Competing interests
DB
MB has received funding for studies on rehabilitation from the German Research Foundation and the Federal Ministry of Labor and Social Affairs, as well as the Federal German Pension Insurance and the Pension Insurance North, Berlin-Brandenburg and Knappschaft-Bahn-See. DB is a staff member of the rehabilitation center where the intervention is being performed. He has developed the program and is involved in the treatment. DB has received funding for studies on rehabilitation from the Association for the Promotion of Rehabilitation Research in Hamburg, Mecklenburg-Vorpommern and Schleswig-Holstein, the German Pension Insurance North, and the Institute for Quality Management in Health Care. LW is a staff member of the rehabilitation center and is involved in the treatment. FTS and LMR declare that they have no competing interests.