Accelerometry applications and methods to assess standing balance in older adults and mobility-limited patient populations: a narrative review

Abstract

Accelerometers provide an opportunity to expand standing balance assessments outside of the laboratory. The purpose of this narrative review is to show that accelerometers are accurate, objective, and accessible tools for balance assessment. Accelerometry has been validated against current gold standard technology, such as optical motion capture systems and force plates. Many studies have been conducted to show how accelerometers can be useful for clinical examinations. Recent studies have begun to apply classification algorithms to accelerometry balance measures to discriminate populations at risk for falls. In addition to healthy older adults, accelerometry can monitor balance in patient populations such as Parkinson's disease, multiple sclerosis, and traumatic brain injury. The lack of software packages or easy-to-use applications have hindered the shift into the clinical space. Lack of consensus on outcome metrics has also slowed the clinical adoption of accelerometer-based balance assessments. Future studies should focus on metrics that are most helpful to evaluate balance in specific populations and protocols that are clinically efficacious.

Keywords: Accelerometry; Accessibility; Balance; Fall risk.

Fig. 1

A Diagram of a mass-spring system and Hooke’s Law, where $F$ is force, $k$ is the spring constant, $x$ is the displacement, $m$ is the mass, and $a$ is the acceleration B Simplified diagram of a capacitive micro-electromechanical accelerometer where $m$ is the mass, $k_1$ and $k_2$ are springs, and $C_1$ and $C_2$ are capacitors.

Fig. 2

Diagram of the single-link (left), the double-link (center), and the triple-link (right) biomechanical models.