Shock Wave Therapy for Sural Myofascial Pain Associated to Chronic Heel Pain

Inclusion Criteria: * Adult age (18 to 75 years) and written informed consent; * Unilateral heel pain of four weeks or longer duration; * Pain to digital pressure in the insertional area of the plantar fascia at the calcaneum; * Sonographic examination showing a plantar fascia thickness greater than 3.8mm (see procedures for details); * Concomitant presence of a sural myofascial pain syndrome (SMPS), diagnosed on the basis of the finding, at the physical examination, of trigger points of the gastrocnemius-soleus muscle complex, according to Travel and Simons' original description. Exclusion Criteria: * No corticosteroid injections or other physical therapies since the onset of the current pain episode (except pharmacological pain treatments and foot orthoses); * No general contraindication to shock wave therapy (pregnancy, bleeding disorders or anticoagulant drug usage, cancer in the focal area); * No clinical signs of lumbar radiculopathy at physical examination; * No ankle osteoarthritis, diagnosed on the basis of clinical and radiographic findings; * No previous fractures or surgery in the affected ankle and foot; * No rheumatologic diseases, no plantar fibromatosis