Factors Contributing to Single- and Dual-Task Timed “Up & Go” Test Performance in Middle-Aged and Older Adults Who Are Active and Dwell in the Community

BACKGROUND: Dual-task Timed Up and Go (TUG) tests are likely to have applications different from those of single-task TUG test and may have different contributing factors. OBJECTIVE: The purpose of this study was to compare contributing factors of performance on single- and dual-task TUG tests. DESIGN: This investigation was a cross-sectional study. METHODS: Sixty-four community-dwelling adults older than 50 years of age were recruited. Interviews and physical examinations were performed to identify potential contributors to TUG performance. The time to complete the single-task TUG (TUGsingle) or the dual-task TUG, which consisted of completing the TUG while performing a serial subtraction task (TUGcognitive) or while carrying water (TUGmanual), was measured. RESULTS: Age, hip extensor strength, walking speed, general mental function, and Stroop scores for word and color were significantly associated with performance on all TUG tests. The hierarchical multiple regression models, without the input of walking speed, revealed different independent contributing factors for TUGsingle (MMSE, β=-0.32), TUGmanual (age, β=0.35), and TUGcognitive (Stroop word score, β=-0.40; MMSE, β=-0.31). LIMITATIONS: At least 40% of variance of the three TUG performances was not explained by common clinical measures, even when considering the factor of walking speed. However, this study has successfully identified some important contributing factors of different TUG performances, and other studies have reported similar figures on single-task TUG and dual-task gait performance. CONCLUSIONS: Although TUGsingle and TUGcognitive shared general mental function as a common factor, TUGmanual was uniquely influenced by age and TUGcognitive was uniquely influenced by focused attention. These results point to both common and unique contributing factors for single- and dual-task TUG performance, which pose important applications of combined use of these three TUG tests. Language: en