A neural pattern generator that tunes into the physical dynamics of the limb system

A model is presented in which a spinal circuit generates oscillatory output to a pendular limb via the muscles which, in turn, modulates the frequency of the spinal circuit. This model is based on a new theory of biological motor control which claims that motor behavior emerges from the coupling or interaction of the neural dynamics of the central nervous system and the physical dynamics of the limb system. Simulation results indicate that limit cycle stability in motor behavior can arise from such a coupling. It is also shown that these limit cycle frequencies scale with the physical length of the limb in accord with the resonant frequency of the limb and in agreement with human experimental data. Motor learning is treated as an increase in the efficacy of proprioceptive information and is shown to result in performance closer to the resonant frequency of the physical system