Inferring motor plan complexity using a modified principal component analysis

While compliant behavior of the human arm is clearly an important contributor to stable interactions with the environment, the extent to which these properties of the arm are represented or ignored by the central nervous system in formulating motor plans remains unclear. Since model-based analyses (such as the various equilibrium-point models require a priori (and difficult to verify) assumptions about the internal structure of the neuromuscular system in order to test their predictions, we propose a model-independent approach to measuring the complexity of motor plans.