduction and neurosensory input."
The tools haven't changed much.
The explanation has.
In many ways, the history of IASTM is a perfect case study in how rehabilitation trends evolve: an old treatment gets a new name, a compelling biological explanation, an expensive certification course, and eventually an entire industry built around it.
Before ASTYM: Nothing New Under the Sun
Long before Graston, HawkGrips, RockBlades, or any modern certification course, clinicians were using tools to treat soft tissues.
Traditional Chinese medicine utilized scraping techniques such as Gua Sha. Manual therapists used wooden, horn, and metal instruments. Orthopedic physician James Cyriax popularized deep transverse friction massage throughout the mid-20th century, attempting to influence healing tissues through mechanical stimulation (Cyriax, 1982).
The concept wasn't revolutionary:
Find tissue that feels abnormal.
Apply pressure.
Hope it feels and functions better afterward.
The modern industry largely replaced fingers with polished stainless steel.
The Birth of ASTYM
In the 1990s, clinicians and researchers developed ASTYM (Augmented Soft Tissue Mobilization).
Unlike many manual therapies of the era, ASTYM attempted to provide a biological explanation for treatment effects. Instead of claiming tissue was being mechanically broken apart, proponents suggested controlled mechanical stimulation could activate fibroblasts, promote collagen remodeling, and facilitate tissue regeneration.
At the time, this represented a significant shift from traditional soft tissue work. The idea fit well with emerging research on tissue adaptation and mechanobiology.
Whether these proposed cellular changes occur to a clinically meaningful degree in humans remains far less certain.
Enter Graston: When Manual Therapy Became a Business Model
The real explosion occurred with the development of the Graston Technique.
David Graston reportedly began experimenting with metal instruments after a knee injury. The concept evolved into an entire certification system complete with proprietary tools, training courses, treatment algorithms, and continuing education programs (Cheatham et al., 2019).
And honestly, it was brilliant.
Clinicians received:
Expensive stainless-steel instruments
Weekend certifications
A compelling treatment narrative
Something visually impressive for patients
Patients received:
A treatment that felt different
Visible skin changes
A convincing explanation
Everybody left happy.
At least initially.
The Scar Tissue Era
From roughly 2000 to 2015, the dominant explanation was simple:
"We're breaking up scar tissue and adhesions."
This idea spread everywhere.
Continuing education courses taught it.
Patients repeated it.
Clinicians repeated it.
The problem is that biology never really cooperated.
Consider that:
Tendons tolerate enormous tensile loads.
Surgical adhesions frequently require surgery to release.
Dense fibrosis can withstand forces vastly greater than those generated by a handheld instrument.
The notion that a clinician could physically shred years of scar tissue using a metal tool applied through intact skin became increasingly difficult to defend scientifically.
Many clinicians eventually noticed something interesting:
Patients often improved.
But there was very little evidence that scar tissue was actually being "broken apart."
The Purple Dots Era
For a while, the effectiveness of treatment seemed directly proportional to how much a patient looked like they lost a fight with a paintball gun.
Patients were often told the red spots represented toxins, inflammation leaving the body, broken adhesions, stagnant blood, or some other physiological event that sounded impressive but rarely had evidence behind it.
In reality, the marks were largely a predictable response to repeated mechanical stress applied to superficial tissues.
Yet for many years, the appearance of bruising became part of the treatment's perceived effectiveness.
The more dramatic the marks, the more powerful the treatment seemed.
The marks themselves became a form of visual biofeedback.
Patients could see something happened.
Clinicians could point to something happened.
Whether the marks actually represented the explanation being offered was another question entirely.
A patient can't see pain modulation.
They can't see changes in pressure sensitivity.
They can't see improved movement confidence.
They can see a bright red streak running down their calf.
And for a time, many clinicians mistook visible evidence of treatment for evidence of mechanism.
The Great Double-Bevel Debate
No discussion of IASTM history would be complete without mentioning the almost mythical importance once assigned to instrument design.
If you attended courses during the early 2000s, you may remember detailed lectures explaining why one edge was superior to another, why a particular curve matched the anatomy better, or why a specific bevel angle could somehow detect tissue restrictions hidden beneath the skin.
