Article

An impaired ability to allocate attention to gait during dual-task
situations is a powerful predictor of falls. OBJECTIVE: The primary purpose of
this study was to examine the relative contributions of participant
characteristics and motor and cognitive factors to the ability to walk while
performing cognitive tasks. The impact of cognitive task complexity on walking
also was examined.
DESIGN: A cross-sectional, exploratory study design was used.
METHODS: Seventy-seven community-dwelling older adults with a mean (SD) age of
75.5 (5.8) years completed comprehensive testing. Participant characteristics
were assessed via questionnaires. The motor test battery included measures of
strength (force-generating capacity), gait speed, and static and dynamic balance.
The cognitive abilities test battery assessed psychomotor and perceptual speed,
recall and working memory, verbal and spatial ability, and attention (sustained,
selective, and divided). Time to walk while performing 4 cognitive tasks was
measured. In addition, dual-task costs (DTCs) were calculated. Multiple
hierarchical regressions explored walking under dual-task conditions. RESULTS:
The ability to walk and perform a simple cognitive task was explained by
participant characteristics and motor factors alone, whereas walking and
performing a complex cognitive task was explained by cognitive factors in
addition to participant and motor factors. Regardless of the cognitive task,
participants walked slower under dual-task conditions than under single-task
conditions. Increased cognitive task complexity resulted in greater slowing of
gait: gait DTCs were least for the simplest conditions and greatest for the
complex conditions. Limitations Walking performance was characterized by a single
parameter (time), whereas other spatiotemporal parameters have been related to
dual-task performance. However, this type of measurement (timed performance) will
be easy to implement in the clinic. CONCLUSIONS: Two factors-participant
characteristics and motor abilities-explained the majority of variance of walking
under dual-task conditions; however, cognitive abilities also contributed
significantly to the regression models. Rehabilitation focused on improving
underlying balance and gait deficits, as well as specific cognitive impairments,
may significantly improve walking under dual-task conditions.

Langue : ANGLAIS