Extracorporeal shockwave therapy (ESWT) is a non-invasive treatment in which acoustic pressure waves are delivered through the skin into a painful musculoskeletal target, most often a chronic tendinopathy or plantar heel pain, as an adjunct to a loading programme rather than as a treatment on its own. It is commonly used in sport and exercise medicine (SEM) for selected persistent conditions, but efficacy and UK governance requirements vary considerably by indication, and current UK guidance restricts some uses to research and permits others only with special arrangements. Unlike injectable treatments it is delivered in repeated outpatient sessions without breaching the skin. This page covers how shockwave works and how focused and radial devices differ, what UK guidance says condition by condition, and how it is delivered safely.
Shockwave therapy delivers acoustic energy through the skin into the target tissue, and the first thing to be clear about is that two quite different devices share the name. Focused shockwave is generated electrohydraulically, electromagnetically or piezoelectrically, produces a true shock wave with a very steep pressure rise, and converges energy on a small focal zone that can be positioned at depth. Radial shockwave is generated pneumatically, by a projectile striking an applicator, and produces what is more accurately a radial pressure wave: energy is maximal at the skin surface and dissipates as it spreads outward and deeper, which suits more superficial targets. The key distinction is focal depth and wave characteristics rather than a simple contrast of higher against lower energy, and energy measures are not directly interchangeable between the two: focused treatment is commonly described using energy flux density, whereas radial treatment is more often described using applicator pressure, frequency and the number of impulses delivered. Focused treatment at higher energy can be painful, and local anaesthesia may be used for it, although it may reduce treatment effectiveness and is often avoided when treatment is tolerable.
The biological mechanisms are proposed rather than established, and it is safer in an exam to present them as such. The leading explanations are mechanotransduction, in which mechanical loading of cells stimulates cellular activity and matrix turnover; local vascular effects, including changes in blood flow and new vessel formation, noting that neovascularisation is not simply equivalent to beneficial healing; effects on pain signalling, including changes in substance P and in local nerve endings, which may explain a relatively rapid analgesic effect; and, in calcific tendinopathy specifically, physical disruption and subsequent resorption of the calcific deposit. Notably, shockwave is used in conditions characterised by degeneration rather than inflammation, which fits poorly with an anti-inflammatory explanation and better with a mechanotransduction and neurovascular account.
The UK guidance picture is more restrictive than the enthusiasm around shockwave suggests, and knowing the actual positions is examinable. For calcific tendinopathy of the shoulder, current guidance concludes that short-term safety raises no major concerns but that the evidence on efficacy is inadequate, so the procedure should be used only in the context of research; this is the most restrictive position and it is a common source of error, because the older literature often presents calcific disease as the best indication. For refractory plantar fasciitis, safety raises no major concerns but efficacy is inconsistent, so use requires special arrangements for clinical governance, consent and audit or research, with clinical governance leads informed, patients given clear written information about the uncertainty, and outcomes audited. For Achilles tendinopathy the evidence on efficacy is likewise inconsistent and limited, again requiring special arrangements. For refractory greater trochanteric pain syndrome, evidence on both safety and efficacy is limited in quality and quantity, and special arrangements apply. Refractory tennis elbow, meaning lateral elbow tendinopathy, is described as having inconsistent efficacy and also requires special arrangements. For patellar tendinopathy the evidence is mixed and no specific procedure guidance of this kind was identified.
The summary position is therefore that most indications require special arrangements, while calcific tendinopathy of the shoulder is restricted to research. Two practical principles follow. First, patient selection, device type and protocol all influence outcomes, so shockwave is reserved for chronic, correctly diagnosed conditions that have not settled with appropriate first-line care rather than used as an early or default response. Second, shockwave is delivered alongside, not instead of, a progressive loading programme, activity modification and attention to the factors that caused the problem; any symptom reduction it provides may help participation in rehabilitation, which is where the lasting benefit comes from. Patients should be told that a response typically takes several weeks and may continue to improve for some weeks after the course finishes, which prevents premature judgements of failure, and they should also understand the governance position that applies to their particular condition.
Delivery is straightforward but benefits from attention to detail. The target is identified clinically by palpating the point of maximal tenderness, and ultrasound may be used to confirm the target or to localise a calcific deposit. Coupling gel is applied so that acoustic energy transmits into the tissue rather than reflecting at the skin surface. Energy is usually titrated upwards within the session towards the level the patient can reasonably tolerate, since treatment is uncomfortable by nature. Protocols vary considerably: a commonly used course is three to five sessions at approximately weekly intervals, but single-session and multi-session regimens both exist, and the energy level, number of impulses and interval are set by the device, the condition and the local protocol rather than by a universal prescription. Local anaesthesia may be used for painful high-energy treatment, but it may reduce treatment effectiveness and is often avoided where treatment is tolerable, partly because patient feedback helps guide energy titration. Advice on relative rest afterwards is protocol-dependent rather than a fixed rule, and the loading programme continues alongside treatment.
Safety is good, with adverse effects that are mostly local and transient: pain during treatment, transient reddening of the skin, bruising, swelling and occasionally a temporary increase in symptoms. Contraindication lists are not universal and treatment must follow the device manufacturer instructions and local policy, but the commonly applied positions are worth knowing. Treatment is generally avoided where there is infection at the treatment site, malignancy in the treatment field, pregnancy over relevant areas, or where the beam would cross lung tissue. Caution or protocol-dependent considerations include anticoagulation or a bleeding disorder, which is a caution rather than an automatic contraindication, proximity to major neurovascular structures, immature growth plates in a skeletally immature patient, and recent corticosteroid injection at the site, where timing should follow device and local guidance. Avoiding non-steroidal anti-inflammatory drugs during a course is a theoretical, protocol-dependent consideration rather than an evidence-based requirement. On anti-doping, shockwave itself is a physical therapy and is not prohibited, whereas injectable glucocorticoids may carry in-competition restrictions depending on timing and route, which is one practical reason shockwave is considered in a competing athlete; any local anaesthetic, analgesic or accompanying injection must still be checked separately.
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