Particular attention was often given to the double-bevel edge, which was marketed as a major advancement in tissue detection and treatment effectiveness.
Clinicians were taught that the instrument could "amplify tactile feedback," allowing them to locate adhesions, fibrosis, and scar tissue with remarkable precision.
The implication was often that the tool itself possessed a level of diagnostic capability bordering on supernatural.
Unfortunately, the research never really caught up to the marketing.
While experienced clinicians can certainly appreciate differences in tissue resistance through an instrument, there is little evidence that a double-beveled stainless-steel edge can reliably identify specific pathological tissue changes or distinguish one diagnosis from another (Cheatham et al., 2019).
Looking back, the profession spent years debating whether a single-bevel or double-bevel edge was superior at finding scar tissue, only to eventually realize we weren't even sure scar tissue was the thing we were feeling in the first place.
The Stainless-Steel Mystique
Of course, the double bevel wasn't the only feature that acquired near-mythical status.
The material itself became part of the sales pitch.
Early IASTM systems emphasized the superiority of cold, polished, surgical-grade stainless steel. The instruments looked less like massage tools and more like something borrowed from an operating room. They were heavy. They were shiny. They came in foam-lined cases. They looked expensive because they were expensive.
And that's exactly what made them appealing.
A patient lying on a treatment table might reasonably think:
"That thing looks serious."
A plastic scraper from a massage supply company?
Not nearly as impressive.
Over time, manufacturers introduced plastic, polymer, resin, and composite instruments that often produced remarkably similar clinical results. Some clinicians even found them more comfortable, lighter, and easier to use throughout the day.
Yet many therapists remained convinced that stainless steel possessed special therapeutic properties.
The explanations varied:
Better vibration transmission
Enhanced tactile feedback
Superior tissue resonance
Greater tissue penetration
More effective scar tissue disruption
Unfortunately, evidence supporting these claims remains sparse.
The reality is that most of the force generated during IASTM comes from the clinician, not the metallurgy. The instrument simply acts as a force-transmission device between therapist and patient.
Whether that force passes through a $2,000 polished stainless-steel instrument or a $20 molded polymer scraper is unlikely to fundamentally alter fibroblast activity, collagen remodeling, or pain modulation.
Somewhere along the way, physical therapists became convinced that fibroblasts could tell the difference between a surgical-grade stainless-steel instrument and a plastic scraper ordered online for the price of a pizza.
The stainless steel certainly changed something.
Whether it was the patient's tissue or the clinic owner's credit card bill remains open to debate.
The Shift to Mechanotransduction
As research evolved, so did the explanation.
Modern IASTM proponents more commonly discuss:
Mechanotransduction
Connective tissue remodeling
Neuromodulation
Sensory input
Pain modulation
Load tolerance
Movement confidence
This shift reflects the broader evolution of rehabilitation science.
The older explanation became harder to support, so the profession moved toward explanations that better fit current understanding of pain, tissue adaptation, and nervous system responses (Cheatham et al., 2019).
In fact, one of the most comprehensive reviews of IASTM notes that evidence supporting connective tissue remodeling in humans remains largely theoretical and has not been clearly confirmed through human clinical trials (Nazari et al., 2019).
ASTYM Becomes IASTM
As more companies entered the market, the profession needed a broader term.
Thus, IASTM (Instrument-Assisted Soft Tissue Mobilization) became the umbrella category.
Under that umbrella now sit:
ASTYM
Graston
HawkGrips
RockBlades
Técnica Gavilán
FAKTR
Numerous generic scraping systems
The tools vary.
The marketing varies.
The treatment itself often looks remarkably similar.
What Does the Research Actually Show?
The evidence is far less dramatic than many certification courses would suggest.
A systematic review by Seffrin and colleagues found mixed evidence for IASTM. Improvements in range of motion appear somewhat more consistent than improvements in pain, strength, or function. Many studies remain small, heterogeneous, and methodologically limited (Seffrin et al., 2019).
Similarly, Cheatham and colleagues noted that much of the IASTM literature consists of case reports and lower-level evidence, with limited consensus regarding treatment parameters, indications, or mechanisms (Cheatham et al., 2019).
