On the interlimb coordination and synchronization during gait.

Area of Science:

• Neuroscience
• Biomechanics
• Human Locomotion

Background:

• Human locomotion relies on precise interlimb coordination.
• Understanding interlimb pathways is crucial for gait control, especially in altered sensory conditions.
• External support and limited vestibular feedback challenge natural gait coordination.

Purpose of the Study:

• To investigate the role of interlimb pathways in coordinating and synchronizing leg movements.
• To analyze responses to unilateral perturbations during walking with external body weight support and reduced vestibular input.
• To characterize the influence of perturbation timing on the contralateral limb's response.

Main Methods:

• Utilized the novel MIT-Skywalker device for gait therapy, providing external body weight support and torso stabilization.
• Subjects walked on a split-belt treadmill where one belt's speed was unexpectedly altered during the stance phase.
• Recorded leg kinematics and analyzed phase-response curves (PRCs) to quantify interlimb coordination.

Main Results:

• Unilateral leg perturbations elicited responses in the contralateral limb, demonstrating interlimb communication.
• The timing of the perturbation significantly influenced the magnitude and nature of the contralateral limb's response.
• Phase-response curves revealed distinct coordination patterns between the legs under altered sensory conditions.

Conclusions:

• Interlimb pathways play a significant role in synchronizing leg movements during human locomotion, even with reduced sensory feedback.
• The timing of external perturbations is a critical factor in modulating interlimb coordination.
• Findings from this study using the MIT-Skywalker provide insights into gait control mechanisms and potential therapeutic interventions for gait disorders.