Instrumented Timed Up and Go test: A reliable and valid tool for elderly with femur fracture

The Timed Up and Go (TUG) test, commonly used to predict falls, has been enhanced with an inertial sensor, creating the Instrumented TUG (iTUG). Its reliability has been evaluated in a few studies involving neurological and heterogeneous orthopaedic populations.

The aim was to assess the intra-rater, inter-rater, and test-retest reliability of the iTUG in patients with femur fractures and define an interpretative model of the iTUG and a discriminative one to detect patients at risk of fall.

201 inpatients with femur fractures underwent the iTUG test before discharge and a telephone follow-up at 1-month post-discharge to record falls. In a subgroup of 48 patients, iTUG data were used for assessing test-retest, intra-rater, and inter-rater reliability through Intra-class Correlation Coefficients. In the total sample, iTUG reliable variables were used for exploratory factor analysis and creating logistic regression models to identify the best predictive model for falls.

27/100 iTUG variables demonstrated "excellent" reliability; of those, 15 not-redundant variables were collected in a 3-factor model explaining 74 % of total variance. 92 % of patients completed the follow-up, and 5.5 % were classified as fallers. The fall risk model created with three iTUG variables showed an R²= 0.31, with an AUC= 0.91.

The iTUG test is a reliable tool for assessing individuals with femur fractures, with 27 highly reliable variables. The 3-factor model offers a focused framework for gait evaluation, while the fall-risk model highlights the predictive value of iTUG variables, indicating that fall risk in the elderly depends on multiple gait characteristics. This article was awarded the SIAMOC Best Paper 2024.