Control Mechanisms of Static and Dynamic Balance in Adults With and Without Vestibular Dysfunction in Oculus Virtual Environments.

Background: Deficits in sensory integration and fear of falling in complex environments contribute to decreased participation of adults with vestibular disorders. With recent advances in virtual reality technology, head-mounted displays are affordable and allow manipulation of the environment to test postural responses to visual changes.

Objectives: To develop an assessment of static and dynamic balance with the Oculus Rift and (1) to assess test-retest reliability of each scene in adults with and without vestibular hypofunction; (2) to describe changes in directional path and sample entropy in response to changes in visuals and surface and compare between groups; and (3) to evaluate the relation between balance performance and self-reported disability and balance confidence.

Design: Test-retest, blocked-randomized experimental design.

Setting: Research laboratory.

Participants: Twenty-five adults with vestibular hypofunction and 16 age- and sex-matched adults.

Methods: Participants stood on the floor or stability trainers while wearing the Oculus Rift. For 3 moving "stars" scenes, they stood naturally. For a "park" scene, they were asked to avoid a virtual ball. The protocol was repeated 1-4 weeks later.

Outcome: Anteroposterior and mediolateral center-of-pressure directional path and sample entropy were derived from a force plate.

Results: We observed good to excellent reliability in the 2 groups, with most intraclass correlations above 0.8 and only 2 at approximately 0.4. The vestibular group had higher directional path for the stars scenes and lower directional path for the park scene compared with controls, with large variability in the 2 groups. Sample entropy decreased with more challenging environments. In the vestibular group, less balance confidence strongly correlated with more sway for the stars scenes and less sway for the park scene.

Conclusion: Virtual reality paradigms can shed light on the control mechanism of static and dynamic postural control. Clinical utility and implementation of our portable Oculus Rift assessment should be further studied.

Level Of Evidence: II.