IASTM (Graston Technique): What It Actually Does and What the Evidence Shows

If you've had a stubborn bit of tendon or muscle worked on with a metal or plastic tool that looks a bit like a butter knife, you've had instrument-assisted soft tissue mobilisation, usually shortened to IASTM. Graston Technique is the best-known branded version of it, the way Hills Hoist is the best-known branded version of a rotary clothesline. Same idea, different manufacturer.

It's had a strange run in the wellness world. Some of the marketing around it borders on magic, scar tissue "broken up" and "released" in a single pass, old injuries fixed with the right stroke pattern. None of that is how tissue actually responds to being scraped with a tool. So it's worth asking plainly: what is IASTM actually meant to do, and what does the current evidence say happens when someone uses it on you.

What is IASTM or the Graston Technique?

IASTM uses a rigid tool, metal, plastic or occasionally stone, dragged or scraped across skin over a muscle, tendon or fascia with enough pressure to load the tissue underneath. Practitioners use it on tendons (Achilles, patellar, elbow), on chronically tight or restricted muscle (calves, quads, the muscles either side of the spine) and on scar tissue after surgery or a significant soft tissue injury.

The tool doesn't do anything a pair of hands technically couldn't. What it does well is transmit a consistent, sustained pressure without the practitioner's hands fatiguing, and it gives a specific tactile feedback, a catch or a gritty feel, that can help find where tissue is more restricted than the area around it. That's the honest mechanical case for using a tool instead of hands. It is not a different category of treatment to firm, sustained manual pressure.

Does IASTM actually work?

Two recent systematic reviews give a genuinely useful, and genuinely mixed, picture.

A 2025 review in BMC Musculoskeletal Disorders pooled 11 randomised controlled trials (427 participants) across conditions including cervicogenic headache, chronic neck pain, frozen shoulder, plantar fasciitis, Achilles and elbow tendinopathy, and chronic ankle instability. It found moderate-certainty evidence that IASTM reduces patient-reported pain, and lower-certainty evidence that it improves function, when it was used alongside other treatment rather than by itself (Tang et al., 2025).

A second review in the European Journal of Medical Research, pooling 20 trials and 1,420 participants across plantar fasciitis, frozen shoulder, knee osteoarthritis and neck pain, found a similar pattern: a moderate, statistically real reduction in pain and improvement in range of motion, with the effect more consistent when IASTM was combined with standard rehab rather than used as a stand-alone treatment (Liu et al., 2026).

Read plainly, that's a real, moderate, short-term effect on pain and movement, most reliable as one part of a broader plan rather than the plan itself. That's a decent evidence position. It is also a considerably more modest one than "breaks up scar tissue and speeds healing", which is closer to what a lot of local marketing on this technique claims.

Which IASTM claims are not supported by research?

A few specific claims are worth naming, because they show up often and don't hold up well.

"It breaks down scar tissue." There's no good evidence that scraping skin with a tool mechanically breaks down mature scar tissue or fascial adhesions in any way visible on imaging. The pain and mobility changes seen in trials are more likely explained by a local nervous system response to pressure and by the same general effects seen with other manual therapies, not by tissue being physically remodelled in one session.

"It speeds healing." Bruising and mild local inflammation is a normal, expected reaction to firm IASTM pressure. That's tissue reacting to load, not tissue healing faster. There's no trial evidence that IASTM shortens the biological timeline for a tendon or muscle to actually repair.

Celebrity or anecdotal endorsement. You'll see mentions of athletes who've used the technique as evidence that it works. An athlete's subjective experience of recovery, with everything else they're also doing at the same time, tells you nothing reliable about the treatment on its own. That's not a criticism specific to IASTM. It's true of every hands-on therapy and it's exactly why trials exist.

What conditions might IASTM help with?

Based on the current trial evidence, IASTM has a reasonable case as one part of managing:

• Tendon pain that's been hanging around, such as Achilles or elbow tendinopathy, alongside a loading program
• Restricted, tight muscle that isn't responding well to stretching alone
• Post-surgical or post-injury scar tissue that's genuinely limiting movement, as an adjunct to graded exercise
• Chronic neck or shoulder tightness alongside manual therapy and exercise, similar in principle to how dry needling fits into the same kind of plan

It's a supporting tool, not a headline act. Nobody should expect a single pass with an IASTM instrument to resolve a problem that loading, posture and time haven't.

What happens during an IASTM session?

In practice, it's a five-to-ten-minute part of a longer session, not the whole appointment. The area is usually warmed up first, the tool is used with enough pressure to feel firm rather than sharp, and mild redness or light bruising afterward is normal and expected, not a sign that deep tissue damage has occurred. It's typically paired with the exercise or loading work that the evidence above says actually carries most of the long-term benefit.

It isn't suitable over broken skin, active skin infections, in areas with a suspected fracture, over a deep vein thrombosis, or for people on blood thinners without a clear conversation first about bruising risk. If any of that applies to you, say so before treatment starts.

Is IASTM the same as dry needling?

IASTM and dry needling get lumped together a lot, since both can leave a mark and both get filed under "the sciency-sounding stuff". They're not the same tool for the same job. Dry needling works on trigger points and muscle tone using a fine filiform needle, and the evidence base for that sits mostly around neck and shoulder tension, covered in more detail here. IASTM works on the surface and the tissue just under it, using a rigid tool and mechanical pressure, and the evidence base above sits mostly around tendon pain and restricted movement. Worth knowing which one is actually indicated for what you've got, rather than picking whichever one sounds more advanced.

Where does IASTM fit into a rehabilitation plan?

On the gym floor at PT Central, IASTM comes up most with tendon-loading issues in lifters and runners, someone whose Achilles or elbow has been niggling for a few weeks despite doing the obvious things. It sits alongside manual therapy, dry needling and, most importantly, a structured loading program, rather than replacing any of them. If a clinic offers IASTM as the whole treatment plan with no exercise component, that's worth a question.

Is IASTM worth trying?

IASTM has a real, moderate, mostly short-term effect on pain and movement when it's used as part of a broader plan. It doesn't dissolve scar tissue, it doesn't speed up biological healing, and a good outcome from it says more about the loading program around it than about the tool itself. That's a decent reason to use it. It isn't a reason to expect it to do more than that.

If you've been told IASTM alone will fix a tendon problem that's been dragging on for months, that's a reasonable thing to be sceptical of. If it's offered as one part of a plan that also includes graded loading, the evidence backs that combination up.