Shockwave Therapy: Examining its Benefits and Side Effects

Are you looking for reliable information about extracorporeal shockwave therapy?

In recent years, I have noticed an increasing number of physiotherapy clinics investing in expensive devices for shockwave therapy. People often reach out to me to inquire about the effectiveness and benefits of this treatment and seek my opinion.

Shockwave therapy is frequently recommended by sports physicians, general practitioners, surgeons, osteopaths, and physiotherapists, especially for athletes experiencing tendonitis, injuries, or sports-related pain.

A growing number of internet users, including physiotherapists, patients, doctors, surgeons, and athletes, are seeking information on the effectiveness of shockwave machines. They are also interested in session costs, potential side effects, pain levels, and more.

I have updated my knowledge on this topic by reviewing recent scientific international publications. Enjoy your reading 🙂!

What is radial or focal shockwave therapy?

Initially, shockwaves were used in urology, particularly for the destruction of kidney stones. Shockwave therapy has been used for musculoskeletal problems for about 20 years, primarily in Germany 🇩🇪 and Bulgaria 🇧🇬.

Definition of extracorporeal shockwave therapy

Shockwave therapy is a treatment that has the following characteristics:

1. It is non-invasive, applied to the skin without the need for penetration into the body.
2. A shockwave is applied to the skin, which is a physical, mechanical energy.
3. This physical energy triggers biological reactions at the cellular level.

Studies have been conducted on both deceased and living non-human animals to better understand the potential mechanisms of shockwaves. It appears that they can stimulate osteogenesis, the growth of bone cells, in animals (Auersperg, 2020). They also seem to accelerate the production of pro-inflammatory cells, which in turn generate the production of immune cells (Rosso, 2015).

⚠️ However, these are only hypotheses about the mechanism of action of shockwaves, based solely on animal studies.

Difference between radial and focal shockwaves

Sometimes a distinction is made between:

• Radial shockwaves, considered low-energy.
• Focused shockwaves, considered high-energy.

⚠️ However, current recommendations from scientific literature show that this distinction is incorrect and should be abandoned (Schmitz, 2015). This is because there is no consensus in the literature regarding what is considered “low-energy” and “high-energy,” with each author and practitioner setting their own threshold.

Therefore, it doesn’t matter whether you receive shockwaves classified as radial or focused.

Physical therapy: shock wave treatment

It is rare for shockwave therapy to be the only thing a patient receives or performs during a physiotherapy session. It can take place at the beginning, middle, or end of the PT session, as it has little importance.

Specifically, the time dedicated to shockwave therapy is organized as follows:

1. The physiotherapist positions the person in a comfortable position that also allows easy access to the area of the body being treated.
2. The physiotherapist selects an appropriate applicator head for the device based on the treatment area.
3. They set the desired parameters. Clinical studies have shown that this does not have an influence on the outcomes, although it is generally recommended to administer treatment once a week, with 2000 pulses per session, at the highest intensity tolerable by the patient (Schmitz, 2015).
4. The shockwave is applied by the professional to the treatment area for a few minutes, while also applying gel. It is advised not to apply local anesthesia, as it could potentially decrease the effectiveness of the treatment (Schmitz, 2015).
5. Once the application is complete, the patient can continue with their session and activities without any specific precautions.

Is shockwave therapy painful?

Most of the time, shockwave therapy sessions are not painful. However, certain areas of the body with thin skin may be more sensitive. The sensation is more akin to tingling or warmth. It is therefore referred to as a sometimes unpleasant sensation rather than pain.

Pain is an adverse effect reported by a minority of patients in certain clinical studies.

In such cases, the pain is reported during the session and possibly in the hours following it, but not for an extended period of time.

Does shockwave therapy really work?

We would like a simple, clear, and quick answer to the question: “Is shockwave therapy effective?” Yes or no? The problem is that this question is too vague to be answered so simply, even though we often come across websites or articles claiming it to be a “highly effective” treatment.

Let’s see how we can address this. First, we need to understand for which conditions shockwave therapy is most commonly used by physical therapists. It’s possible that it is effective for certain conditions but not for others.

What is shockwave therapy used for?

