Optimal feedback control as a theory of motor coordination

@article{Todorov2002OptimalFC,
  title={Optimal feedback control as a theory of motor coordination},
  author={Emanuel Todorov and Michael I. Jordan},
  journal={Nature Neuroscience},
  year={2002},
  volume={5},
  pages={1226-1235}
}
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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References

SHOWING 1-10 OF 75 REFERENCES
A computational description of the organization of human reaching and prehension
TLDR
A novel fusion of optimization and control is introduced to the field, simultaneously explaining movement kinematics and model-based integration of afferent and efferent signals.
Internal models for motor control and trajectory planning
  • M. Kawato
  • Biology, Psychology
    Current Opinion in Neurobiology
  • 1999
Optimality in human motor performance: ideal control of rapid aimed movements.
TLDR
The present conceptual framework provides insights into principles of motor performance, and it links the study of physical action to research on sensation, perception, and cognition, where psychologists have been concerned for some time about the degree to which mental processes incorporate rational and normative rules.
Goal-equivalent joint coordination in pointing: affect of vision and arm dominance.
TLDR
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
TLDR
The results suggest that the sensitivity of the arm to perturbations, as determined by its inertial stability, is taken into account in the planning process.
Formation and control of optimal trajectory in human multijoint arm movement
TLDR
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.
Understanding sensorimotor feedback through optimal control.
TLDR
This work adopts the convention of using "controller" to designate a device that formulates a set of commands intended to change the state of a system, which commands are executed openloop, i.e., without modification during the task.
An optimal control model for analyzing human postural balance
  • A. Kuo
  • Engineering
    IEEE Transactions on Biomedical Engineering
  • 1995
TLDR
A human sensorimotor control model, compatible with previous work by others, was assembled that incorporates linearized equations and full-state feedback with provision for state estimation, and produces a control that reasonably matches experimental data.
Identifying the control structure of multijoint coordination during pistol shooting
TLDR
The UCM principle applied to relative gun orientation captures the structure of the motor control system across different parts of joint configuration space as the movement evolves in time, and suggests a specific control strategy in which changes of joint configurations that are irrelevant to success at the task are selectively released from control.
Learning of action through adaptive combination of motor primitives
TLDR
This work shows that humans learn the dynamics of reaching movements through a flexible combination of primitives that have gaussian-like tuning functions encoding hand velocity, and finds close agreement between the predicted limitations and the subjects’ adaptation to new force fields.
...
...