Shockwave therapy delivers short pulses of acoustic or mechanical energy into tissue from a device placed against the skin. It is noninvasive and has been studied for several musculoskeletal conditions, including knee osteoarthritis.
The difficult part for patients is that "shockwave" does not describe one standardized treatment. Focused shockwave, radial pressure wave, EPAT, and SoftWave may be discussed together in advertising even though the underlying technology and treatment fields are not identical.
This page concerns native-knee osteoarthritis. If you already have a knee replacement and it hurts, start with the Pain After Knee Replacement pathway.
Compare symptom-focused knee treatments
Why the terminology matters
The International Society for Medical Shockwave Treatment distinguishes focused or defocused extracorporeal shockwaves from radial pressure waves because they are produced differently and create different sound fields.
| Term | What it usually means | What a patient should clarify |
|---|---|---|
| Focused ESWT | Shockwave energy concentrated into a defined treatment region; systems may use electrohydraulic, electromagnetic, or piezoelectric generation | Device, treatment depth, energy, target, and protocol |
| Radial pressure wave | A pressure wave generated at the applicator that spreads outward; often marketed as radial shockwave | Whether the published evidence being quoted actually used a radial system |
| ESWT | Extracorporeal shockwave therapy; often used broadly, but studies may involve very different devices | Focused, radial, broad/defocused, or another technology? |
| EPAT | A proprietary commercial term used for extracorporeal pulse activation technology; some EPAT systems are radial pressure-wave systems and the broader platform also includes other shockwave technologies | Exact device and energy technology |
| SoftWave | A commercial brand whose manufacturer describes an electrohydraulic, broad-focused/parallel shockwave system | Do not assume evidence from a different focused or radial system automatically applies |
A clinic saying "we offer shockwave" is therefore only the beginning of the description.
What is shockwave trying to change?
For knee osteoarthritis, shockwave treatment is being used as a symptom-focused, nonoperative treatment. Proposed biological effects include changes in local pain signaling, blood flow, and tissue responses.
The clinically important question is whether a specific protocol improves pain and function.
Shockwave therapy should not be presented as a proven way to regrow substantial lost knee cartilage, reverse bone-on-bone arthritis, correct alignment, or stabilize an unstable knee.
What do randomized studies show?
Several randomized studies provide a genuine clinical signal.
A placebo-controlled trial of 63 patients with mild-to-moderate knee osteoarthritis found that four weeks of low-dose ESWT improved pain and function more than sham treatment at short-term follow-up.
A 2020 randomized sham-controlled study of 104 patients found greater improvement with radial pressure-wave treatment in pain, walking, function, and several other outcomes through three months.
A 2022 randomized study directly comparing focused and radial treatment found improvement with both approaches, with greater short-term improvement in several pain and function outcomes after focused shockwave.
These studies are encouraging, but they do not establish one universal protocol. Devices, energy settings, treatment locations, number of sessions, co-treatments, and follow-up periods vary.
The main unanswered questions are:
- Which technology works best for knee osteoarthritis?
- Which patients are most likely to respond?
- What dose and treatment target should be used?
- How durable is the benefit beyond the first few months?
- Can results from one device be generalized to another?
What is treatment like?
Treatment is typically performed in an office with a handpiece placed against the skin using coupling gel.
A session involves a series of pulses directed to one or more treatment areas. A course may involve several sessions separated by days or about a week, but there is no single knee-osteoarthritis protocol used by every clinician or study.
Temporary soreness during or after treatment can occur.
Who might consider discussing it?
Shockwave may be reasonable to discuss when:
- Knee osteoarthritis is the likely main source of symptoms.
- The patient wants to continue nonoperative treatment.
- Exercise, activity modification, medication, bracing, or injections have not provided enough relief or are not suitable.
- The patient understands that the goal is symptom improvement rather than structural reconstruction.
- The cost and uncertainty are acceptable.
A markedly swollen, hot, unstable, newly injured, or rapidly worsening knee deserves appropriate diagnostic evaluation rather than simply adding another pain treatment.
How to compare clinics
Ask for more detail than the brand name.
- Is your system focused shockwave, radial pressure wave, broad/defocused shockwave, or another technology?
- What is the exact device?
- What published knee-osteoarthritis study is closest to the protocol you use?
- Where around the knee is treatment applied?
- How many sessions do you recommend, and why?
- What benefit should I realistically expect?
- How long does improvement usually last in your practice?
- What is the total out-of-pocket cost?
- What happens if the treatment does not help?
KneeLife does not currently treat every clinic advertising "shockwave" as equivalent. Technology and source verification matter.
Key sources
- International Society for Medical Shockwave Treatment terms, definitions, and recommendations
- International Society for Medical Shockwave Treatment explanation of focused and radial wave physics
- 2019 randomized placebo-controlled low-dose ESWT trial
- 2020 randomized sham-controlled radial pressure-wave trial
- 2022 randomized focused-versus-radial study
- CuraMedix description of radial pressure wave / EPAT and focused ESWT
- SoftWave manufacturer technology description