Models and architectures for motor control: Simple or complex?

For the purpose of motor coordination, the nervous system faces a complex control problem, involving redundant degrees of freedom, nonlinear dynamics of limbs and actuators, noise, and perturbations. Models and architectures have been proposed to describe motor coordination in terms of computational processes, and identify possible simplifying strategies that would alleviate the workload of the nervous system. Here, we review several strategies ranging from biomechanical to function levels. We conclude that none of the proposed strategies actually tackle the overall problem of motor coordination. Then we present a principled approach that provides an overarching account to motor control.