Article History
Received: 19 March 2018
Accepted: 3 July 2018
First Online: 12 July 2018
Competing Interests
: Nicholas B. Angstman and Hans-Georg Frank declare that no competing interests exist. Christoph Schmitz served (until December 2017) as a paid consultant for and received benefits from Electro Medical Systems (Nyon, Switzerland), the distributor of the Swiss DolorClast extracorporeal shock wave device. However, Electro Medical Systems had no any role in study design, data collection and analysis, decision to publish, or preparation of this manuscript. No other potential conflicts of interest relevant to this article were reported.