Walking modality, but not task difficulty, influences the control of dual-task walking

Area of Science:

• Biomechanics
• Neuroscience
• Human Movement Science

Background:

• Stride-to-stride variability of stride time (STV) during dual-task gait is thought to reflect cognitive control allocation.
• Previous studies show conflicting effects of dual-tasking on STV between overground and treadmill walking.
• These discrepancies may stem from variations in dual-task difficulty across walking modalities.

Purpose of the Study:

• To compare the impact of overground versus treadmill dual-task walking on STV.
• To investigate whether differences in cognitive task performance or perceived difficulty explain modality-specific effects on STV.
• To elucidate modality-dependent gait control strategies under dual-task conditions.

Main Methods:

• 18 healthy adults participated in the study.
• Participants performed single-task (walking) and dual-task (walking while performing serial subtractions) conditions.
• Walking occurred overground and on a treadmill for 120s each.

Main Results:

• STV increased during overground dual-task walking.
• STV remained unchanged during treadmill dual-task walking.
• No significant differences were found in cognitive task performance or perceived task difficulty between the two modalities.

Conclusions:

• Gait control differs between overground and treadmill dual-task walking.
• These differences are not attributable solely to task difficulty.
• Modality-dependent control strategies likely underlie the observed variations in STV during dual-task locomotion.