Validity of smartphone-based postural control assessment for chronic ankle instability

Abstract

Decreased postural control ability are commonly found in who suffer from chronic ankle instability. Identifying decreased postural control ability could help to make an appropriate rehabilitation plan and reduce the possibility of recurrent ankle sprain. With newly emerging technologies, utilizing the inherent sensors in smartphones may provide a method of easy-access and portable alternative for postural control assessment. The purpose of this study is to establish the level of validity of smartphone-based postural control assessment. Thirty-eight participants, with at least one ankle instable, were assessed using the smartphone application developed for recording built-in accelerometer data. Zenfone 3 smartphone was positioned at the middle of the shin. Participants completed 4 trails of single leg stance balance test each in eyes opened and eyes closed conditions, while simultaneously recording data from force platform, which was considered as the golden standard of postural sway assessment tool. Correlation between smartphone and force platform was evaluate using SPSS 20.0, and statistical significance was set as alpha < 0.05. Pearson's correlation coefficient of eyes opened condition in medial-lateral direction between smartphone-based assessment and force platform was 0.700 ( P < 0.005), and 0.759 ( P < 0.005) in anterior-posterior direction. Pearson's correlation coefficient of eyes closed condition in medial-lateral direction between smartphone-based assessment and force platform was 0.734 ( P < 0.005), and 0.803 ( P < 0.005) in anterior-posterior direction. Our results show that the smartphone assessment has good correlation compared to the force platform when recording the performance of single leg stance balance test. The smartphone-based assessment shows potential as an easy-use and accessible tool to assess postural control ability.