Balancing postural control and motor inhibition during gait initiation

Abstract

This study explores the link between cancelling a prepared gait initiation in response to sudden environmental changes and maintaining body stability. To address this, we developed a gait initiation version of the Stop Signal Task (SST), a widely used tool for evaluating motor inhibition during different forms of action control. To understand the relevance of postural control during gait initiation and suppression, we evaluated the underlying changes in anticipatory postural adjustments (APA). We report that specific trial-level variables, like the time to initiate or cancel stepping, interacted with biomechanical factors such as the center of mass displacement relative to the base of support, impacting performance. We identified a critical biomechanical threshold beyond which halting the movement became improbable. These findings underscore the tight connection between limb action control and overall body equilibrium, providing a framework within an established motor control paradigm. By incorporating biomechanical elements into this model, we demonstrate its efficacy for simulating complex real-life scenarios. This approach defines essential variables for studying neural correlations between action and postural control, guiding the development of tools for injury prevention and rehabilitation devices for individuals with movement and posture impairments, including those suffering of neurodegenerative disorders.