Author: Nollet, F., Beelen, A., Prins, M., de Visser, M., Sargeant, A., Lankhorst, G., de Jong, B.
Journal/Publisher: Archives of Physical Medicine and Rehabilitation
Issue: Feb 1999: 80(2): 136-43
http://www.archives-pmr.org/article/S0003-9993(99)90110-7/abstract