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Updated: Jan 26, 2026
08:12
Experimental Methods to Study Human Postural Control
Published on: September 11, 2019
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Asymmetric interjoint feedback contributes to postural control of redundant multi-link systems
Nathan E Bunderson1, Lena H Ting, Thomas J Burkholder
1Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA.
Journal of Neural Engineering
|September 18, 2007
Summary
Asymmetric feedback in limb control improves endpoint stability by 16% and reduces energy use by 21%. This neural strategy enhances coordination in redundant systems, like arms and legs.
Area of Science:
- Neuroscience
- Biomechanics
- Robotics
Background:
- Limb postural control relies on complex feedback networks involving muscles, reflexes, and neuronal structures.
- Previous research indicated a role for asymmetric heterogenic feedback, but its functional significance remained unclear.
Purpose of the Study:
- To investigate the hypothesis that asymmetric multi-joint feedback offers energetic and stability advantages for controlling kinematically redundant limbs.
- To compare the performance of symmetric versus asymmetric feedback strategies in maintaining limb endpoint position.
Main Methods:
- Utilized optimal control models of a planar limb with kinematic redundancy.
- Simulated limb endpoint control using both symmetric and asymmetric feedback mechanisms.
Main Results:
- Asymmetric feedback enhanced limb endpoint control by 16% compared to symmetric feedback.
- Energetic cost was reduced by 21% with asymmetric feedback.
- Interjoint coordination improved by 40% under asymmetric feedback, with proximal joint motion driving distal torque.
Conclusions:
- Asymmetric feedback plays a functionally significant role in coordinating redundant degrees of freedom for limb position maintenance.
- The observed asymmetric organization aligns with experimental measurements of heterogenic stretch reflex gains.
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