Article

This study aimed to demonstrate the sensitivity of virtual reality (VR)/motion
tracking to detect global functional gait impairment resulting from an emulated
knee disability as a prelude to describing mobility changes following lower limb
injury/treatment. Participants walked in a figure-8 around two virtual posts
placed 6m apart while viewing the computer-generated environment in a
helmet-mounted display.
Three-dimensional position and orientation of the
participant's head were tracked and used to update the virtual scenes, measure
walking path and speed, and control task parameters with real-time feedback.
Participants walked with/without an emulated lower extremity disability (splint
preventing normal knee flexion). Participants performed the task at self-selected
Natural (NAT) speed providing a baseline measure of their turning speed and area.
Turning speed and area were then in turn maintained fixed (controlled speed, CS;
controlled path, CP) while the other variable was measured as a gait impairment
indicator. Different adaptive strategies were used to cope with the emulated
deficit during the NAT scenario: maintaining turning speed while altering path
geometry; decreasing turning speed while maintaining path geometry; and combining
the previous two strategies. This resulted, on average, in decreased turning
speeds and increased turning areas. The CS and CP manipulations respectively
generated even greater turning areas and more consistent speed decreases. The
three subtests acted as intertwined filters enabling the detection of functional
gait impairment in all subjects regardless of their adaptive strategies. This
proof-of-concept study demonstrated how VR/motion tracking technology can be used
to detect and quantitatively characterize global functional mobility impairment.
CI - Copyright 2010 Elsevier B.V. All rights reserved.

Langue : ANGLAIS