The effectiveness of radial extracorporeal shock wave therapy (rESWT), sham-rESWT, standardised exercise programme or usual care for patients with plantar fasciopathy: study protocol for a double-blind, randomised, sham-controlled trial

BACKGROUND: Plantar fasciopathy is a common cause of plantar heel pain, with a reported prevalence of up to 10%. The choice of best practice in these patients is debated. Two randomised studies reported that radial extracorporeal shock wave therapy is effective, but a meta-analysis concluded that due to methodological limitations, the evidence is questionable. There are few studies reporting the effect of exercise programs with high-load strength training, despite widespread use. The objective of this placebo-controlled, observer-blinded and partly patient blinded trial is to compare rESWT, sham-rESWT, standardised exercise programme and usual care for alleviating heel pain at 6 and 12 months follow-up. METHODS/DESIGN: A double-blind, randomised, sham-controlled trial is conducted at a hospital outpatient clinic of physical medicine and rehabilitation. Patients with chronic (> 3 months) pain due to plantar fasciopathy, aged 18 to 70 years old, are eligible for inclusion in the trial. Patients will be randomly allocated in 1:1 ratio to receive rESWT, sham-rESWT, standardised exercises or usual care. The sample size is estimated to 200 patients, 50 in each group. rESWT or sham-rESWT will be given once a week for 3 weeks. A physiotherapist will supervise the exercises, with a total of 8 sessions over 12 weeks. The patients in the usual care group will receive information, advice and foot orthosis only. All patients, regardless of group, will receive the same information and get an individual customised foot orthosis made by an orthopaedic technician. The primary outcome measure is heel pain intensity during activity in the last week, using a numeric rating scale (NRS, 0 to 10) at the 6 months follow-up adjusted for baseline pain intensity. The secondary outcomes are at the 6- and 12-month follow-up and include Foot Functional Index Revised Short Version (FFI-RS), Patient Global Impression of Change Scale (7-point Likert scale), RAND-12 Health Status Inventory (RAND-12), NRS during rest and NRS during activity (12 months). The patients receiving rESWT/sham-rESWT and the outcome assessor will be blinded to the group assignment. DISCUSSION: This trial is designed in order to provide results important for future clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov NCT03472989. Registered on 14 March 2018