The different conditions for which physiotherapists use shockwave therapy include:

• Tendinopathy (such as gluteal and supraspinatus tendinitis, calcific tendinitis)
• Epicondylitis
• Plantar fasciitis and heel spur
• Periostitis

And specific body parts, such as:

• Heel (Achilles tendon) (torn achilles, etc.)
• Foot
• Ankle
• Shoulder

Does this mean that the technique is effective for these problems? We first need to clarify what we mean by “effective.”

How to determine if shockwave therapy is beneficial?

How can we determine if shockwave therapy is truly effective? It is not enough to test it on one person: even if that person feels better after a few days or weeks, we cannot attribute it solely to shockwave therapy without considering other factors (the passage of time, rest, placebo effect, etc.).

That’s why its effectiveness needs to be tested on a large number of people, comparing their progress with others who received different treatments or no treatment at all. This is the principle of a comparative trial (also known as a controlled trial).

Here are the common treatment comparisons used for evaluating shockwave therapy:

• No specific intervention
• Muscle strengthening (often eccentric exercises)
• Placebo shockwave therapy (pretending to activate the machine without actually delivering the therapy or using very low intensity)
• Stretching exercises
• Anti-inflammatory medication (oral or topical)
• Massage therapy
• Injections of corticosteroids, anesthetics, platelet-rich plasma, hyaluronic acid, or other substances
• Cryotherapy
• Laser therapy
• TENS machine
• Immobilization with a splint
• General physiotherapy without specifying the exact modalities

It is also important to define what “getting better” means.

• Does it mean being completely pain-free?
• Having reduced pain?
• Being able to return to sports activities?
• Showing no abnormalities in radiological or other tests?
• And does this improvement occur 2 weeks after starting the treatment? 2 months? 6 months?

Only with a clear understanding of these answers can we assess the potential benefits of shockwave therapy.

Furthermore, the effectiveness of shockwave therapy is commonly evaluated based on the following criteria:

1. Pain Morning stiffness
2. Mobility and joint range of motion
3. Spasticity
4. Ability to perform daily or sports activities without discomfort

Typically, evaluation occurs at the following time points:

• 2 weeks after starting the treatment
• 2 months after starting the treatment
• 6 months after the completion of treatment
• 12 months after the completion of treatment
• 2 years after the completion of treatment

Lastly, we must not overlook an important aspect: the presence of unintended negative effects (also known as side effects or adverse effects). If we believe a therapy has an effect, it can have both positive and negative outcomes. This applies not only to medications.

Ideally, every study on shockwave therapy should document any potential side effects that occur in treated patients compared to those in other groups.

The image below summarizes all the pathologies for which shockwave therapy has been tested on several dozen individuals, comparing it to another therapy (or no therapy).

What benefits can be expected using shockwave therapy machine?

What can we conclude in a concise manner from the results of all these studies?

• When shockwave therapy is more effective than other techniques or doing nothing at all, the effect size is not very large. For example, people who receive shockwave therapy experience a decrease in their pain rating on a scale of 1 to 10 by 1 to 3 points compared to those who did not receive it.
• There are numerous studies that conclude that shockwave therapy is no more effective than other commonly used treatments in physiotherapy, including less expensive options such as stretching, strengthening, and gradual return to activities.
• The results of the two most methodologically rigorous systematic reviews (performed by the Cochrane Collaboration) both conclude that shockwave therapy probably does not improve pain and function compared to a placebo. Shockwave therapy has also been tested for conditions for which physiotherapists rarely suggest its use (spasticity, erectile dysfunction, pelvic pain).

The risk of bias in the studies is often high or uncertain. This means that the studies likely overestimate the effect of shockwave therapy. For example, the individuals assessing the effectiveness of the treatments are not blinded, meaning they are aware of which treatment the patients received. The therapists themselves are often not blinded either, even when administering sham shockwave treatments.

Lastly, we must consider the issue of publication bias. Researchers and scientific journals tend to publish studies that show the superior effectiveness of a treatment more often than studies that find no difference between two treatments.

How often should you do shockwave?

In general, shockwave therapy is administered in multiple sessions, usually spaced out over several weeks. For certain conditions, such as chronic tendonitis or plantar fasciitis, it is common to receive one or more sessions per week for a total of three to six weeks.

However, the exact number of sessions and the interval between them can vary.

How long do benefits of shockwave therapy last?

