Does surface slope affect dual task performance and gait? An exploratory study in younger and older adults

Area of Science:

• Gerontology
• Biomechanics
• Cognitive Neuroscience

Background:

• Dual-tasking, performing a cognitive and motor task simultaneously, can alter gait stability.
• Gait stability is influenced by cognitive and postural capacity, and task difficulty.
• The impact of increased walking task difficulty on gait stability during dual-tasking in different age groups is not well understood.

Purpose of the Study:

• To investigate how increased walking task difficulty affects gait stability in younger and older adults during dual-tasking.
• To compare gait stability changes between age groups when performing a challenging audiospatial task concurrently with walking on varied terrain.

Main Methods:

• Ten younger and ten older healthy adults walked on a treadmill at preferred speeds.
• Walking conditions included level and downhill slopes, with and without a difficult audiospatial task.
• Gait stability was assessed using step width and mediolateral center of mass displacement; secondary task performance was measured by response time and accuracy.

Main Results:

• Older adults exhibited increased step width and maintained mediolateral center of mass displacement when dual-tasking downhill compared to walking downhill alone.
• Younger adults maintained step width during dual-tasking but showed reduced mediolateral center of mass displacement on a level surface during dual-tasking.
• Increased walking difficulty led older adults to widen their step, enhancing stability.

Conclusions:

• Older adults adapt their gait by increasing step width to improve stability when faced with greater walking difficulty during dual-tasking.
• Younger adults demonstrate different compensatory strategies, potentially indicating greater inherent gait stability or different attentional resource allocation.
• Age-related differences exist in gait adaptation strategies under challenging dual-task conditions.