[1] Leiden Univ, Med Ctr, Dept Rehabil Med, NL-2300 RC Leiden, Netherlands
[2] Univ Twente, Inst Biomed Technol & Tech Med MIRA, Lab Biomech Engn, NL-7500 AE Enschede, Netherlands
[3] Vrije Univ Amsterdam, Med Ctr, Dept Internal Med, Sect Gerontol & Geriatr, Amsterdam, Netherlands
[4] Delft Univ Technol, Dept Biomech Engn, Delft, Netherlands
[5] Vrije Univ Amsterdam, Med Ctr, Dept Rehabil Med, Amsterdam, Netherlands