Bidirectional locomotion induces unilateral limb adaptations.

Area of Science:

• Neuroscience
• Biomechanics
• Motor Control

Background:

• Motor learning enables lifelong skill acquisition, crucial for rehabilitation after neurological injury.
• Adaptation, the initial phase of motor learning, involves transient adjustments to environmental demands.
• Locomotor adaptation is commonly studied using split-belt treadmills.

Purpose of the Study:

• To investigate if bidirectional walking (BDW) on a split-belt treadmill can induce short-term gait adaptations.
• To explore the effects of BDW on gait kinematics and motor learning.

Main Methods:

• Twelve healthy volunteers participated in a single-session experiment.
• The protocol included normal walking (NW), followed by four blocks of BDW, and concluded with NW.
• Body kinematics and ground reaction forces were recorded throughout the experiment.

Main Results:

• Participants rapidly adapted to BDW, showing reduced step lengths in both legs.
• Only the backward-walking leg displayed aftereffects upon returning to NW, indicating unilateral adaptation.
• Significant kinematic changes were observed in hip extension and pelvis tilt, with inter-individual variability.

Conclusions:

• BDW induces unilateral locomotor adaptations despite bilateral gait changes.
• Findings provide novel insights into locomotor control mechanisms and spinal central pattern generator (CPG) organization.
• This research contributes to understanding motor learning and adaptation in human locomotion.