The Development and Validation of a Novel Smartphone Application to Detect Postural Instability

Area of Science:

• Biomechanics
• Human Movement Science
• Digital Health

Background:

• Traditional balance assessments are limited by cost, accessibility, and reliability.
• Smartphone inertial measurement units (IMUs) show potential for objective postural control evaluation.

Purpose of the Study:

• To develop and validate a novel smartphone application for assessing postural control.
• To compare the app's performance against research-grade posturography systems.

Main Methods:

• Twenty-two participants performed quiet stance tasks under varied visual (eyes open/closed) and surface (firm/foam) conditions.
• Data were collected simultaneously using a custom smartphone app, a motion capture system, and a force plate.
• Intraclass correlation coefficients and Pearson correlation coefficients were used for reliability and validity analysis.

Main Results:

• The smartphone app demonstrated strong reliability and validity when compared to gold-standard instruments.
• No significant differences in sway area or sway velocity were found between the smartphone app and research-grade systems.
• Significant main effects of visual and surface conditions on postural control were observed.

Conclusions:

• The developed smartphone application is a valid, sensitive, and accurate tool for measuring postural control.
• This technology can bridge the gap between at-home and clinical balance assessments, improving accessibility.
• The app offers a cost-effective and reliable alternative for balance evaluation.