Every year, falls lead to hospitalisation or death for hundreds of thousands of elderly people in India and the world. But now a team of researchers from the University of North Carolina (UNC) at Chapel Hill and North Carolina (NC) State University has found evidence that virtual reality (VR) could be a big help in reducing such impairments.
The reasearchers, led by Jason R. Franz, an assistant professor in the joint UNC/NC State department of biomedical engineering, used a novel VR system to create the visual illusion of a loss of balance as study participants walked on a treadmill.
By perturbing their sense of balance in this way and recording their movements, Franz’s team was able to determine how the participants’ muscles responded.
“We were able to identify the muscles that orchestrate balance corrections during walking,” Franz said.
“We also learned how individual muscles are highly coordinated in preserving walking balance. These things provide an important roadmap for detecting balance impairments and the risk of future falls,” he added.
Young and healthy adults rely predominantly on the mechanical “sensors” in their feet and legs to give them an accurate sense of body position. So, healthy people usually have no trouble walking in the dark or with their eyes closed. But this sense of proprioception declines in the elderly, as well as in people who have neurodegenerative diseases.
“As each person walked, we added lateral oscillations to the video imagery, so that the visual environment made them feel as if they were swaying back and forth, or falling,” Franz said.
“The participants know they aren’t really swaying, but their brains and muscles automatically try to correct their balance anyway.”
The study findings gave important insights into the detailed mechanisms of walking balance control. The data also provide key reference measurements that could be used in future clinical procedures to detect balance impairments before they cause people to fall.
“We think there’s a big opportunity to use visual perturbations in a VR setting to reveal balance impairments that would not be detected in conventional testing or normal walking,” Franz said.
“The key is to challenge balance during walking, to tease out those impairments that exist under the surface,” he added.
The study findings were published recently in the journal Nature Scientific Reports.