title: 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.
abstract: BACKGROUND
  Dual-task Timed "Up & Go" (TUG) tests are likely to have applications different from those of a single-task TUG test and may have different contributing factors.
  
  
  OBJECTIVE
  The purpose of this study was to compare factors contributing to performance on single- and dual-task TUG tests.
  
  
  METHODS
  This investigation was a cross-sectional study.
  
  
  METHODS
  Sixty-four adults who were more than 50 years of age and dwelled in the community were recruited. Interviews and physical examinations were performed to identify potential contributors to TUG test performance. The time to complete the single-task TUG test (TUGsingle) or the dual-task TUG test, which consisted of completing the TUG test 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. Hierarchical multiple regression models, without the input of walking speed, revealed different independent factors contributing to TUGsingle performance (Mini-Mental Status Examination score, β=-0.32), TUGmanual performance (age, β=0.35), and TUGcognitive performance (Stroop word score, β=-0.40; Mini-Mental Status Examination score, β=-0.31).
  
  
  CONCLUSIONS
  At least 40% of the variance in the performance on the 3 TUG tests was not explained by common clinical measures, even when the factor of walking speed was considered. However, this study successfully identified some important factors contributing to performance on different TUG tests, and other studies have reported similar findings for single-task TUG test and dual-task gait performance.
  
  
  CONCLUSIONS
  Although the TUGsingle and the TUGcognitive shared general mental function as a common factor, the TUGmanual was uniquely influenced by age and the TUGcognitive was uniquely influenced by focused attention. These results suggest that both common and unique factors contribute to performance on single- and dual-task TUG tests and suggest important applications of the combined use of the 3 TUG tests.
authors.affiliation: H-Y. Chen, PT, PhD, School of Physical Therapy, Chung Shan Medical University, Taichung, Taiwan, and Physical Therapy Room, Chung Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Hui-Ya
authors.initials: HY
authors.lastname: Chen
authors.affiliation: P-F. Tang, PT, PhD, School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Room 325, Floor 3, No. 17, XuZhou Road, ZhongZheng District, Taipei, Taiwan; Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan; Neurobiology and Cognitive Science Center, National Taiwan University Hospital; and Physical Therapy Center, National Taiwan University Hospital. pftang@ntu.edu.tw.
authors.forename: Pei-Fang
authors.initials: PF
authors.lastname: Tang
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D057187:Independent Living; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D013647:Task Performance and Analysis