“It can help us identify, using quantifiable metrics, who is most at risk for suffering a fall or a balance-related driving impairment.”
To understand and quantify what goes wrong when people suffer from balance disorders, researchers must first understand what normal balance looks like in healthy people. Taking a huge step in that direction, a team including San Diego State University neuromechanics researcher
Harsimran “Sim” Baweja recently published the largest-ever comprehensive database of normative balance.
The massive study measured “postural sway”—that is, how much the body naturally leans to and fro when standing still—in more than 16,000 people in the United States and Canada, ages five to 100.
“Measuring postural sway is like a thermometer for balance,” Baweja explained. “It can help us identify, using quantifiable metrics, who is most at risk for suffering a fall or a balance-related driving impairment.”
Baweja and study lead author
Daniel Goble, formerly at SDSU and now at Oakland University in Rochester, Michigan, used a technology they themselves developed to collect these measurements. In conjunction with the SDSU Zahn Innovation Center, Goble developed the
BTrackS Balance Plate, a portable and sensitive force plate that can easily plug into a laptop or tablet.
During the BTrackS Balance Test, study participants attempted to stand as still as possible for one minute on the BTrackS balance plate. Force plates in the board detected and recorded tiny shifts in weight as the person unconsciously swayed just a little bit. An algorithm then converted this amount of sway into an anonymized index score.
For the past four years, Baweja, Goble and their graduate students have been collecting balance data. They also collected anonymous data from groups around the country who have purchased their own BTrackS board. The researchers
announced the database last month in the journal
Physical Therapy.
People with balance disorders, such as those who have suffered a concussion or the elderly, tend to have higher sway scores. One way to diagnose this disorder is to compare a person’s sway before and after a traumatic event like a concussion—a protocol Baweja and Goble promote for use in athletic competitions. But to study abnormal balance in broader populations, it was necessary to collect large swaths of data to determine an average sway score.
It’s not quite as precise as measuring an individual’s before-and-after sway scores, but according to Baweja, it’s miles better than the traditional method: a clinician asking a patient to stand still and eyeballing whether they are shifting around more than usual.
The new database represents a big step toward developing quantifiable metrics for tracking balance. For instance, clinicians could compare their patients’ sway against the population average to see whether his or her balance merits further investigation.
“Let’s stop eyeballing things and saying, ‘I think your balance is off,’” said Baweja. “If we’re going to move forward into clinical relevance, the field needs truly objective measures, not just eyeball-ometry.”