Using video animation to assess mobility in older adults.
BACKGROUND
Although the importance of the context of task performance in the assessment of mobility in older adults is generally understood, there is little empirical evidence that demonstrates how sensitive older adults are to subtle changes in task demands. Thus, we developed a novel approach to examine this issue.


METHODS
We collected item response data to 81 animated video clips, where various mobility-related tasks were modified in a systematic fashion to manipulate task difficulty.


RESULTS
The participants (N = 234), 166 women and 68 men, had an average age of 81.9 years and a variety of comorbidities. Histograms of item responses revealed dramatic and systematic effects on older adults' self-reported ability when varying walking speed, use of a handrail during ascent and descent of stairs, walking at different speeds outdoors over uneven terrain, and carrying an object. For example, there was almost a threefold increase in reporting the inability to walk at the fast speed compared with the slow speed for a minute or less, and twice as many participants reported the inability to walk at the fast speed outdoors over uneven terrain compared with indoors.


CONCLUSIONS
The data provide clear evidence that varying the contextual features and demands of a simple task such as stair climbing has a significant impact on older adults' self-reporting of ability related to mobility. More work is needed on the psychometric properties of such assessments and to determine if this methodology has conceptual and clinical relevance in studying mobility disability.
Department of Health and Exercise Science, Wake Forest University, P.O. Box 7868, Winston-Salem, NC 27109, USA. marshap@wfu.edu
Anthony P
AP
Marsh
Edward H
EH
Ip
Ryan T
RT
Barnard
Yue-Ling
YL
Wong
W Jack
WJ
Rejeski
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001168:Arthritis / Q000503:physiopathology; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000503:physiopathology; D005260:Female; D006331:Heart Diseases / Q000503:physiopathology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D008297:Male; D009068:Movement; D013647:Task Performance and Analysis; D014741:Video Recording; D016138:Walking