What Does Scraping Do, Exactly?

If you’ve spent any time in a physical therapy clinic, a chiropractor’s office, or even scrolling recovery content online, you’ve probably seen it: a clinician running a metal tool along someone’s skin, leaving behind pink or red streaks. It looks a little intense. People call it “scraping,” “Graston,” or, in technical terms, tool-assisted soft tissue mobilization (TASTM), also written as instrument-assisted soft tissue mobilization (IASTM).

What is it actually doing under the skin? Is it right for you? Let’s break it down.

Where scraping came from

The most well-known modern version of this technique, the Graston Technique®, has a surprisingly relatable origin story. It wasn’t invented in a lab. It came from one frustrated athlete trying to fix his own knee.

David Graston was an amateur water skier, a machinist by trade. After a serious knee injury, a slow recovery from surgery and conventional therapy, he decided to put his machining background to use. He shaped a set of stainless-steel instruments in his own shop, began using them on his own knee.^1-3 It worked well enough that he brought the idea to researchers at Ball Memorial Hospital and Ball State University in Muncie, Indiana, where the technique was studied, refined. In 1994, the first clinic built around the method opened right here in Indianapolis.⁴

From there, the idea spread. The original Graston patent has since expired. A whole field of similar tools, branded techniques emerged: HawkGrips, ASTYM (Augmented Soft Tissue Mobilization), FAKTR (Functional and Kinetic Treatment and Rehab), Técnica Gavilán, SMART Tools, more.⁵ Each has its own tool shapes, training, certification process. All fall under the same umbrella: using a rigid instrument to apply pressure, friction to soft tissue.

None of this is actually new. Ancient Greek and Roman athletes used a curved metal tool called a strigil to scrape the skin after exercise. Practitioners of Traditional Chinese Medicine have used gua sha, literally “to scrape away disease,” for centuries as part of a broader energetic, circulatory healing system.^5-6 Modern IASTM is, in many ways, a Western, biomechanically-focused descendant of a very old idea.

What “soft tissue” actually means

Before we get into what the tools do, it helps to define what they’re working on. Soft tissue refers to the muscles, tendons, connective tissue, most notably fascia, that wrap around and connect nearly every structure in your body. Think of fascia as a continuous, body-wide webbing that holds your muscles, organs, joints in their relative positions while still allowing them to glide against each other. When soft tissue is healthy, it is pliable, slides smoothly. When it is restricted, scarred down, irritated, that gliding gets sticky. You feel it as tightness, reduced range of motion, pain.

Scraping is one way to affect soft tissue, not the only way

There are several ways a clinician can influence how soft tissue moves, relaxes. Scraping is just one tool in a larger category:

• Manual massage: hands-on pressure, kneading to improve circulation, reduce tension
• Cupping: suction-based therapy that lifts, decompresses tissue layers
• Scraping / TASTM: instrument-based friction, pressure along the tissue
• Nervous system down-regulation: breathwork, positional rest, other techniques that calm the nervous system, allowing tissue to relax even without direct hands-on work

All of these approaches aim at a similar outcome: better tissue mobility, less guarding. Each gets there through a different mechanism.

How scraping tools work

TASTM tools are typically made of stainless steel, though some practitioners use ceramic, even traditional gua sha stone or jade tools. They come in a range of shapes: some with rounded edges, some with concave curves designed to hug a joint like the knee or elbow, some with beveled edges meant to catch, work along a specific muscle border. The shape isn’t arbitrary. Different contours are designed to match different body contours, treatment goals.

Here is an example of what one of these tools typically looks like:

The clinician applies a lubricant to reduce friction, then draws the tool across the skin in controlled strokes over the target area, using feedback from how the tissue “feels” under the tool to guide pressure, direction.

