Project Summary
The risk of falling increases with age, occurring each year in approximately 28-35% of people over 65 years of
age and increasing to 32-42% for people 70 years and over. Finding effective methods capable of detecting a
manifestation of impaired balance when there are no apparent signs of instability can thus improve the quality
of life of billions of people, reducing their fall risk, helping them prevent injuries, and maintain independence.
One of the fundamental limitations is that postural instability is rarely identified before a fall occurs, and only
then does a patient receive appropriate attention for improving balance. Such an advancement would help to
limit falls by indicating a need for preventative interventions such as rehabilitation or the use of assistive
technologies. The long-term goal of this work is twofold. The first is to determine if unique instability predicted
by mathematical models of human balance when neuromuscular control changes exist experimentally. The
second is to determine if subtle manipulation in virtual reality can be used to detect balance impairment and
the mechanisms behind such deficiencies. These goals are tested in two Specific Aims. In Specific Aim 1, we
will determine the perception of magnified and delayed postural deviations through virtual reality will lead to a
unique oscillatory instability for healthy participants with no previous signs of postural instability. This will
provide an understanding of the relationship increased neuromuscular feedback gain and delay have on
postural instability, allowing insight into the unique instability encounter through these mechanisms. In Specific
Aim 2, we will determine if the perception of attenuated postural deviations through virtual reality will lead to a
leaning instability for healthy participants with no previous signs of postural instability. This will provide an
understanding of the relationship decrease neuromuscular feedback gain have on postural instability, allowing
insight into the unique instability encountered through this mechanism. Investigation of these Specific Aims will
allow us to determine if the amount of manipulation to the perception of postural deviation in virtual reality to
induce instability correlates with clinical assessment methods. The underlying hypothesis of this Specific Aim is
that individuals with a low fall-risk will require the largest amount of manipulation in VR with the opposite being
true for individuals with a high fall-risk and will directly correlate with fall-risk as assessed by the Berg Balance
Scale and the Timed Up and Go test. This proposed work will lead to an increased fundamental understanding
of the mechanisms responsible for postural instability and their relationship to factors such as age, sex, height,
weight, fall-risk, fall history, and fear of falling. An additional benefit is the development of an object method for
assessing balance and provides critical insights into deficient mechanisms of postural control, a significant
advancement towards improved methods of fall prevention. Identifying an individual's proximity to postural
instability could lead to personalized training, more efficiently addressing their specific needs. The
development of virtual reality strategies to assess and rehabilitate postural instability could help to reduce the
substantial economic cost associated with falls.