Stride-time variability is related to sensorimotor cortical activation during forward and backward walking

Area of Science:

• Neuroscience
• Biomechanics
• Human Movement Analysis

Background:

• Previous studies indicate increased cortical activation in motor areas during backward walking compared to forward walking.
• Head movement during functional near-infrared spectroscopy (fNIRS) can introduce motion artifacts into the data.

Purpose of the Study:

• To investigate cortical activation in motor areas during both forward and backward walking.
• To concurrently measure head movement to assess its potential influence on fNIRS data.
• To test the hypothesis that greater motor area activation during backward walking correlates with increased head movement.

Main Methods:

• Participants walked forward and backward on a treadmill.
• Head movement was quantified using motion capture markers.
• Cortical activation was measured using fNIRS over motor areas.
• Stride-time was calculated using foot pressure sensors.

Main Results:

• No significant differences in head or body movement were found between forward and backward walking conditions.
• Backward walking resulted in significantly shorter stride-time but not increased variability compared to forward walking.
• After outlier removal, no significant differences in motor cortex activation were observed between walking conditions.
• A positive correlation was identified between stride-time variability and activation in the primary motor cortex.

Conclusions:

• Movement differences between forward and backward walking did not confound fNIRS results.
• Stride-time variability, particularly during forward walking, may be represented in the primary motor cortex.
• Further research is needed to fully understand the neural control of gait variability.