[1] Katholieke Univ Leuven, Acad Ctr Gen Practice, Kapucijnenvoer 33 Blok J, B-3000 Leuven, Belgium
[2] Radboud Univ Nijmegen, Med Ctr Nijmegen, IQ Healthcare, POB 9101, NL-6500 HB Nijmegen, Netherlands
[3] Univ Hosp Leuven, Div Rheumatol, Herestr 49, B-3000 Leuven, Belgium
[4] Katholieke Univ Leuven, Dept Rehabil Sci, Tervuursevest 101, B-3001 Heverlee, Belgium