Antoni Morral, Gerard Urrútia, Ignasi Gich, Reme Ruiz, Xavier Bonfill
Blanquerna School of Health Sciences, Ramon Llull University, 08025 Barcelona, Spain. E-mail: antonimf@blanquerna.url.edu
DOI: 10.2340/16501977-2516

Objective: To determine whether the appearance of a radial extracorporeal shock wave device affects clinical outcomes in chronic plantar fasciitis.
Study design: Randomized controlled parallel assessor-blinded clinical trial.
Material and methods: A total of 135 patients were assigned to 3 groups: group I, standard radial extracorporeal shock wave device; group II, standard radial extracorporeal shock wave device modified to give a more sophisticated appearance; group III, standard radial extracorporeal shock wave device modified to give a more austere appearance. The radial extracorporeal shock waves emitted by the 3 devices were identical. Primary outcome was foot function, measured with the Foot Function Index. Secondary outcomes were pain at different times, measured with a visual analogue scale, and plantar fascia thickness, measured with ultrasound.
Results: All variables decreased significantly from baseline assessment, in all 3 groups and at all time-points: 1, 2, 4 and 14 months after the last session (p < 0. 001). There were no significant differences between groups for any of the variables assessed.
Conclusion: Device appearance had no statistically significant influence on clinical outcomes in patients with chronic plantar fasciitis treated with radial extracorporeal shock wave therapy.

The context and environment in which treatment is administered is highly relevant. Context variables are perceived and interpreted by patients and can generate positive or negative expectations. Such expectations may influence the therapeutic outcome. This study assessed whether a contextual element, such as the external appearance of a shock wave device, influenced clinical outcomes in patients with chronic plantar fasciitis. Three shock wave devices were compared: a standard device; a sophisticated device; and an austere device. The only difference between the devices was their external appearance. The shockwaves emitted by the 3 devices were identical. No differences were found between the 3 devices for any of the variables assessed. Health professionals and future research into the therapeutic encounter context should focus more on patient–therapist interactions than on the appearance of devices.