The positives and negatives

Potential benefits, per the literature:

• May help break up scar tissue, adhesions
• Can improve superficial fascial mobility
• Associated with short-term improvements in pain intensity^7,9,11
• Associated with gains in range of motion (ROM)^7,9
• Associated with improvements in patient-reported function^7,9
• May stimulate local blood flow, possibly lymphatic movement

Limitations to know about:

• Redness or a rash-like skin reaction called petechiae is common, expected. This is small, temporary capillary breakage from the friction, not bruising in the traditional sense.
• It works at a fairly surface level. It doesn’t directly address deep tissue.
• The research is mixed. Some systematic reviews, meta-analyses report meaningful short-term improvements in pain, range of motion. Others conclude the evidence is still low-quality, inconsistent, especially for people without a specific injury.^7-11 It can help. It is not a guaranteed fix. It works best as part of a broader treatment plan, not a standalone solution.

Summary and our recommendation

Tool-assisted soft tissue mobilization is one tool in a physical therapist’s toolbox, not the whole toolbox. Just like a job does not always call for a hammer, not every issue calls for scraping. Not every person will respond to it the same way. These are techniques we choose deliberately, based on your specific tissue, injury and goals. We rely on what the evidence and your body are telling us.

At The Perfect Squat, we are well-versed in all the manual, instrument-assisted tools available to physical therapists, scraping included. We use shared decision-making with every client to figure out which combination of tools will actually move the needle for your specific situation. If scraping makes sense for you, we’ll tell you why. If it doesn’t, we’ll tell you that too.

By: Dr. Sara Zehr, PT, DPT, MPH, Cert-DN
Board Certified Orthopedic Specialist

References

1. Why Pro Athletes Are Flocking To An Instrument-Assisted Healing Method Known as The Graston Technique. STACK. Available at: stack.com/a/graston-technique. Accessed September 11, 2026.
2. Graston® Technique: Modern Therapy with a Chinese Antecedent. Sci/Why. Available at: sci-why.blogspot.com. Accessed September 11, 2026.
3. What is the Graston Technique? Cary Orthopaedics. Available at: caryortho.com/what-is-the-graston-technique. Accessed September 11, 2026.
4. Entrepreneur finds financial success with deep-tissue therapy. Indianapolis Business Journal. Available at: ibj.com/articles/71613. Accessed September 11, 2026.
5. Graston / IASTM For Treating Tennis Elbow – Force Or Finesse? Tennis Elbow Classroom. Available at: tenniselbowclassroom.com/treatments/graston-iastm. Accessed September 11, 2026.
6. Gua Sha. Center for Integrative Medicine, Henry Ford Health. Available at: henryford.com/…/gua-sha. Accessed September 11, 2026.
7. Cheatham SW, Lee M, Cain M, Baker RT. Instrument-Assisted Soft Tissue Mobilization: A Systematic Review and Effect-Size Analysis. J Am Osteopath Assoc. 2016. Available at: pubmed.ncbi.nlm.nih.gov/31322903. Accessed September 11, 2026.
8. The Effectiveness of Instrument-Assisted Soft Tissue Mobilization in Athletes, Participants Without Extremity or Spinal Conditions, and Individuals with Upper Extremity, Lower Extremity, and Spinal Conditions: A Systematic Review. Arch Phys Med Rehabil. Available at: sciencedirect.com/…/S000399931930108X. Accessed September 11, 2026.
9. The effectiveness of instrument-assisted soft tissue mobilization on pain and function in patients with musculoskeletal disorders: a systematic review and meta-analysis. BMC Musculoskelet Disord. 2025. Available at: link.springer.com/…/s12891-025-08492-4. Accessed September 11, 2026.
10. The efficacy of instrument assisted soft tissue mobilization: a systematic review. Available at: pubmed.ncbi.nlm.nih.gov/27713575. Accessed September 11, 2026.
11. The Efficacy of Instrument-Assisted Soft Tissue Mobilization for Musculoskeletal Pain: A Systematic Review. J Contemp Chiropr. Available at: journal.parker.edu/article/78057. Accessed September 11, 2026.