The duration of the benefits of shockwave therapy for musculoskeletal disorders, considering that its effectiveness is not superior to placebo, can vary and may not be long-lasting.

Since the evidence suggests that shockwave therapy may not provide significant clinical benefits beyond a placebo effect, the effects of the treatment may be limited in terms of long-term outcomes.

Possible side effects of shockwave therapy

Can shockwave therapy cause damage? Most people undergoing shock wave therapy experience no side effects. In some people, minor and short-lived undesirable effects may occur, including:

• pain
• skin redness
• bruising/hematoma
• bleeding.

It is difficult to provide an accurate frequency of these problems as many clinical trials do not systematically record the side effects of shock wave therapy.

Less commonly, a more serious side effect has been observed:

• tendon rupture (especially in individuals over 65 years of age)

Finally, there are potential but theoretical adverse effects that have not been reported in the literature:

• loss of blood supply
• death of bone tissue.

The main side effects of shock wave therapy are pain and skin redness.

What is the cost of shockwave therapy?

Session prices

In the United States, shockwave therapy sessions provided by physical therapists or healthcare professionals typically range from $50 to $500 per session. These prices are approximate and can vary significantly.

Coverage can vary depending on the insurance plan and the specific medical necessity criteria. Some insurance plans may provide partial or full coverage for shockwave therapy, while others may not cover it at all. It’s recommended to contact your insurance provider directly to inquire about coverage and reimbursement details.

Purchase prices

Shockwave therapy devices can range in cost depending on the brand, model, and features. The prices for purchasing a shockwave therapy device ranging from several thousand dollars to tens of thousands of dollars.

Sometimes, shockwave machines can be found at lower prices, typically sold for a few hundred dollars.

The brands of devices often owned by physical therapists include Storz Medical, Chattanooga, Nitro, and Zimmer Enpuls, which can range in price from 4,000 to 15,000 dollars for new devices sold by medical or paramedical distributors.

Such price variations raise questions: what justifies such a price difference? Considering the low or nonexistent effectiveness of shockwave therapy, is such an investment worthwhile? Additionally, studies show that there is no specific type of shockwave device that is more effective than others (electromagnetic, electrohydraulic, piezoelectric) (Schmitz 2015).

It is also possible to find used shockwave devices.

How to find a physiotherapist with shockwave therapy equipment?

As you may have understood, shockwave therapy does not significantly improve your pain or speed up your recovery. There is no study showing that athletes recover faster with the use of shockwave therapy, regardless of the musculoskeletal condition being treated in physical therapy.

Even with this information available, some people may still wish to try shockwave therapy. Here are the options available to you:

1. Find a physical therapy clinic equipped with a shockwave device. To do this, prioritize contacting clinics focused on “sports physiotherapy.” To find them, you can use a search engine and enter keywords such as “sports physio + your location” or “shockwave therapy + your location.”
2. Find a healthcare facility or another professional in your area who is equipped with a shockwave device. This could be a sports physician, cosmetic surgeon, or even an osteopath. The advantage of turning to physiotherapists is that these healthcare professionals can potentially guide you towards other effective rehabilitation methods.
3. Invest in a shockwave device yourself. Shockwave devices can be found for around $349. Alternatively, you can purchase them from specialized sellers of physiotherapy or rehabilitation equipment. Prices can easily exceed $1,000 or even $10,000. You can also find used shockwave devices on forums dedicated to physiotherapists or through online marketplaces like CraigList or Mercari.

Shockwave therapy: my opinion

It is important, I believe, to keep this in mind: you undergo a few sessions of shockwave therapy, and your health condition improves? You feel like you’ve finally found an effective treatment?

That’s great for you! However, this doesn’t prove that the improvement is solely due to shockwave therapy.

Why? Because numerous other factors could have interfered and explained this improvement.

For instance, it could be:

• The cumulative effect of all the small things and treatments you have implemented.
• The improvement may be simply attributed to the passage of time gradually healing your problem.
• It is also possible that investing time and money in pursuing this therapy had a positive effect, independent of the machine’s actual impact.

That’s why we would need high-quality clinical studies to prove the effectiveness of shockwave therapy.

Unfortunately, despite 25 years of experimental studies, there is no indication of a distinct and significant efficacy of extracorporeal shockwaves compared to other simpler and less expensive treatments.