Post-Stroke Adaptation of Lateral Foot Placement Coordination in Variable Environments

Area of Science:

• Neuroscience
• Biomechanics
• Gait Analysis

Background:

• Individuals post-stroke often struggle with lateral foot placement adjustments, crucial for maintaining gait stability.
• Altered center of mass (COM) dynamics and stability requirements can impact gait strategies.

Purpose of the Study:

• To investigate how individuals with and without stroke adapt lateral foot placement (FP) in response to altered COM dynamics.
• To compare gait stability strategies between stroke survivors and healthy individuals under different walking conditions.

Main Methods:

• Participants walked on a treadmill in a Null Field (no external forces) and a Damping Field (opposing lateral COM velocity).
• Quantified the correlation between lateral COM state and lateral foot placement (FP), alongside step width mean and variability.

Main Results:

• Contrary to hypotheses, no significant difference in COM-FP correlation was found between the Damping and Null Fields.
• Individuals with stroke demonstrated weaker COM-FP correlations and wider step widths compared to controls.
• Both paretic and non-paretic limbs in stroke survivors showed weaker COM-FP correlations than controls.

Conclusions:

• The Damping Field did not significantly alter COM-FP correlations or step width in either group.
• Post-stroke, a shift towards a less specific lateral stabilization strategy, characterized by wider steps, is evident.
• This strategy appears less coupled to dynamic COM changes compared to individuals without stroke.