BACKGROUND: Cognitive deficits and gait problems are common and progressive in Alzheimer's disease (AD). Prescription of a 4-wheeled walker is a common intervention to improve stability and independence, yet can be associated with an increased falls risk.

OBJECTIVES: 1) To examine changes in spatial-temporal gait parameters while using a 4-wheeled walker under different walking conditions, and 2) to determine the cognitive and gait task costs of walking with the aid in adults with AD and healthy older adults.

METHODS: Twenty participants with AD (age 79.1±7.1 years) and 22 controls (age 68.5±10.7 years) walked using a 4-wheeled walker in a straight (6 m) and Figure of 8 path under three task conditions: single-task (no aid), dual-task (walking with aid), and multi-task (walking with aid while counting backwards by ones).

RESULTS: Gait velocity was statistically slower in adults with AD than the controls across all conditions (all p values

CONCLUSION: Learning to use a 4-wheeled walker is cognitively demanding and any additional tasks increases the demands, further adversely affecting gait. The increased cognitive demands result in a decrease in gait velocity that is greatest in adults with AD. Future research needs to investigate the effects of mobility aid training on gait performance.