Optimal feedback control as a theory of motor coordination

  title={Optimal feedback control as a theory of motor coordination},
  author={Emanuel Todorov and Michael I. Jordan},
  journal={Nature Neuroscience},
A central problem in motor control is understanding how the many biomechanical degrees of freedom are coordinated to achieve a common goal. An especially puzzling aspect of coordination is that behavioral goals are achieved reliably and repeatedly with movements rarely reproducible in their detail. Existing theoretical frameworks emphasize either goal achievement or the richness of motor variability, but fail to reconcile the two. Here we propose an alternative theory based on stochastic… 
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  • M. Kawato
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    Current Opinion in Neurobiology
  • 1999
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Goal-equivalent joint coordination in pointing: affect of vision and arm dominance.
The results of this study suggest that the nervous system uses a control strategy that provides for a range of goal-equivalent, rather than unique, joint combinations to stabilize the values of important task-related variables, while selectively restricting joint configurations that change these values.
The Role of Inertial Sensitivity in Motor Planning
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Formation and control of optimal trajectory in human multijoint arm movement
The idea that the human hand trajectory is planned and controlled in accordance with the minimum torquechange criterion is supported by developing an iterative scheme, with which the optimal trajectory and the associated motor command are simultaneously computed.
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  • A. Kuo
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