Comparison of a Smartphone Balance Test and Commonly Used Balance Measures

Research Team Members David Mincberg, Johna Register-Mihalik, Brian Pietrosimone, Robert Lynall, Tim Mauntel

Why did you do this study?

In recent years there has been a large focus on concussion evaluation, diagnosis, and treatment. Following a head injury many different body systems are affected including those that are used to maintain balance. Because of this, balance testing is a vital part of concussion evaluation, and many competitive sports teams will include some form of this testing in their pre-participation medical screenings.

bess_troyThe Balance Error Scoring System, a common clinical balance test, has the subject hold several different stances while the tester counts “balance errors”. These errors include the subject losing their balance, coming out of the prescribed testing position, or opening their eyes during testing. While the BESS has been shown to be reliable and useful in detecting balance deficits following concussions, it requires a trained tester. Also the “errors” within the BESS are judged by the examiner and there is the possibility of variability across testers.

While there are other more objective or precise balance testing methods such as force plates or balance platforms, these methods are often expensive or difficult to interpret without extensive training. This makes them an unrealistic testing option for many high schools, small colleges, or clinics.

Smartphone accelerometers have shown potential in combining the convenience and value of traditional balance tests with the accuracy and objectivity of more advanced methods. One such test is the Sway Balance Test, which uses a smartphone held on the chest to measure body movement. It has been shown to be correlated with scores on the Balance Error Scoring System, a traditional clinical balance test, but few to no published studies have attempted to correlate the Sway Balance Test with force plate measures, which are considered a gold standard for testing balance.

smartphonebalanceWhat did you do and what did you find in this study?

We had participants complete several trials of the Sway Balance Test while recording their motion with a force plate. We then compared the scores from the Sway Balance Test with common force plate balance measures. We found that the Sway Balance Test was strongly correlated to the force plate data. Our preliminary analysis of the data suggest that the Sway Balance Test can be a useful tool for measuring static balance in healthy subjects and that more research is needed in a concussed sample.

How do these findings impact the public?

Our findings suggest that the Sway Balance Test, which uses smartphone accelerometers, may be a useful and accurate test of balance in health college aged individuals. While more research is needed before it is used to diagnose or serially track recovery following concussions, the Sway Balance Test could be an affordable, convenient, and easy to administer balance test.