Two ways of making a pressure wave

A radial device works by driving a projectile inside the handpiece against an applicator held on your skin. The impact sends a pressure wave outward from the tip of that applicator, and the wave loses energy as it spreads. Energy is therefore highest in the tissue closest to the surface and falls away with depth.

A focused device converges its energy instead of dispersing it. The wave is shaped so that it arrives at a point some distance below the skin, and the small volume of tissue at that point receives most of the energy rather than the tissue directly under the applicator face.

Both sit under the umbrella term extracorporeal shockwave therapy, which only means that the wave is produced outside the body and passed through the skin. The phrase covers both machines. That is where most of the confusion begins.

How deep the energy actually goes

This is the difference worth holding onto, because everything else follows from it.

The plantar fascia under the heel is close to the surface. You can put a thumb on the sore spot. The gluteal tendons at the side of the hip sit beneath a layer of muscle and fat that varies enormously between one person and the next, and finding them is a different problem entirely. A target you can press with a fingertip and a target you have to reach through several centimetres of tissue place different demands on a machine.

A device that concentrates energy near the surface has an obvious fit with the first. A device that can place its energy at a set depth has an obvious fit with the second. Neither statement makes one machine better than the other in general. They are answers to different questions.

What each type tends to be used for

In United Kingdom musculoskeletal practice, radial devices are the more common purchase and they are widely used on relatively superficial targets: the heel in plantar fasciitis, the outside of the elbow in tennis elbow, and the Achilles at the back of the ankle.

Focused devices appear more often where depth or precision is the constraint, which in practice means deeper tendon attachments and calcific deposits inside a shoulder tendon. Some clinics own both and choose between them by target. Many own one and treat everything with it.

None of this is a rule. It is a description of how the machines are commonly deployed, and a clinic may have perfectly good reasons for using the device it has on a target you might have expected the other one to handle.

Why most clinics own a single machine

A shockwave device is a capital purchase with a footprint in a treatment room and a consumables bill behind it. A clinic whose caseload is mostly heels, elbows and Achilles tendons has little practical reason to buy a second machine, and the training and protocol habits build up around whichever one arrives first.

That is not a criticism. It is simply the reason that asking “do you do shockwave” gets you a yes far more often than it gets you a useful answer.

Why a price list rarely names the device

Clinic websites and price lists tend to list the treatment, not the equipment. The word “shockwave” appears; the machine does not. From the outside the two treatments look identical, and the session you are quoted for could be either one.

For a superficial target this may make very little practical difference to you. For a tendon lying deep under other tissue it can be the whole question, because a device whose energy has largely dissipated before it reaches the target is not treating the target.

The questions worth asking before you book

Four questions, all of them reasonable, none of them awkward.

Which device type will be used on me, radial or focused? A clinic that treats with shockwave regularly will answer this without hesitating.

Why that one for my problem? You are listening for a reason connected to the depth and location of your target, not to what is in the room.

How many sessions, at what spacing, and at what energy level? Protocols differ between machines and between clinics, so the plan should be stated up front rather than decided week by week. The detail of a single session is worth reading before the first appointment.

What is running alongside it? A course of shockwave normally sits inside a loading rehabilitation programme rather than replacing one.

Where the published guidance stops short

NICE has looked at shockwave for several musculoskeletal problems. In interventional procedures guidance IPG311, now HealthTech guidance HTG200, on refractory plantar fasciitis, the conclusion reads: “The evidence on extracorporeal shockwave therapy (ESWT) for refractory plantar fasciitis raises no major safety concerns; however, current evidence on its efficacy is inconsistent. Therefore, this procedure should only be used with special arrangements for clinical governance, consent and audit or research.”

The wording in IPG313, now HTG201, on refractory tennis elbow is the same, and the Achilles guidance IPG571, now HTG426, reaches a comparably guarded position while adding that the evidence is limited in quality and quantity. The guidance on refractory greater trochanteric pain syndrome, IPG376, now HTG248, goes further in one respect: it requires that patients “should be informed about the possibility of pain during and after treatment, and the risk that symptoms may worsen”.

Here is the honest limit of all of it. None of these documents separates its conclusions by device type. They assess extracorporeal shockwave therapy as a category, and the trials underneath them were run on different machines with different protocols. So a study you read about a focused device does not automatically describe what a radial device will do to your heel, and the guidance offers no basis for preferring one over the other.

That cuts both ways. It means nobody can honestly tell you that the machine in front of them is the one the evidence supports, and it means the device question is best used to sharpen your understanding of the plan rather than to grade the clinic.

Where to start

The device question only becomes worth answering once someone has established that your problem is a sensible target in the first place. That is an examination, a history and a look at what loading you have already tried. If you want the wider picture first, the overview of shockwave therapy sets out which conditions it is used for and what the evidence supports.

Frequently asked questions

What is the difference between radial and focused shockwave therapy?

A radial device creates a pressure wave at the applicator tip that spreads outward and loses energy as it widens, so the energy is highest near the skin. A focused device converges its energy on a point at depth. The wave is generated differently and delivered to a different place.

How deep does shockwave therapy reach?

It depends on the device. Radial energy concentrates in the tissue closest to the skin and falls away as it travels. Focused energy is aimed at a target below the surface, and the operator sets that depth. This matters most for tendons lying under a layer of muscle or fat.

Is radial shockwave a real shockwave?

Radial devices produce a pressure wave rather than a converged wave, and clinics group both under the heading of extracorporeal shockwave therapy. The label on the price list is the same for both. The physics, the depth of delivery and the treatment protocol are not.

Which type of shockwave is used for plantar fasciitis?

Both types are used on the heel in United Kingdom practice. The NICE guidance on shockwave for plantar fasciitis does not separate its conclusions by device, so it offers no basis for preferring one machine. Ask the clinic which device they own and which protocol they follow.

Does it matter which shockwave machine a clinic uses?

It matters for interpreting the evidence you have read. A trial run on a focused device does not automatically speak for a radial one, and protocols vary between machines and between clinics. Knowing which you are booked for lets you ask sharper questions about the plan.