Received: 17 March 2020
Accepted: 4 August 2020
First Online: 15 August 2020
Ethics approval and consent to participate
: The study was approved by the local ethical review board (Ethikkommission FB 05, Goethe University Frankfurt), number: 2015–33.
: Not applicable.
: DN is a member of the editorial board of BMC Musculoskelatal disorders. The authors declare no competing interests.