Different functional networks underlying human walking with pulling force fields acting in forward or backward...

Area of Science:

• Neuroscience
• Biomechanics
• Motor Control

Background:

• Force field walking is used in clinical gait training.
• Different motor strategies underlie walking with forward vs. backward force fields.

Purpose of the Study:

• To investigate if adaptation to one force field direction transfers to the opposite direction.
• To determine if adaptation to opposing force fields is maintained independently.

Main Methods:

• Subjects walked on a split-belt treadmill under forward and backward force fields.
• Adaptation was assessed using braking and propulsive impulses of ground reaction forces.

Main Results:

• Adaptation to a force field was only partially transferred to the opposite direction.
• Adaptation to one force field direction was rarely washed out by subsequent exposure to the opposite force field.

Conclusions:

• Neural networks controlling walking in opposing force fields may function independently.
• This independence suggests distinct neural mechanisms for controlling gait under different force field conditions.