Härkäpää, Kristiina1,∗; Järvikoski, Aila1; Mellin, Guy1; Hurri, Heikki1; Luoma, Jarmo1
1Rehabilitation Foundation, SF-00410 HelsinkiFinland
∗Correspondence to: Kristiina Härkäpää, Lic. Ph., Rehabilitation Foundation, Pakarituvantie 4, SF-00410 Helsinki, Finland.
Submitted April 26, 1990; revised July 23, 1990; accepted December 14, 1990.