Article

Research has shown that moving targets help Parkinson's disease (PD) patients
improve their arm movement while sitting. We examined whether increasing the
speed of a moving ball would also improve standing postural control in PD
patients during a virtual reality (VR) ball-catching task. Twenty-one PD patients
and 21 controls bilaterally reached to catch slow-moving and then fast-moving
virtual balls while standing. A projection-based VR system connected to a
motion-tracking system and a force platform was used. Dependent measures included
the kinematics of arm movement (movement time, peak velocity), duration of
anticipatory postural adjustments (APA), and center of pressure (COP) movement
(movement time, maximum amplitude, and average velocity). When catching a fast
ball, both PD and control groups made arm movements with shorter movement time
and higher peak velocity, longer APA, as well as COP movements with shorter
movement time and smaller amplitude than when catching a slow ball. The change in
performance from slow- to fast-ball conditions was not different between the PD
and control groups. The results suggest that raising the speed of virtual moving
targets should increase the speed of arm and COP movements for PD patients.
Therapists, however, should also be aware that a fast virtual moving target
causes the patient to confine the COP excursion to a smaller amplitude. Future
research should examine the effect of other task parameters (e.g., target
distance, direction) on COP movement and examine the long-term effect of VR
training.
CI - Copyright (c) 2013 Elsevier B.V. All rights reserved.

Langue : ANGLAIS