Frailty Detection Using the Instrumented Version of the 30-s Chair Stand Test

Frailty syndrome is regarded as a major predictor of co-morbidities and mortality in older populations. Performance test such as the 30-s chair stand one (30-s CST) are a cornerstone for detecting early decline. However, predictions are normally more qualitative than quantitative. Latest advances in body-fixed sensors lead us to a new dimension of measurements, kinematic parameters that can furnish clinicians by objective information to outperform their diagnostics. In the case of the 30-s CST, it has been demonstrated that an instrumented version of the test is able not only to directly provide the actual outcome, the number of performed cycles, but also other kinematic parameters that can explain the movement performance. This instrumented version involves including an inertial unit which provides acceleration and angular velocity data. However, different steps are necessary to extract meaningful information from those rough data. Here, it is explained the full process to obtain kinematic parameters from the 30-s CST and the ones able to differentiate different frailty levels (i.e. Z-acceleration and Z-velocity peaks and positive and/or negative impulses). The main contribution is that this new quantitative information could be of special help in clinical diagnostics, home care services and/or in a fall risk prevention program.