Comparisons of the validity and reliability of two smartphone placements for balance assessment using an accelerometer-based application

Abstract

Purpose: To establish the proper smartphone placement between two positions (thoracic vs. lumbar) for balance assessment using an accelerometer (ACC)-based application.

Methods: Eighteen young adults were recruited. The smartphone was attached at either of the T3-5 and L3-5 vertebra levels. Acceleration data were recorded using an ACC application for the Android operating system. Each participant was asked to perform: static balance (the Modified Clinical Test of Sensory Interaction in Balance (MCTSIB) and a single-leg stance (SL) test) and dynamic balance (a limit of stability (LOS) test). Three-dimensional (3D) motion analysis was also recorded.

Results: The thoracic level had a higher correlation between smartphone ACC and 3D motion analysis during the MCTSIB and SL tests than the lumbar level. Conversely, the lumbar level had a higher correlation than the thoracic level for the LOS test. The test–retest reliabilities showed a high to excellent reliability, except the lumbar level during the MCTSIB had moderate reliability.

Conclusions: For the static balance tests using the smartphone ACC, thoracic placement appears to be better than lumbar placement. In contrast, for the dynamic balance test, lumbar placement is more appropriate than thoracic placement.

Keywords:

• 3D motion analysis
• accelerometer
• posturography
• dynamic balance
• mobile application

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported in part by the Research Fund of the Faculty of Allied Health Sciences, Chulalongkorn University [Grant # AHS-CU 61001] and the 90th Anniversary of Chulalongkorn University Fund (Ratchadaphiseksomphot Endowment Fund).