[1] Vrije Univ Brussel, Dept Hlth Sci & Med Sociol, Fac Med & Pharm, B-1090 Brussels, Belgium
[2] Katholieke Univ Leuven, Dept Rehabil Sci, Fac Kinesiol & Rehabil Sci, Louvain, Belgium
[3] Univ Hosp Pellenberg, Pellenberg, Belgium
[4] Fachklin Herzogenaurach, Herzogenaurach, Germany
[5] Katholieke Univ Leuven, LUDIT Ctr, Louvain, Belgium
[6] Rehaclin Zurzach, Zurzach, Switzerland
[7] Univ Nottingham, Inst Work Hlth & Org, Nottingham NG7 2RD, England