Quantifying Static and Dynamic Stability Using Mobile Sensors

Quantifying Static and Dynamic Stability Using Mobile Sensors Balance disorders burden over 35% of Americans, causing substantial impact on quality of life due to psychological and physical hardships associated with poor balance. Balance disorder can affect all individuals, and range in seriousness from slight dizziness to the inability to safely walk from place to place. Elderly adults are most susceptible to the dangers of poor balance, where injuries from falling are a prevalent and grave concern. Balance disorders are often assessed only after the event of a fall or injury, warranting the need for a readily available, at home balance assessment. In addition, current methods of testing balance are prohibitive in cost, accessibility and time. This study explores the potential of using a smart phone as a portable, low cost balance assessment tool. This study uses non-linear analysis, through the calculation of sample entropy during static standing, and maximum Lyapunov exponent’s during dynamic walking. Participants in this study have performed the six stances of the Balance Error Scoring System (BESS) test for a standing balance examination, and a six-minute walking trial for dynamic data collection. A smart phone strapped to the waist of the participant collects continuous acceleration data. In total, 11 subjects have been collected and analyzed. Compared to similar studies which use lab grade accelerometers, data analysis has shown similar outcomes, with inaccuracies attributed to the low-quality accelerometer of the smart phone. Results of the study have proven that modern smartphone technology is promising is providing accurate and reliable sensory data collection