For Clinicians And Researchers.
Physiotherapy May 2015 Volume 101, Supplement 1, Page e189
Rapid stepping time on ‘virtual’ objects correlates with measures of balance and fear of falling in elderly individuals
Y. Laufer, A. Burstin, R. Brown, O. Korsensky, Y. Hutzler
Background: Falls among the elderly are a global health concern. Rapid stepping in response to an external cue, which is necessary to avoid a fall because of a slip or trip, is often impaired in the elderly. Studies indicate that step execution tests can identify elderly individuals at risk for falls. However, while a force platform is considered the gold standard for assessing step execution, this equipment is often expensive, difficult to interpret, and not feasible in a clinical setting. Virtual Reality (VR) platforms which are used increasingly within the rehabilitation setting as intervention modalities can also be harnessed for motion assessment.
Purpose: To determine the correlation between the duration of rapid stepping responses towards ‘virtual’ objects assessed by a clinical VR system (SeeMe Rehabilitation System), and clinical measures of balance and fear of falling.
Methods: Sixty ambulatory elderly individuals (mean age (SD) 88.2 (5.0) years), residing in a senior living retirement center participated in this study. Subjects completed a demographic questionnaire, and the Activities Specific Balance Confidence (ABC) questionnaire. The Mini-Best test and the Timed Up and Go Test (TUG) (a component of the Mini-Best test) were used to assess balance. Next, the subjects participated in a single, virtual reality session with the SeeMe Rehabilitation System, which is a clinician-controlled exercise system based on Microsoft's Kinect technology. Subjects were asked to perform multiple steps as quickly as possible on a ‘virtual ball’ placed on a 'virtual floor’. Stance position determined the foot used and the direction of the steps (forward, backward or sideways) during three, 60-second test periods. Spearman correlations were calculated, with p≤0.05 considered significant.
Results: Significant correlations were determined between the step tests in all directions and the Mini-Best test, the TUG and the ABC. Correlations between the Mini-Best test and the forward and backward steps (ρ=-0.52) were higher than the correlation between the Mini-Best test and the sideward steps (ρ=-0.32). Similarly, correlations between the TUG and the forward and backward steps (ρ= 0.46 and ρ= 0.42, respectively) were somewhat higher than the correlation between the TUG and
the sideward steps (ρ= 0.37). A different pattern emerged regarding the correlation between the ABC and steps in different directions, as the strongest correlation was for backward steps (ρ=-0.46), whereas correlations with the forward and backward steps were both ρ=-0.35.
Conclusions: The duration of rapid steps in all directions, as determined with Microsoft’s Kinect technology incorporated within a VR platform, is moderately to strongly associate with commonly used clinical measures of balance performance in the elderly. While the rapid execution of forward and backward steps is more strongly associated with balance performance than sideways steps, backwards stepping is more strongly associated with fear of falling.
Implications: The VR rehabilitation platform can be used by clinicians to assess balance capabilities as part of an intervention program.
Keywords: balance; elderly; stepping; virtual reality; Timed Up and Go Test; Mini-Best test