Funding for this research was provided by:
Danish Foundation for Chiropractic Research and Post Graduate Education, Denmark (A1507)
Received: 23 November 2020
Accepted: 29 March 2021
First Online: 9 April 2021
: The included patients were informed about the study and written consent was obtained. The data collection had obtained authorisation from the Danish Data Protection Agency (DPA) as part of the University of Southern Denmark’s institutional authorisation (GLA:D® Back cohort: DPA no. 2015–57-0008 SDU no. 17/30591, Test–retest cohort: SDU no. 10037). As treatment was not affected by participation in the study, under Danish law, this study did not need ethical approval <i>(Act on Research Ethics Review of Health Research Projects, October 2013, Sect. 14.2)</i> [CitationRef removed]<i>.</i> The conduct of the study complied with the Declaration of Helsinki.
: Not applicable.
: The authors have no financial or non-financial competing interests to declare.