A functional tracking task to assess frontal plane motor control in post stroke gait

Area of Science:

• Neuroscience
• Biomechanics
• Gait Analysis

Background:

• Maintaining upright posture during gait relies on frontal plane control of foot placement.
• Previous studies assessed step width and variability post-stroke only during normal walking.
• Stroke often causes limb-specific sensory-motor control deficits.

Purpose of the Study:

• To investigate limb-specific motor control in the frontal plane during a gait tracking task in stroke survivors.
• To characterize post-stroke frontal plane sensory-motor control under varying task complexities.
• To evaluate a novel step width tracking paradigm for clinical assessment.

Main Methods:

• Chronic stroke (n=15) and control (n=10) subjects performed a gait tracking task with static foot placement targets.
• Subjects walked at self-selected speeds, tracking targets and completing a free walking trial.
• Analysis focused on step width and foot placement variability and error, comparing limb performance.

Main Results:

• Stroke subjects exhibited significantly reduced control over step width and foot placement variability compared to controls.
• Task complexity, specifically reduced target step width, increased variability in stroke survivors.
• Affected limb foot placement variability also increased with task complexity.

Conclusions:

• Stroke-induced sensory-motor integration changes result in inter-limb differences in frontal plane motor variability.
• Gait tracking task complexity exacerbates motor control deficits in stroke survivors.
• The step width tracking paradigm offers a reproducible clinical metric for gait assessment and rehabilitation outcomes.