Adjusting gait step-by-step: Brain activation during split-belt treadmill walking.

Area of Science:

• Neuroscience
• Motor Control
• Human Locomotion

Background:

• Human walking typically involves a steady-state gait pattern.
• Split-belt treadmills alter gait by driving each belt at different speeds.
• The neural mechanisms controlling these gait adaptations are not fully understood.

Purpose of the Study:

• To investigate brain activity during split-belt treadmill walking.
• To identify brain regions involved in adapting locomotion.
• To understand the neural basis of gait flexibility.

Main Methods:

• Ten young adults participated in two conditions: tied-belt control and continuous split-belt speed adjustment.
• ¹⁸F-fluorodeoxyglucose (¹⁸FDG) positron emission tomography (PET) measured whole-brain glucose metabolism.
• PET imaging assessed brain activation during different walking conditions.

Main Results:

• Continuous split-belt walking increased activity in the supplementary motor areas (SMA), posterior parietal cortex (PPC), anterior cingulate cortex, and anterior lateral cerebellum.
• Decreased activity was observed in the posterior cingulate and medial prefrontal cortex during split-belt walking.
• PPC, SMA, and PFC activation correlated with gait variability and cadence.

Conclusions:

• A distinct brain network, including sensorimotor integration and attention areas, supports adaptable human locomotion.
• These findings highlight specific neural regions governing the flexibility of the human locomotor plan.
• The brain actively fine-tunes gait to maintain stable and adjustable walking patterns.