The most reasonable interpretation of the current evidence is that IASTM may:
Temporarily reduce pain
Improve short-term range of motion
Alter pressure sensitivity
Improve tolerance to movement
Serve as a useful adjunct to exercise
But whether a metal instrument is uniquely necessary remains unclear.
The Clinical Reality Version
The history of IASTM is not the story of a revolutionary discovery.
It's the story of an old idea being repeatedly repackaged.
First it was scraping.
Then ASTYM.
Then Graston.
Then IASTM.
Then fascia.
Then mechanotransduction.
Then neuroscience.
The treatment changed very little.
The explanation changed every few years.
Does that mean IASTM is useless?
Not at all.
Many patients feel better after it.
Many clinicians find it useful.
The more interesting question is whether the benefit comes from some magical ability to carve scar tissue apart—or whether it comes from the same reasons many manual therapies work:
Sensory input
Pain modulation
Therapeutic interaction
Expectation effects
Improved movement confidence
Temporary changes in tissue tolerance
The answer is probably much closer to the latter.
In other words, IASTM may not be a sophisticated scar-tissue-remodeling technology.
It might simply be manual therapy wearing a stainless-steel Halloween costume.
What I Use Today
After spending several thousand words making fun of the mythology surrounding scraping tools (and thousands of dollars continuing education), it's probably worth mentioning that I still use them.
Not because I think they're breaking up scar tissue.
Not because I think fibroblasts can identify surgical-grade stainless steel.
And not because I believe the double bevel possesses mystical diagnostic powers.
I use them because they provide a convenient way to apply a different pressure than my hands and to give my hands a break.
Ironically, after years of being told that cold, polished stainless steel was somehow superior, my current favorite tools are inexpensive plastic Gua Sha tools from: https://guashatools-com.myshopify.com/
Why plastic?
Because they're practical.
* They're lighter.
* They're easier to grip.
* They don't fatigue my hands as quickly.
* They don't feel like an ice cube in a patient's treatment session.
* If I drop one, I'm not worried about damaging a $300 instrument.
In other words, I prefer them for the same reasons I prefer most clinical tools: they help me do my job.
Which raises an uncomfortable question:
If the treatment works just as well with a lightweight plastic tool, how important was all that talk about surgical-grade stainless steel, proprietary alloys, vibration transmission, tissue resonance, and the legendary double bevel?
The answer is probably the same answer we often discover in rehabilitation:
The fancy explanation was far more important to the marketing than it was to the outcome.
Twenty years ago I bought a five-dollar Taiwanese scraper because I thought it looked cool.
Two decades, countless certifications, proprietary tools, double bevels, scar tissue theories, fascia lectures, and mechanotransduction explanations later, I still find myself reaching for something remarkably similar.
The biggest changes didn’t happened in the tools.
They happened in the stories we told about them.
-the Pissed-Off PT- tell me your thoughts, suggestions for other articles-
References
Cheatham SW, Baker R, Kreiswirth E. Instrument Assisted Soft-Tissue Mobilization: A Commentary on Clinical Practice Guidelines for Rehabilitation Professionals. International Journal of Sports Physical Therapy. 2019;14(4):670-682.
Cyriax J. Textbook of Orthopaedic Medicine. Vol 2. London: Baillière Tindall; 1982.
Hammer WI. Functional Soft-Tissue Examination and Treatment by Manual Methods. 3rd ed. Jones & Bartlett Learning; 2007.
Nazari G, Bobos P, MacDermid JC, Szekeres M. The Effectiveness of Instrument-Assisted Soft Tissue Mobilization in Athletes, Participants Without Musculoskeletal Disorders, and Individuals With Upper-Extremity, Lower-Extremity, and Spinal Conditions: A Systematic Review. Archives of Rehabilitation Research and Clinical Translation. 2019;1(3-4):100017.
Seffrin CB, Cattano NM, Reed MA, Gardiner-Shires AM. Instrument-Assisted Soft Tissue Mobilization: A Systematic Review and Effect-Size Analysis. Journal of Athletic Training. 2019;54(7):808-821.