Riemannian geometric approach to human arm dynamics, movement optimization, and invariance

Phys Rev E Stat Nonlin Soft Matter Phys. 2011 Mar;83(3 Pt 1):031927. doi: 10.1103/PhysRevE.83.031927. Epub 2011 Mar 31.


We present a generally covariant formulation of human arm dynamics and optimization principles in Riemannian configuration space. We extend the one-parameter family of mean-squared-derivative (MSD) cost functionals from Euclidean to Riemannian space, and we show that they are mathematically identical to the corresponding dynamic costs when formulated in a Riemannian space equipped with the kinetic energy metric. In particular, we derive the equivalence of the minimum-jerk and minimum-torque change models in this metric space. Solutions of the one-parameter family of MSD variational problems in Riemannian space are given by (reparameterized) geodesic paths, which correspond to movements with least muscular effort. Finally, movement invariants are derived from symmetries of the Riemannian manifold. We argue that the geometrical structure imposed on the arm's configuration space may provide insights into the emerging properties of the movements generated by the motor system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arm / physiology*
  • Biomechanical Phenomena
  • Computer Simulation
  • Humans
  • Kinetics
  • Male
  • Models, Biological
  • Models, Statistical
  • Models, Theoretical
  • Movement*
  • Psychomotor Performance / physiology*
  • Range of Motion, Articular / physiology
  • Reaction Time / physiology
  • Space Perception / physiology*
  • Torque