An instrumented timed up and go: the added value of an accelerometer for identifying fall risk in idiopathic fallers

Abstract

The Timed Up and Go (TUG) test is a widely used measure of mobility and fall risk among older adults that is typically scored using a stopwatch. We tested the hypothesis that a body-fixed accelerometer can enhance the ability of the TUG to identify community-living older adults with a relatively high fall risk of unknown origin. Twenty-three community-living elderly fallers (76.0 ± 3.9 years) and 18 healthy controls (68.3 ± 9.1 years) performed the TUG while wearing a 3D-accelerometer on the lower back. Acceleration-derived parameters included Sit-to-Stand and Stand-to-Sit times, amplitude range (Range), and slopes (Jerk). Average step duration, number of steps, average step length, gait speed, acceleration-median, and standard-deviation were also calculated. While the stopwatch-based TUG duration was not significantly different between the groups, acceleration-derived TUG duration was significantly higher (p = 0.007) among the fallers. Fallers generally exhibited lower Range and Jerk (p < 0.01). While TUG stopwatch duration successfully identified 63% of the subjects, an accelerometer-derived three-measure-combination correctly classified 87% of the subjects. Accelerometer-derived measures were generally not correlated with TUG duration. These findings demonstrate that fallers have difficulty with specific TUG aspects that can be quantified using an accelerometer. Without compromising simplicity of testing, an accelerometer can apparently be combined with TUG duration to provide complementary, objective measures that allow for a more complete, sensitive TUG-based fall risk assessment.

Toward Automating Clinical Assessments: A Survey of the Timed Up and Go

“…It is evident that the TUG test is an important standardized test with several benefits, but the TUG is not without limitations: The duration measure is not always sensitive to falls risk in healthy older populations [35]-[39]. …”

The validity of assessing temporal events, sub-phases and trunk kinematics of the sit-to-walk movement in older adults using a single inertial sensor

“…A single IS, worn on the lower back, has successfully been used for analyzing sub-phases and trunk kinematics during chair rise (Giansanti and Maccioni, 2006;Millor et al, 2013;Schwenk et al, 2012;Van Lummel et al, 2012;Van Lummel et al, 2013;Weiss et al, 2011Weiss et al, , 2010 and have been validated against other instrumentation for the sit-to-stand task (Boonstra et al, 2006;Janssen et al, 2008;Zijlstra et al, 2012). But Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/jbiomech www.JBiomech.com the validity of using an IS during the biomechanically challenging sit-to-walk (STW) task, which is common in daily life, has not yet been investigated (Kouta and Shinkoda, 2008).…”

A feasibility study for the integration of 3D accelerometry in fall risk assessment

“…Relevant findings could be applied to improve the standardized processes and decision-support systems for falls risk management [4]. Future work of our research focuses on the refinement and validation of algorithms that allow the automatic extraction of parameters that provide an added-value compared to the usual scores -see [13] -as well as the development of an integrated accelerometry platform including webbased services and smart phone technology [14] for fall risk assessment and fall prevention to be deployed in a variety of clinical and non-clinical settings, including home.…”