What Is Shockwave Therapy?

The Meaning of Shockwave Therapy

Extracorporeal shockwave therapy (ESWT) refers to high-amplitude acoustic pulses generated outside the body and transmitted into tissue. “Extracorporeal” means the wave source is external.

The ISMST consensus statement on terms and definitions, issued on June 20, 2017, distinguishes focused or defocused extracorporeal shockwaves from radial pressure waves as separate categories. For focused or defocused shockwaves, the statement lists piezoelectric, electromagnetic, and electrohydraulic generation, with application by trained physicians. For radial pressure waves, it lists air pressure or electromagnetic coils, with application by trained physicians or, after prior physician diagnosis, by trained nurses or physiotherapists.

A 2025 independent international modified Delphi consensus, published in British Journal of Sports Medicine, took a supplementary terminological position separate from the ISMST framework: in common practice, ESWT is used to describe both focused and radial technologies, but only focused ESWT generates a true shockwave. The panel recommended that radial devices be referred to as “pressure wave therapy” or “radial pressure wave therapy”. This is an expert-panel recommendation about preferred clinical terminology, not a claim that the term “shockwave” has no historical or marketing currency in relation to radial devices.

Where Shockwave Therapy Comes From

Extracorporeally generated shock waves were first used in medicine to disintegrate kidney stones. The first reported patient treatment occurred in 1980 with a Dornier lithotripter prototype, and by 1983 a commercial unit had been developed.

The orthopedic application emerged from a different observation. During animal studies in the 1980s, researchers noted an osteoblastic response and enhanced fracture healing after shockwave exposure—a biological effect distinct from stone fragmentation. That finding generated interest in applying ESWT to musculoskeletal disorders, where the goal was not to disintegrate tissue but to induce repair.

This history matters because urological lithotripters and orthopedic pain devices followed separate regulatory pathways and carry different risk profiles. The orthopedic use case also established a precedent for using high-energy shockwaves to reach deep targets.

Focused Shockwaves and Radial Pressure Waves

Focused and radial technologies both deliver acoustic energy into tissue, but the distinction is not a simple “focused versus unfocused” binary. The ISMST 2017 statement groups focused or defocused extracorporeal shockwaves as one category, alongside radial pressure waves as a separate category. A shockwave generated by a focused device may converge at a target, distribute energy over a broader volume as a weakly focused field, or disperse more broadly as a defocused output; whether a tight focus is present is a property of the sound field and device design, not the sole criterion for whether the output qualifies as a shockwave.

What distinguishes a shockwave in the physical sense is the pressure waveform: a rapid rise in positive pressure followed by a tensile phase, with nonlinear propagation and high peak pressures. ISMST physics guidance describes the shock front as the pressure rising from 10% to 90% of peak positive pressure within a few nanoseconds. A radial pressure wave is generated by a different mechanism—typically compressed air or electromagnetic coils acting on a projectile or transmitter at the applicator surface—and propagates divergently outward rather than converging to a focal point.

The practical implication is that “non-focused” is not a synonym for “radial,” and “focused” alone does not confirm that a device generates a true shockwave without independent verification of the waveform and generation principle. True focused or defocused shockwaves can be produced by electrohydraulic, electromagnetic, or piezoelectric sources. Radial pressure waves are typically generated by ballistic or pneumatic mechanisms.

Why Terminology Matters in Clinical Practice

“Shockwave,” “radial shockwave,” “radial pressure wave,” and “acoustic wave” are often used interchangeably in marketing, implying equivalence where the physics does not. The 2025 Delphi panel recommended that focused shockwave therapy and radial pressure waves not be categorized as “high or low energy shockwaves,” because energy level and wave type are separate dimensions.

For clinical and procurement decisions, this distinction affects what the device can deliver to a given tissue depth, what FDA regulatory category the device falls into, and what training or credentialing the operator is expected to have. The ISMST 2017 statement describes application of focused or defocused shockwaves by trained physicians, and application of radial pressure waves by trained physicians or, after physician diagnosis, by trained nurses or physiotherapists. This is a professional-society recommendation, not a statement that every U.S. state legally mandates the same credentialing structure.

This article takes no position on which modality is clinically superior for any specific indication. What matters is that “shockwave therapy” as a category does not tell a clinician or buyer which physical technology is installed in the clinic.

Common Medical Applications: An Overview

In musculoskeletal care, ESWT has been studied most extensively for chronic tendinopathies and related bone-healing disorders. Published overviews describe applications including proximal plantar fasciitis, lateral epicondylitis, shoulder tendinopathy, patellar tendinopathy, Achilles tendinopathy, and non-union or delayed union.

In the United States, FDA authorization for orthopedic shockwave devices is indication-specific. In the FDA’s 2015 NBN reclassification docket, the agency noted that seven devices had received PMA authorization under product code NBN at that time, with six limited to chronic proximal plantar fasciitis and one for chronic lateral epicondylitis; the current inventory of NBN devices may differ from this historical count. FDA has stated that the evidence is inadequate to support broad “general orthopedic pain” claims beyond cleared or approved indications.

Whether a specific clinical use is cleared, approved, off-label, or investigational depends on the individual device and its Indications for Use; it cannot be inferred from the general category of “shockwave therapy.” This overview is not a treatment recommendation. Mechanism-level questions belong to a separate discussion: How Does Shockwave Therapy Work?

How to Identify the Technology Behind a Device

For clinicians and procurement teams, the practical question is not “Is this a shockwave device?” but “What type of acoustic pulse does this device generate, and what do its regulatory and technical documents state?”

Three categories of documentation are useful.

The Instructions for Use (IFU). The IFU should state the device’s technical classification, intended use, and specific contraindications and precautions. ISMST guidance consistently directs users to the device-specific IFU as the controlling document for safety and operation.

The regulatory pathway and product code. In the United States, a device may be cleared under 510(k), approved under Premarket Approval (PMA), or only registered and listed. These are not equivalent. Product code NBN—Generator, Shock-Wave, For Pain Relief—is a Class III category requiring PMA. A claim that a device is “FDA cleared” does not, by itself, establish that the device generates a true focused shockwave or that it carries a specific orthopedic indication.

The technical specification, not the marketing brochure. A device’s generation principle and sound-field characteristics should be documented in the technical file. The 2015 recommendation statement of the Conjoint Physics Working Group of ISMST and DIGEST noted that currently established shockwave parameters used to describe in-vitro or clinical conditions are insufficient, that the key effect of shockwaves on tissue is not yet known, and that comparison of device parameters is affected by measurement conditions. Manufacturer technical numbers should therefore be read as device-specific and measurement-condition-specific, not as universal specifications.

A practical verification sequence is: request the IFU, request the regulatory submission type and product code, request the generation principle and sound-field characteristics, and compare those documents against each other. If marketing language and technical documentation describe different technologies, the technical documentation is the relevant source.

Conclusion

Shockwave therapy is not a single technology with a fixed set of physical properties. It is a category name applied to devices that generate different acoustic waveforms, interact with tissue differently, and operate under different regulatory and training frameworks. The distinction between focused or defocused extracorporeal shockwaves and radial pressure waves is the most consequential technical divide within the category.

For a broader view of how these distinctions fit into clinical decision-making, session planning, safety boundaries, and U.S. For device-specific statements about SHOCKIS products—waveform type, generation principle, FDA status, and performance claims—confirm against the device IFU and regulatory documentation; do not infer technical or regulatory facts from category-level language.