3 The procedure
3.1 Extracorporeal shockwave therapy (ESWT) is a non-invasive treatment in which a device is used to pass acoustic shockwaves through the skin to the affected area. Ultrasound guidance may be used to assist with positioning of the device. The shockwaves can be either focused or unfocused (often referred to as radial shock waves). The focused shockwaves are generated using electrohydraulic, electromagnetic or piezoelectric energy. The unfocused shockwaves are generated pneumatically.
3.2 Treatment protocols for ESWT vary according to the energy density and frequency of shockwaves. ESWT may be applied in a series of treatments or a single session. Local anaesthesia may be administered before treatment because high-energy ESWT (>0.12 mJ/mm2) can be painful; however, there is evidence that the use of local anaesthesia may adversely influence the outcome of ESWT. Low-energy ESWT (EFD ≤0.12 mJ/mm2) can be used repeatedly and does not need local anaesthesia.
3.3 The mechanism by which this therapy might affect tendinopathy is not known.